United States
Environmental Protection
Agency
Office of Research and
Development
Washington DC 20460
EPA/600/R-95/178
April 1996
&EPA
ICR Microbial Laboratory
Manual
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ICR MICROBIAL LABORATORY MANUAL
by
G. Shay Fout, Ph.D., Frank W. Schaefer III, Ph.D., James W. Messer, Ph.D.,
Daniel R. Dahling and Ronald E. Stetler
Biohazard Assessment Research Branch
Human Exposure Research Division
Cincinnati, Ohio 45268
NATIONAL EXPOSURE RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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NOTICE
The ICR Microbial Laboratory Manual was prepared by the authors in response to a
request from the Office of Water for support in ICR implementation. The methods
and laboratory approval components contained in the manual were based upon
consensus agreements reached at several workshops attended by industry, academia
and U.S. EPA personnel and input from the ICR Microbiology Implementation team,
which consisted of U.S. EPA personnel from the Office of Research and Develop-
ment, Office of Water and representatives from Regional Offices. The manual has
been peer reviewed by experts outside of U.S. EPA in accordance with the policy of
the Office of Research and Development. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
ACKNOWLEDGMENTS
The contributions from Robert S. Safferman, Robert H. Bordner and John A. Winter,
the helpful suggestions from members of the ICR Microbiology Implementation
Team, the graphical support of Fred P. Williams Jr. and the secretarial assistance of
Mary Ann Schmitz and Cordelia Nowell are greatly appreciated.
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TABLE OF CONTENTS
NOTICE ii
ACKNOWLEDGMENTS ii
TABLE OF CONTENTS iii
LIST OF FIGURES vi
LIST OF TABLES vii
SECTION I. INTRODUCTION 1-1
BACKGROUND ON THE INFORMATION COLLECTION RULE (ICR) 1-1
ENSURING DATA QUALITY FOR THE ICR 1-2
SECTION II. LABORATORY QUALITY ASSURANCE PLAN II-l
SECTION III. LABORATORY APPROVAL PROCESS III-l
CERTIFICATION AND LABORATORY APPROVAL PROGRAMS III-l
DESCRIPTION OF APPROVAL PROCEDURE III-l
Application for Approval III-2
Quality Control Samples III-2
Performance Evaluation Samples III-3
On-Site Laboratory Evaluation III-4
Special Approval Requirements III-4
SECTION IV. QUALITY CONTROL IV-1
CLOSTRIDIUMMETHOD-SPECIFIC QC IV-1
PROTOZOAN AND VIRUS METHODS-SPECIFIC QC IV-1
Protozoan Methods-Specific Assay Controls IV-1
Virus Monitoring Protocol Assay Controls IV-3
Quality Control Samples IV-4
INTRALABORATORY QC PROCEDURES IV-7
INTERLABORATORY QC PROCEDURES IV-9
RECORDING AND REPORTING QC DATA IV-9
LITERATURE CITED IV-10
SECTION V. ON-SITE LABORATORY EVALUATION V-l
GENERAL EVALUATION CRITERIA V-l
ICR Laboratory Consultant V-l
Evaluation Scheduling V-l
in
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SECTION VI. LABORATORY APPROVAL STATUS VI-1
APPROVAL CLASSIFICATION VI-1
Laboratories VI-1
Principal Analysts/Analysts VI-1
CRITERIA FOR CHANGING APPROVAL STATUS VI-2
Changing Laboratory Approval Status VI-2
Changing Analyst Approval Status VI-2
SYSTEM FOR NOTIFYING UTILITIES OF LABORATORY STATUS VI-5
SECTION VII. ICR PROTOZOAN METHOD FOR DETECTING GIARDIA CYSTS
AND CRYPTOSPORIDIUMOOCYSTS VII-1
TABLE OF CONTENTS VII-1
PART 1 - SCOPE VII-4
PART 2 - TERMINOLOGY VII-4
PART 3 - SUMMARY OF TEST METHOD VII-5
PART 4 - SIGNIFICANCE AND USE VII-5
PART 5 - INTERFERENCES VII-5
PART 6 - APPARATUS VII-6
PART 7 - REAGENTS VII-8
PART 8 - PRECAUTIONS VII-11
PART 9 - SAMPLING VII-11
PART 10 - ASSAY PROCEDURE VII-17
PART 11 - EDUCATION, TRAINING AND PROFICIENCY VII-32
PART 12 - KEY WORDS VII-33
APPENDIX VII-1. CLEANING THE MANIFOLD AND WELLS VII-34
APPENDIX VII-2. SAMPLE CALCULATION VII-35
APPENDIX VII-3. GIARDIA REPORT FORM VII-37
APPENDIX VII-4. CRYPTOSPORIDIUMKEPOWI FORM VII-38
APPENDIX VII-5. MICROSCOPE ADJUSTMENTS VII-39
SECTION VIII. VIRUS MONITORING PROTOCOL FOR THE ICR VIII-1
TABLE OF CONTENTS VIII-1
PART 1 — SAMPLE COLLECTION PROCEDURE VIII-4
PART 2 — SAMPLE PROCESSING VIII-16
PART 3 — TOTAL CULTURABLE VIRUS ASSAY VIII-23
PART 4 — CELL CULTURE PREPARATION AND MAINTENANCE VIII-30
PART 5 — STERILIZATION AND DISINFECTION VIII-40
PART 6 — BIBLIOGRAPHY AND SUGGESTED READING VIII-43
PART 7 — VENDORS VIII-46
PART 8 — EXAMPLES VIII-48
PART 9 — DATA SHEETS VIII-63
IV
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SECTION IX. COLIPHAGE ASSAY IX-1
ASSAY COMPONENTS IX-1
SAMPLE PROCESSING IX-2
SOMATIC COLIPHAGE ASSAY IX-2
MALE-SPECIFIC COLIPHAGE ASSAY IX-5
SECTION X. MEMBRANE FILTER METHOD FOR K coli X-l
SECTION XI. MEMBRANE FILTRATION METHOD FOR C. perfringens XI-1
APPENDIX A. VERIFICATION OF STATE CERTIFICATION ApA-1
APPENDIX B. APPLICATION FOR LABORATORY APPROVAL ApB-1
MINIMAL REQUIREMENTS FOR VIRUS LABORATORIES ApB-2
MINIMAL REQUIREMENTS FOR PROTOZOAN LABORATORIES ApB-9
APPENDIX C. CHECKLIST FOR LABORATORY APPROVAL FOR GIARDIA
AND CRYPTOSPORIDIUM ApC-1
APPENDIX D. CHECKLIST FOR LABORATORY APPROVAL FOR TOTAL
CULTURABLE VIRUS ApD-1
SECTION I - LABORATORY-SPECIFIC INFORMATION ApD-2
SECTION II - ANALYST-SPECIFIC INFORMATION ApD-11
DESCRIPTION OF CHECKLIST FOR LAB APPROVAL FOR VIRUS
ANALYSIS ApD-13
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LIST OF FIGURES
FIGURE VI-1. ICR - Microbiology Decision Tree VI-3
FIGURE VI-2. Criterion #1 Decision Tree VI-4
FIGURE VI-3. Criterion #2 Decision Tree VI-6
FIGURE VII-1. Raw Water Sampling Apparatus VII-13
FIGURE VII-2. Finished Water Sampling Apparatus VII-14
FIGURE VII-3. Ten-Place Manifold with Stainless Steel Wells VII-21
FIGURE VII-4. Ten-Place Hoefer Manifold Membrane Labeling Diagram VII-23
FIGURE VII-5. Methods for Scanning Water Filter Membrane VII-29
FIGURE VIII-1. Standard Filter Apparatus VIII-5
FIGURE VIII-2. Additional Modules for the Standard Filter Apparatus VIII-9
FIGURE X-l. Precision Estimates for E. coli in Water by the M-TEC Method X-ll
VI
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LIST OF TABLES
TABLE IV-1. Reagent Grade Water Purity Parameters IV-9
TABLE VII-1. Ethanol/Glycerol Series VII-10
TABLE VIII-1. Guide for Preparation of BGM Stock Cultures VIII-36
TABLE VIII-2. Preparation of Virus Assay Cell Cultures VIII-37
TABLE VIII-3. Water Quantity to be Added to Vessels during Autoclaving VIII-41
TABLE XI-1. Sample Volume to Obtain Colony Count on Membrane Filters XI-11
TABLE XI-2. Statistical Evaluation of Results (CFU/100 mL) XI-13
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SECTION I. INTRODUCTION
BACKGROUND ON THE INFORMATION COLLECTION RULE
The United States Environmental Protection Agency (U.S. EPA) instituted a formal
regulation negotiation process in 1992 to develop the Disinfectant/Disinfection By-Product
(D/DBP) Rule.1 The Advisory Committee that was established to negotiate the regulation
included representatives from the water industry, State health agencies, environmental groups,
consumer groups, and the U.S. EPA. During negotiations, the Advisory Committee realized
that setting strict limits on the levels of disinfectants and disinfection by-products (D/DBPs) in
drinking water could result in increasing risk of waterborne disease from pathogens. To
balance the risks from pathogens and chemicals, the Advisory Committee made several
recommendations and the final result was the development of three new drinking water
regulations.
The Disinfectant/Disinfection By-Product Rule was the primary rule negotiated. The
Advisory Committee recommended a two step approach to regulating the D/DBPs with the
first stage of the regulation coinciding with a regulation to ensure microbial safety of the water.
The Stage 1 D/DBP Rule: 1) sets limits on the amount of disinfectants allowed in drinking
water; 2) reduces the limits on total trihalomethanes (TTHMs) from 100 //g/L to 80 //g/L; 3)
sets limits on additional DBFs (sum of five haloacetic acids [HAAS], chlorite, and bromate); 4)
requires the use of enhanced coagulation by utilities treating surface water containing total
organic carbon (TOC) concentrations above certain levels; and 5) applies to all community and
non-transient noncommunity water systems.
The second rule developed during the negotiation process is the Enhanced Surface Water
Treatment Rule (ESWTR). It specifies levels of treatment to control pathogens in drinking
water based on microbial quality of the source water. This rule would become effective at the
same time as the Stage 1 D/DBP Rule.
The third rule that was recommended by the Advisory Committee is the Information
Collection Requirements Rule (ICR). This rule addresses data needs in three areas.
The most critical element of the ICR involves the collection of data on the concentrations
of specific microbes. Cryptosporidium, Giardia and total culturable viruses are being moni-
tored in surface waters that are used to produce drinking water and in drinking water, when
high concentrations are found in surface water. In addition, data are being collected on the
concentrations of indicators of human pollution in these waters. The data collected during the
ICR will be used in the development of the ESWTR.
J57 FR 53866, November 13, 1992
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The second element of the ICR involves the collection of treatment plant operational data
and monitoring of the source water and drinking water for general water quality characteristics,
DBFs, and surrogates for DBFs and DBF precursors. These data from the ICR will be used to:
1) characterize the source water parameters that influence DBF formation; 2) determine
concentrations of DBFs in drinking water; 3) refine models for predicting DBF formation; and
4) establish cost-effective monitoring techniques. Development of the Stage 2 D/DBP rule is
dependent upon analyses of these data.
The third element of the ICR requires some systems to conduct bench or pilot scale
studies on DBF precursor removal using either granular activated carbon or membrane
filtration. The purposes of these Precursor Removal/ICR studies are: 1) to obtain more
information on the cost effectiveness of these technologies for reducing DBF levels; and 2) to
decrease the time systems would need to install such technology, if it was required under a
Stage 2 D/DBP rule.
ENSURING DATA QUALITY FOR THE ICR
One of the major issues during development of the ICR concerned the quality of the data
that would be generated during the monitoring period. The Advisory Committee recognized
that the data must be both accurate and precise to meet the ICR objectives. Everyone realized
the difficulty in ensuring data quality considering that the data are to be generated by many
laboratories. Maintaining data comparability between laboratories would be necessary to use
the data for sophisticated correlational analyses and to have data that are useful for predicting
DBF formation as a function of water quality conditions. The Advisory Committee felt that
the only way to ensure that useable data is obtained is for the U.S. EPA to assist the drinking
water industry in identifying qualified laboratories for performing the analyses required by the
ICR.
In August 1993, U.S. EPA convened a technical workgroup to assist in developing
approaches for ensuring microbiological data quality. Representatives from utility, state and
commercial laboratories were present at the three day meeting. Persons were invited to this
meeting based on their expertise in one or more of the following areas: 1) analyzing for
microorganisms; 2) day-to-day management of laboratory operations; and 3) drinking water
laboratory certification programs.
The technical workgroup made several general recommendations on approaches to
ensure data quality. These recommendations were included in the proposed ICR.2 The work-
group's recommendations and public comments to the proposed rule were used by the U.S.
EPA to develop this manual.
259 FR 6332, February 10, 1994
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SECTION II. LABORATORY QUALITY ASSURANCE PLAN
All laboratories analyzing samples for the ICR will be required to adhere to defined
quality assurance procedures to ensure that generated analytical data are scientifically valid
and are of known and acceptable precision and specificity. To facilitate the accomplishment of
these goals, each laboratory must have a written description of its quality assurance activities, a
QA plan, describing the QA management of day to day routine operations. The plan must be
available for inspection for ICR laboratory approval and during the time which the laboratory
is performing ICR measurements.
The laboratory's QA plan should be a separately prepared text. However, documentation
for some of the listed QA plan items can be made by reference to appropriate documents, such
as the laboratory's SOPs, U.S. EPA Methods, or to Standard Methods for the Examination
of Water and Wastewater. Laboratories currently certified for coliform analyses under the
Drinking Water Certification program may use their current QA Plan for ICR bacteriological
monitoring. Items pertinent to the protozoan or virus analyses may be placed in an addendum.
This addendum must contain all the QC criteria for these analyses.
The following items should be addressed in each QA plan:
LABORATORY ORGANIZATION AND RESPONSIBILITY
1. Include a chart showing the laboratory organization and line authority, including QA
Managers.
2. List the key individuals who are responsible for ensuring the production of valid measure-
ments and the routine assessment of QC measurements
3. Specify who is responsible for internal audits and reviews of the implementation of the
QA plan and its requirements.
PERSONNEL
1. List analysts' academic background and water analysis experience.
2. Describe training available to keep personnel up to date on regulations, methods and/or
TQM.
FACILITIES
Describe the following:
1. Arrangement and size of laboratories
2. Bench space
3. Storage space
4. Lighting
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5. Air system
6. Lab reagent water system
7. Waste disposal system
8. Safety considerations
FIELD SAMPLING PROCEDURES
1. Identify samples collected, describe how samples are collected, sample containers,
holding, transport times, and temperature.
2. Describe sample identification and information recording system, chain-of-custody
procedure, if applicable.
LABORATORY SAMPLE HANDLING PROCEDURES
1. Describe sample storage conditions.
2. Describe the laboratory's sample tracking system; specify procedures used to maintain the
integrity of all samples, i.e., logging, tracking samples from receipt by laboratory through
analysis to disposal.
EQUIPMENT
For each equipment item describe the following:
1. Specifications
2. Calibration procedures, frequency, standards
3. Quality control records
4. Preventive maintenance and schedules, documentation
SUPPLIES
Describe the specifications for major supplies, including storage conditions for reagents
and media:
1. Laboratory glassware and plasticware
2. Chemicals, reagents, dyes and culture media
3. Filters
LABORATORY PRACTICES
Describe the following practices:
1. Preparation of reagent-grade water
2. Glassware washing and preparation
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3. Sterilization procedures
ANALYTICAL PROCEDURES
1. Describe all reference methods used
2. State that the analytical methods described in this manual will be followed
3. Identify available SOPs
QUALITY CONTROL TOO CHECKS
Describe how the following are performed:
1. Confirmation/verification procedures, frequency
2. Sterility controls
3. Replicate analyses; frequency
4. QC samples, source; frequency
5. PE samples, source; frequency
6. Spiked samples
7. Between analyst deviation
DATA REDUCTION. VERIFICATION. VALIDATION AND REPORTING
Describe the procedures for the following:
1. Data reduction, e.g., conversion of raw data to mg/L., coliforms/100 mL, etc.
2. Ensuring the accuracy of data transcription and calculations.
3. Validation, e.g., how are ICR QC requirements met?
4. Reporting, including procedures and format for reporting data to utilities/EPA
CORRECTIVE ACTION CONTINGENCIES
1. Define the laboratory response to obtaining unacceptable results from PE or QC samples
and from internal QC checks
2. Identify persons with responsibility to take corrective action
3. Describe how the actions taken and the effectiveness of the actions taken will be docu-
mented
RECORD KEEPING
1. Describe how records are to be maintained (e.g., electronically, hard copy, etc.)
2. Describe how long records are to be kept.
3. State where records are to be stored.
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A laboratory QA plan should be concise but responsive to the above-listed items.
Minimizing paperwork while improving dependability and quality of data are the intended
goals "Preparation Aids for the Development of Category I Quality Assurance Plans,"
EPA/600/8-91/003, is a document laboratories may find useful in preparing a QA plan for the
ICR. It can be obtained by calling the National Risk Management Research Laboratory,
Technical Information Branch at 513-569-7562. Not all of the above sections are described in
the project plan guidance (i.e., laboratory sample handling and record keeping) and the goals
of a lab QA Plan in general are different from the goals of a QAPP. The former describes QA
Management of day to day routine operations and the latter describes goals, interactions and
procedures for a specific project. By adding to the QA lab plan what will be done to meet ICR
criteria, the lab will develop a Project Plan for the ICR responsibilities.
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SECTION III. LABORATORY APPROVAL PROCESS
CERTIFICATION AND LABORATORY APPROVAL PROGRAMS
Laboratories requesting approval to perform quantitative analyses for total coliforms and
fecal coliforms or E. coli in source and drinking water for the ICR must be certified under the
drinking water laboratory certification program as specified by 40 CFR 142.10(b)(4) and
141.28. In this program, the U.S. EPA certifies the principal State laboratory and with certain
exceptions other laboratories in non-primacy states (40 CFR 142.10). Each State certifies all
other drinking water laboratories within the State.
Laboratories that will perform quantitative analyses for total coliforms and fecal coliforms
or E. coli in source water and drinking water must provide validation of certification under the
drinking water laboratory certification program. These laboratories are requested to complete
the Verification of State Certification form (Appendix A) and return the form to the U.S. EPA
Office listed.
The drinking water laboratory certification program does not address analyses for the
pathogens of relevance to the ICR — Giardia, Cryptosporidium and total culturable viruses.
Rather than broaden the drinking water laboratory certification program to cover these
organisms, U.S. EPA has developed a separate program for the ICR, using the term "labora-
tory approval" rather than "laboratory certification."
The final ICR Rule does not require that water systems monitor for Clostridium or coli-
phage and these organisms are not included in the laboratory approval program. However,
water systems may monitor for them and submit their data to the ICR database. If this option
is chosen, the methods and QC conditions described in this manual should be followed.
A major difference between the drinking water laboratory certification and laboratory
approval programs is that the latter requires that certain laboratory personnel be individually
approved. All principal analysts must be approved for protozoan analyses (Giardia and
Cryptosporidium). All principal analysts and all analysts must be approved for analysis of
total culturable viruses. Each approved laboratory and each individual who must be individu-
ally approved will be assigned a unique identification (ID) number or code.
DESCRIPTION OF APPROVAL PROCEDURE
Laboratory approval will require: (1) submission and acceptance of an application for
approval, (2) satisfactory analyses of unknown Performance Evaluation (PE) samples; and (3)
passing an on-site laboratory evaluation.
The term "analyst" will be used in the remainder of this section to refer to all principal
analysts and analysts who must be individually approved. Only these analysts must obtain
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successful performance with PE samples. They will also be required to demonstrate method
proficiency during the on-site visit.
Application for Approval:
The laboratory approval process for pathogen testing will begin when the laboratory
director makes a formal request for approval to the:
ICR Laboratory Coordinator
U.S. EPA, Office of Ground Water & Drinking Water
Technical Support Division
26 West Martin Luther King Drive
Cincinnati, OH 45268
Upon receipt of the formal request for approval, the U.S. EPA Laboratory Coordinator
will provide the requesting laboratory an application form to be completed and returned. Only
laboratories that meet the minimal facility, equipment and personnel requirements described in
the application package will be considered for approval. The application package is repro-
duced as Appendix B
Laboratories will be notified in writing when their application for approval is accepted.
Laboratories meeting the minimal requirements will receive one copy each of the appropriate
sampling and methods videos and their accompanying guides and a copy of this manual. In
addition, U.S. EPA will provide buffalo green monkey kidney (BGM) cells and an MPN
computer program to all laboratories meeting minimal requirements for virus analyses. All
laboratories meeting minimal requirements for protozoan analyses will be supplied a spread-
sheet for calculating Giardia cyst and Cryptosporidium oocyst concentrations. The supplied
cell line and computer programs must be used during ICR monitoring to ensure uniform
results.
Quality Control Samples:
Quality Control (QC) samples containing known Giardia cyst, Cryptosporidium oocyst
and virus concentrations will be provided to analysts requesting approval. These samples,
which are described in detail in Section IV, may be used for internal QC checks and to gain
method proficiency. Successful analyses on QC samples will be required for ongoing appro-
val during the ICR monitoring period. The data from QC samples for ongoing approval must
be entered into an ICR Laboratory Quality Control System software developed to track QC
data and sent monthly in electronic form to the ICR Data Center at the address given below.
The package containing the diskette with QC data must be postmarked no later than the last
day of each month.
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U.S.EPA(ICR4600)
ICR Data Center
Room 1111 East Tower
401 M Street, SW
Washington, D.C. 20460
Performance Evaluation Samples:
Under the laboratory approval program, qualified laboratory personnel must analyze
satisfactorily PE sample sets to become approved and then subsequent sets every month to
maintain approval. Each analyst must process the PE samples for GiardialCryptosporidium or
total culturable viruses as normal samples as described in the method protocols (Section VII
and Section VIII, respectively). While personnel who do not have to be individually
approved are not required to analyze PE samples, they must process the same portions of PE
samples for analysts that they would for actual water samples to be tested. A hard copy of the
PE data must be sent directly to the ICR Laboratory Coordinator at the address listed above.
The hard copy of the data must not include the laboratory name, address or any other identify-
ing information. This information should be included only on a cover letter accompanying the
data.
A set of PE samples for initial approval will have seven to ten samples. For laboratories
analyzing protozoan samples, PE samples will consist of 1 |im nominal porosity filters
containing either a blank synthetic matrix or a mixture ofGiardia cysts and Cryptosporidium
oocysts in various concentrations in a synthetic matrix. For laboratories analyzing virus
samples, PE samples will consist of 1MDS filters containing either a blank synthetic matrix or
attenuated poliovirus type 3 in various concentrations in a synthetic matrix.
A set of PE samples for ongoing approval will have two samples. The samples types will
be the same as for initial approval. Conditions for maintaining ongoing approval are described
in Section VI.
A standard statistical method will be used to determine the mean concentrations, variation
and pass/fail acceptance limits for PE samples using either data from reference laboratories or
overall data for each lot from all laboratories.
If an analyst fails the initial PE sample set, the analyst will have a second chance with
another sample set within three months. Analysts who fail PE samples should contact the ICR
Laboratory Coordinator for suggestions on remedies for the problem, since failure to meet
acceptance levels on a second PE sample set will result in the analyst being excluded from the
program.
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On-Site Laboratory Evaluation:
The primary purpose of the laboratory on-site evaluation is to ensure valid data. The
immediate objective is to evaluate the facilities and equipment of the laboratory and the
analyst's ability to adhere to the monitoring protocols. The use of uniform methodology
makes it possible to compare data generated by the different laboratories. The laboratory
evaluation criteria that will be used during site visits is given in Section V.
Special Approval Requirements:
1. Sample Collections:
Appropriate sample collection is an important part of the ICR process. Sample collectors
will be provided a videotape and accompanying guide describing the specified sampling
procedures by the U.S. EPA. Although sample collection will be performed by the utility, the
analytical laboratory must supply the utility with properly cleaned or sterile sampling apparatus
modules and assist the sample collectors by providing information and guidance on the
procedures and proper use of equipment to ensure sample integrity.
2. Sample Archiving:
By applying for U.S. EPA approval for virus analyses, a laboratory agrees to prepare
virus archive samples as described in the Virus Monitoring Protocol (see Section VIII).
Each water system will notify its contracted virus analytical laboratory when the following
conditions trigger archiving requirements:
a. Virus detection in finished water: when a system learns that viruses were detected in
any previous finished water sample, all subsequent source and finished water samples
must be archived for the remainder of the ICR monitoring period.
b. Virus detected at a level of 10,000 MPN units per 100 L (approximately 100
infectious virus particles per liter) in source water: when a system learns that viruses
were detected in any previous source water sample at this density, all subsequent source
and finished water samples must be archived for the remainder of the ICR monitoring
period.
Archive samples must be frozen at -70°C and shipped on dry ice to the ICR Laboratory
Coordinator at the address listed above; however, the samples may be stored by the analytical
laboratory at -70°C and shipped periodically to the U.S. EPA as a batch.
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SECTION IV. QUALITY CONTROL
Laboratories that perform microbiological analyses for the ICR are required to use the
methods contained in this manual. These methods identify methods-specific quality control
(QC) procedures which must be followed to ensure accurate and precise data. In addition to
methods-specific QC procedures, laboratories must practice intralaboratory QC, the day-to-day
checks made on internal operations, and interlaboratory QC, the maintenance of minimal
standards established among a group of participating laboratories.
The following are descriptions of ICR methods-specific, intralaboratory, and interlabora-
tory QC procedures.
CLOSTRIDKMMETHOD-SPECIFIC PC
Analytical laboratories are responsible for developing their own internal QC program and
must run positive and negative controls as described in Section XI (subsection 9.4). U.S. EPA
will not supply QC samples.
PROTOZOAN AND VIRUS METHODS-SPECIFIC PC
A U.S. EPA contractor will prepare and ship QC stock suspensions ofGiardia lamblia
cysts and Cryptosporidium parvum oocysts and both high-titered and low-titered QC samples
of attenuated poliovirus type 3. Upon arrival, the protozoan QC samples must be stored at 4°C
and the virus QC samples at -70°C. The protozoan QC stock suspensions and the high-titered
poliovirus sample may be used to gain proficiency with the methods and for the development
of the laboratory's own QC tests. Methods-specific QC procedures will require that the
protozoan stock suspensions be diluted. Instructions for dilution will accompany the suspen-
sions.
Protozoan Methods-Specific Assay Controls:
The purpose of these controls is to assure that the assay reagents for the ICR Protozoan
Method For Detecting Giardia Cysts and Cryptosporidium Oocysts In Water By A
Fluorescent Antibody Procedure (see Section VII) are functioning, that the assay proce-
dures have been properly performed, and that the microscope has been adjusted and aligned
properly.
A. Membrane Filter Preparation:
Use the INDIRECT FLUPRESCENT ANTIBPDY PRPCEDURE to prepare at least one
positive and one negative IFA control for Giardia cysts and Cryptosporidium oocysts each
time the manifold is used.
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B. Negative IF A Control for Giardia/Cryptosporidium:
Step 1. Add 1.0 mL IX PBS to one well of the manifold containing a Sartorius cellulose
acetate filter on top of a membrane support filter. Perform the Indirect Fluorescent Antibody
Staining and Filter Mounting steps.
Step 2. Using epifluorescence, scan the negative control membrane at no less than 200X
total magnification for apple-green fluorescence ofGiardia cyst and Cryptosporidium oocyst
shapes.
Step 3. If no apple-green fluorescing cyst or oocyst shapes are found, and if background
fluorescence of the membrane is very dim or non-existent, continue with examination of the
water sample slides.
If apple-green fluorescing cyst or oocyst shapes are found, discontinue examination since
possible contamination of the other slides is indicated. Clean the equipment, recheck the
reagents and procedure and repeat the assay using additional aliquots of the sample.
C. Positive IF A Control for Giardia/Cryptosporidium:
Step 1. Add 500-1000 Giardia lamblia cysts and 500-1000 Cryptosporidium parvum
oocysts or the Ensys positive control antigen (as specified in the kit) to one well of the
manifold containing a Sartorius cellulose acetate filter on top of a membrane support filter.
Perform the Indirect Fluorescent Antibody Staining and Filter Mounting steps.
Step 2. Using epifluorescence, scan the positive control slide at no less than 200X total
magnification for apple-green fluorescence ofGiardia cyst and Cryptosporidium oocyst
shapes. Background fluorescence of the membrane should be either very dim or non-existent.
Cryptosporidium oocysts may or may not show evidence of oocyst wall folding, which is
characterized under epifluorescence by greater concentrations of FITC along surface fold
lines, depending upon the manner in which the oocysts have been treated, and the amount of
turgidity they have been able to maintain.
If no apple-green fluorescing Giardia cyst or Cryptosporidium oocyst shapes are
observed, then the fluorescent staining did not work or the positive control cyst preparation
was faulty. Do not examine the water sample slides for Giardia cysts and Cryptosporidium
oocysts. Recheck reagents and procedures to determine the problem.
Step 3. If apple-green fluorescing cyst and oocyst shapes are observed, change the
microscope from epifluorescence to the 100X oil immersion Hoffman modulation® or
differential interference contrast objective.
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At no less than 1000X total oil immersion magnification, examine Giardia cyst shapes
and Cryptosporidium oocyst shapes for internal morphology.
The Giardia cyst internal morphological characteristics include one to four nuclei,
axonemes, and median bodies. Giardia cysts should be measured to the nearest 0.5 jim with a
calibrated ocular micrometer. Record the length and width of the cysts and the morphological
characteristics observed. Continue until at least three Giardia cysts have been detected and
measured in this manner.
The Cryptosporidium oocyst internal morphological characteristics include one to four
sporozoites. Examine the Cryptosporidium oocyst shapes for sporozoites and measure the
oocyst diameter to the nearest 0.5 jim with a calibrated ocular micrometer. Record the size of
the oocysts and the number, if any, of the sporozoites observed. Sometimes a single nucleus is
observed per sporozoite. Continue until at least three oocysts have been detected and mea-
sured in this manner.
Virus Monitoring Protocol Assay Controls :
A. Negative Assay Control for the Virus Monitoring Protocol for the ICR (see Section
Vin): Inoculate a BGM culture with 0.15 M sodium phosphate, pH 7.0-7.5, using the
procedures in Section VIII, Part III — Total Culturable Virus Assay Do not report data
from associated water samples if positive CPE is obtained in this control. Do not process any
more samples until the reason(s) for the positive result is determined.
B. Positive Assay Control for the Virus Monitoring Protocol for the ICR (see Section
Vin): Inoculate a BGM culture with 0.15 M sodium phosphate, pH 7.0-7.5, containing 20
PFU of attenuated poliovirus type 3, using the procedures in Section Vin, Part III — Total
Culturable Virus Assay. Do not report data from associated water samples if CPE is not
observed in this control. Do not process any more samples until the reason(s) for the negative
result is determined.
C. Negative Assay Control for the optional Coliphage Assay (see Section IX): Add 1 mL
of buffered 1.5% beef extract to a 16 x 150 mm test tube. Continue with Step 2 of the
Procedure for Somatic or Male-Specific Coliphage Assay Do not report data from
associated water samples if plaques are observed in this control. Do not process any more
samples until the reason(s) for the positive result is determined.
D. Positive Assay Control for the optional Coliphage Assay (see Section IX): Add 1 mL of
the diluted somatic or male-specific positive control to another 16 x 150 mm test tube.
Continue with Step 2 of the Procedure for Somatic or Male-Specific Coliphage Assay Do
not report data from associated water samples if the positive control counts are more than one
log below their normal average. Do not process any more samples until the reason(s) for the
below normal positive result is determined.
IV-3
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Quality Control Samples:
A. Giardia cyst and Cryptosporidium Oocyst Quality Control Samples:
1. Negative QC Sample Preparation: This control is a check on equipment, materials,
reagents and technique. It involves processing a 1 |im nominal porosity cartridge
filter as if it were an unknown using the indicated procedures from the ICR Proto-
zoan Method for Detecting Giardia Cysts and Cryptosporidium Oocysts in
Water by a Fluorescent Antibody Procedure (see Section VII).
Step 1. Process a 1 |im nominal porosity cartridge filter using the FILTER ELU-
TION AND CONCENTRATION. FLOTATION PURIFICATION and INDIRECT
FLUORESCENT ANTIBODY procedures in Section VII.
Step 2. Examine the entire concentrate for Giardia cysts and Cryptosporidium
oocysts using the Microscopic Examination procedure of Section VII. If any cysts
or oocysts are detected, do not process any more unknown samples until the
source(s) of the contamination is located and corrected.
2. Positive QC Giardia and Cryptosporidium Sample Preparation: The purpose of this
control is to assure that the laboratory can recover cysts and oocysts with the indi-
cated procedures from the ICR Protozoan Method for Detecting Giardia Cysts
and Cryptosporidium Oocysts in Water by a Fluorescent Antibody Procedure
(see Section VII) when they are spiked into a sample at a known level.
Step 1. Seed 40 L (10 gal) of reagent-grade water with 1000 Giardia cysts and
2000 Cryptosporidium oocysts. Pass the spiked water through a 1 |im nominal
porosity cartridge filter using the procedures found in Part 9 - Sampling of Section
VII
Step 2. Process the filtered water using the FILTER ELUTION AND CONCEN-
TRATION. FLOTATION PURIFICATION and INDIRECT FLUORESCENT
ANTIBODY procedures in Part 10 of Section VII.
Step 3. Examine the entire concentrate for Giardia cysts and Cryptosporidium
oocysts using the Microscopic Examination procedure of Part 10 of Section VII
It is not necessary to identify internal morphological characteristic using differential
interference contrast microscopy. If cysts and oocysts are not detected, do not
process any more unknown samples until the reason(s) for not recovering cysts and
oocysts is determined and corrected.
IV-4
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B. Viral Quality Control Samples:
1. Negative QC Viral Sample Preparation: This control is a check on equipment,
materials, reagents and technique. It involves processing a 1MDS filter and examin-
ing that sample as if it were an unknown using the indicated procedures from the
Virus Monitoring Protocol for the ICR (see Section VIII).
Step 1. Place a sterile 1MDS filter into a standard filter apparatus.
Step 2. Process and analyze the 1MDS filter using the procedures in Part 2 —
Sample Processing and Part 3 — Total Culturable Virus Assay of
Section VIII. If any virus is detected, do not process any more unknown
samples until the source(s) of the contamination is located and corrected.
2. Positive QC Viral Sample Preparation: The purpose of this control is to assure that
the laboratory can recover virus with the indicated procedures from the Virus
Monitoring Protocol for the ICR (see Section VIII) when virus is spiked into a
sample at a known level.
Step 1. Place 40.0 L of reagent grade water into a sterile polypropylene container.
Step 2. Thaw the low-titered virus QC sample containing 1 mL with 200 PFU of
virus. Add the entire contents of the vial into the reagent grade water and
rinse the vial with 1 mL of the water. Mix and pump the solution through a
standard apparatus containing a 1MDS filter using the procedures in Part
1 — Sample Collection Procedure of Section VIII
Step 3. Process and analyze the 1MDS filters containing QC stock virus using the
procedures in Part 2 — Sample Processing and Part 3 — Total Cultura-
ble Virus Assay of Section VIII. If virus is not detected, do not process
any more unknown samples until the reason(s) for not recovering virus is
determined and corrected.
3. Coliphage Assay: Quality Control Samples have not been developed for the coli-
phage assay. Each laboratory should plan and conduct its own internal QC checks.
C. Quality Control Batch:
All protozoan and virus samples processed by an analyst within one week's span shall be
considered to be a "batch". A week is defined as a Sunday to Saturday time frame. Each
sample result must be associated with a batch number. An appropriate positive and negative
QC sample set must be processed with each batch. In the case of the protozoan analysis, the
QC sample set should be processed at the beginning of the week's batch, if possible.
IV-5
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1. Failure to obtain both a positive value in the positive QC sample and a negative value
in the negative QC sample results in failure of the whole batch. Consequently, data
from that batch would be excluded from the ICR database.
2. Obtaining a positive value in the positive QC sample and a negative value in the
negative QC sample results in acceptance of the data from the whole batch. Data
must be reported for all of the samples in that batch.
D. Flagging of Sample Data not Meeting Other Quality Control Conditions:
Other quality control conditions are described in the protozoan and virus protocols.
Failure to comply with these conditions may decrease the pathogen concentrations, giving
false negative results or measured values that are lower than the actual levels in water samples.
If such a sample cannot be collected again within the time requirements of the final ICR rule, it
should be analyzed. The associated data should be flagged, and the reason for the flag placed
in the comment field of the database. The following flag conditions have been identified:
1. Thiosulfate not added to finished waters with disinfectant.
2. pH not reduced to below 8.0 for virus samples.
3. Collected sample volume outside the recommended range.
4. Partial or complete freezing of sample.
5. Sample shipped without ice or chemical ice.
6. Sample arrived at ambient temperature (insufficiently cooled - not cold to touch).
7. Maximum shipping holding time exceeded.
8. Maximum sample process or analysis time requirements exceeded.
9. Cytotoxicity in virus assays.
Samples that do not conform to other lab- or utility-specified QA conditions should be
treated according to the appropriate QA plans.
EPA will convert flagged data from "quantitative" to "qualitative" by changing all
positive values to "PD." All less than detection limit values will be changed to "ND." PD
indicates that pathogens were detected under conditions where pathogen levels are likely to be
higher than the value actually measured. ND indicates that pathogens were not detected either
IV-6
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due to their absence from samples or due to conditions that result in obtaining values that are
less than the detection limit.
Several conditions, including the lack of a temporal relationship between finished and raw
water samples and the possible addition of high pathogen numbers through recycling of filter
backwash water, create the possibility of observing higher pathogen levels in finished water
than in raw water. Due to this possibility, water systems must not flag such data, unless the
conditions listed above apply.
INTRALABORATORY PC PROCEDURES
The following minimal quality control procedures should be followed for laboratory equip-
ment, reagents and supplies. See Section V and Appendix C and D for detailed procedures as
they relate to the protozoa and virus methods.
pH meter:
Standardize the pH meter prior to each use with pH 7.00 and pH 4.00 standard buffers for
solutions with pH values less than 7.0 and pH 7.00 and pH 10.00 standard buffers for solutions
with pH values greater than 7.0.
Date standard buffer solutions upon receipt and when opened. Discard before expiration
date.
Balance (top loader or pan):
Calibrate balance monthly using Class S or S-l reference weights (minimum of three
traceable weights which bracket laboratory weighing needs) or weights traceable to Class S or
S-l weights. Calibrate non-reference weights annually with Class S or S-l reference weights.
Maintain service contract or internal maintenance protocol and maintenance records.
Conduct maintenance annually at a minimum.
Temperature Monitoring Device:
Check calibration of each in-use glass/mercury thermometer annually and of each in-use
dial thermometer quarterly, at the temperature used, against a reference National Institute of
Standards and Technology (NIST) thermometer or one that meets the requirements of NIST
Monograph SP250-23.
Recalibrate continuous recording devices annually which are used to monitor incubator
temperature using the NIST reference thermometer described above.
IV-7
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Incubator Unit:
Record temperature once per day for each workday in use.
Autoclave:
Record date, contents, sterilization time, and temperature for each cycle. Establish a
service contract or internal maintenance protocol, and maintain records.
Use maximum-temperature registering thermometer, heat sensitive tape, or spore strips or
ampules during each autoclave cycle and record temperature. Avoid overcrowding.
Check automatic timing mechanism with stopwatch quarterly.
Hot Air Oven:
Record date, contents, and sterilization time and temperature of each cycle.
Conductivity Meter:
Calibrate conductivity meter monthly with a 0.01 M KC1 solution, or lower concentration
if desired (see Method 120.1 in EPA, 1979 or Section 2510, "Conductivity" p 2-43, in
APHA, 1995). An in-line conductivity meter does not need to be calibrated.
Refrigerator:
Record temperature at least once per day for each workday in use.
Ultraviolet Lamp (if used):
Test lamp quarterly with UV light meter and replace if it emits less than 70% of initial
output or if agar spread plates containing 200 to 250 microorganisms, exposed to the UV light
for two minutes, do not show a count reduction of 99%. Other methods may be used to test a
lamp if they are as effective as the two suggested methods.
Glassware Washing:
Perform the Inhibitory Residue Test (APHA, 1995) on the initial use of a washing
compound and whenever a different formulation of washing compound or washing procedure
is used to ensure that glassware is free of toxic residues. Laboratories purchasing large
quantities of washing compound may avoid assay problems by testing the compound on an
annual basis.
IV-8
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Reagent Grade Water:
Test the quality of the reagent grade water or have it tested by a certified laboratory to
assure it meets the criteria in Table IV-1.
TABLE IV-1. REAGENT GRADE WATER PURITY PARAMETERS
Parameter
Conductivity
Pb, Cd, Cr, Cu, Ni, Zn
Total Chlorine Residual1
Heterotrophic Plate Count2
Bacteriological Quality of
Reagent Water3
Limits
>0.5 megohms-cm resistance or
<2 |imhos/cmat25°C
Not greater than 0.05 mg/L per
containment. Collectively, no
greater than 0. 1 mg/L
Nondetectable
<500/mL
Ratio of growth rate of 0.8-3.0
Frequency
Monthly
Annually
Monthly
Monthly
Annually
JDPD method not required if source water is not chlorinated.
2Pour plate method.
3Test for bacteriological quality of reagent water (APHA, 1995; or Bordner and Winter,
1978). Control water for the test is defined as double distilled water using a glass unit.
INTERLABORATORY PC PROCEDURES
EPA has decided to use Performance Evaluation (PE) studies as EPA's check on inter-
laboratory performance. PE samples will be distributed to the ICR laboratories on a monthly
basis See Performance Evaluation Samples in Section III
RECORDING AND REPORTING PC DATA
Records of sample information, microbiological analyses, and method and intralaboratory
QC test data are information that must be recorded and stored. Typically, the laboratory must
forward sample analytical reports to the treatment plant and retain copies for its own records.
Records of sample information, microbiological analyses, and method and intralaboratory QC
must be kept by the laboratory for at least five years. Microbiological analysis records and
methods QC data includes all raw data with calculations.
IV-9
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LITERATURE CITED
APHA. 1995. Standard Methods for the Examination of Water and Wastewater, 19th Ed.,
American Public Health Association, Washington, D.C., pp. 9-4 to 9-6.
Bordner, B. and J. Winter. 1978. Microbiological Methods for Monitoring the Environment.
U.S. Environmental Protection Agency Publication No. EPA-600/8-78-017, Cincinnati, OH,
pp. 200-203.
EPA. 1979. Methods of chemical analyses of water and wastes. U.S. Environmental Protection
Agency Publication No. EPA/600/4-79-020, (revised 1983), Cincinnati, OH.
IV-10
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SECTION V. ON-SITE LABORATORY EVALUATION
GENERAL EVALUATION CRITERIA
ICR Laboratory Consultant:
On-site laboratory evaluations will be conducted by an ICR Laboratory Consultant, who
will be a U.S. EPA employee or a contracted environmental microbiologist. The ICR Labora-
tory Consultant will record laboratory information during the site visit according to the
evaluation criteria listed below. U.S. EPA will use the recorded information to make all
decisions about laboratory approval. Contracted ICR Laboratory Consultants will not
participate in approval decisions.
Evaluation Scheduling:
A U.S. EPA person or contractor designated to schedule on-site evaluations will contact
the Director of the Laboratory to set a mutually agreeable date and time for the visit. The
evaluation will be scheduled at a time, if possible, that will result in minimal disruption of
laboratory activities; however, all personnel who will be analyzing ICR samples must be
available to perform the protozoan and/or viral tests for which approval is requested. As a
guide, a minimum of three days will be scheduled.
Before the on-site evaluation, the ICR Laboratory Consultant will review the information
submitted on the application and, if completed, the performance of each analyst on QC and PE
samples. If the laboratory has been previously evaluated in the drinking water program, the
ICR Laboratory Consultant will review that report to ensure that any applicable deviations,
problems, suggested changes, or improvements have been addressed and corrected.
At the start of the on-site evaluation, the ICR Laboratory Consultant will meet the
Laboratory Director and all members who will perform the test procedures to discuss the
general aspects of the laboratory evaluation.
The ICR Laboratory Consultant will use a checklist as a guide to ask questions and to
record evaluation results. The Checklist for Laboratory Approval for Giardia and
Cryptosporidium is given in Appendix C. The Checklist for Laboratory Approval for
Total Culturable Viruses is given in Appendix D. The use of a checklist provides a logical
sequence to ensure that all critical elements and recommended items related to the technical
procedures, equipment items, chemical reagents, media requirements, and associated activities
are covered. The Consultant will likely ask additional questions to ascertain the experience
and knowledge of the laboratory personnel in all these areas.
V-l
-------
Records of all method and intralaboratory QC and bench sheets must be available for
inspection. Any deficiencies noted in records or bench sheets will be included in a written
report.
Each person who must be individually approved (see Section III) will be required to
demonstrate their ability to perform the analytical protozoan or virus protocol during the
evaluation. The ICR Laboratory Consultant will also evaluate the ability of other personnel to
perform those protocol steps for which they will be responsible during the monitoring period
of the ICR. The laboratory must have sufficient reagents and materials available so that all
personnel requesting analytical approval can conduct the required assays.
The ICR Laboratory Consultant may meet with the Laboratory Director and laboratory
staff at the end of the on-site visit to present comments and recommendations on methodology,
instrumentation, sampling, sample holding times, quality assurance, or other subjects.
A formal written report of the evaluation will be forwarded to the Laboratory Director no
later than 30 days after the evaluation.
Since the ICR microanalytical program is scheduled for 18 months, only one on-site
evaluation of each laboratory will be conducted.
V-2
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SECTION VI. LABORATORY APPROVAL STATUS
The U.S. EPA Laboratory Approval Program is a limited coverage program established to
carry out the provisions of the ICR.
APPROVAL CLASSIFICATION
Laboratories, principal analysts and analysts will be classified according to the following:
Laboratories:
Approved - the laboratory meets the requirements for physical facilities and
equipment.
Not Approved - the laboratory possesses major facilities or equipment deficiencies, or
does not have an approved analyst.
Only laboratories with an "Approved" status are qualified to analyze ICR samples. It is
the water system's responsibility to ensure that only an "Approved" analytical laboratory is
used. If the U.S. EPA notifies a system that its contracted analytical laboratory's status has
been changed from "Approved" to "Not Approved," the system must take immediate steps
to find another approved laboratory.
Principal Analysts/Analysts3:
Approved - The analyst (1) demonstrates strict adherence to the ICR
analytical methods during an on-site evaluation, (2) performs
satisfactorily on QC samples and (3) successfully analyzes
unknown PE samples.
Conditionally Approved - The analyst does not perform satisfactorily on unknown PE
samples during any six month period and has not completed
analysis of the next scheduled monthly sample.
Not Approved - The analyst does not demonstrate method proficiency during
an on-site evaluation, does not perform satisfactorily on QC
samples or does not successfully analyze unknown PE sam-
ples.
3These approval categories apply to principal analysts and analysts from laboratories
performing virus analyses and to principal analysts from laboratories performing
protozoan analyses.
VI-1
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Approval of principal analysts and analysts for the ICR is laboratory-dependent. All
analysts who transfer to another laboratory lose their approval status and are not eligible to
immediately perform ICR analyses at a new laboratory. The following steps must be per-
formed before the analyst is eligible to analyze ICR samples: 1) an amended ICR Application
for Approval (see Appendix B) listing the qualifications of the analyst must be submitted by
the new laboratory and accepted by EPA, and 2) principal analysts and analysts (virus
laboratories only) must successfully analyze an unknown PE sample set at the new facility.
CRITERIA FOR CHANGING APPROVAL STATUS
The approval status of a laboratory or analyst may be changed during the ICR according
to the following criteria:
Changing Laboratory Approval Status:
It is the responsibility of analytical laboratories to notify U.S. EPA within seven days of
any change (e.g., personnel, equipment, laboratory facilities, location, etc) in ICR application
status. Failure to notify U.S. EPA of changes may result in loss of approval. If U.S. EPA
decides that a laboratory is subject to downgrading to a "Not Approved" status because of the
change, the Laboratory Director or owner will be notified in writing (by registered or
certified mail) of the proposed change of classification. The Laboratory Director or owner
will have seven days from the date of the notification to review the deficiency cited and
respond to the U.S. EPA in writing specifying what corrective actions are being taken. The
U.S. EPA will consider the adequacy of the response and notify the laboratory by mail within
seven days of its approval status.
Changing Analyst Approval Status:
The approval status of analysts using the ICR analytical methods for protozoa or total
culturable viruses will be changed based upon their performance on QC and PE samples (see
Figure VI-1)
1. PE Samples: Figure VI-2 gives the decision tree for deciding analyst approval status
based upon PE sample data.
a. An approved analyst will fail a PE sample set by submitting PE sample data that fall
outside the acceptable quantitative range for the PE lots analyzed or by submitting late PE
sample data. Data will be considered late if the data are not mailed to the U.S. EPA
within two weeks of the shipping date of the sample to the analytical laboratory for
protozoan analyzes and seven weeks for viral analyses.
VI-2
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FIGURE VI-1. ICR - MICROBIOLOGY DECISION TREE
There are two criteria for on-going evaluation of Approved Analysts:
• Successful Analysis of PE Samples and Timely Submission of Data (Criterion #1)
• Successful Analysis of QC Samples and Timely Submission of Data (Criterion #2)
Criterion #1 is monitored and evaluated via a contractor in Cincinnati, Ohio, using the
process outlined in Figure VI-2. Criterion #2 is monitored and evaluated via a contractor
associated with the main ICR public database (Data Central), using the process outlined in
Figure VI-3. The recommendations of the contractors are forwarded to U.S. EPA person-
nel in Cincinnati for review and action.
Criterion #1 Criterion #2
(See Figure VI-2) (See Figure VI-3)
\
EPA-Cincinnati
If U.S. EPA concurs with the recommendation to disapprove an analyst, the following
actions will occur:
• The laboratory and the analyst will be notified of the loss of approval status for the
method.
• Affected utilities will be notified.
b. Failure of an approved analyst to pass any six month set of PE samples will result in
the analyst's status being changed to "Conditionally Approved". The data produced by
that analyst following the failure will be flagged as questionable. If the analyst passes the
next PE sample set, the analyst's status will be converted to "Approved", and his or her
results will be accepted for ICR use.
c. If the analyst fails the next PE sample set, that analyst's status is immediately
changed to "Not Approved." All the ICR sample data reported by that analyst from the
date of analysis of the first failed PE sample to the date of the second failed PE sample
will be converted from "quantitative" to "qualitative" by changing all positive values
to "PD" and all less than detection limit values to "ND". PD indicates that pathogens
were detected under conditions where pathogen levels are likely to be higher than the
VI-3
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FIGURE VI-2. CRITERION #1 DECISION TREE
ICR PE results are sent from the analyst to Data-Cincinnati
Contact analyst
for clarification
y i
PE data are reviewed for completeness TN
Are all necessary data present? '
I
Yes
Did the analyst's reported PE
data meet the PE criteria?1
No \Yes
\^
Analyst is sent the next monthly PE Analyst complies with
sample and a letter of explanation continued approval
Data Central is notified 2 criterion # 1
I
Yes
Did the analyst's reported PE
data meet the PE criteria?1
\
No
Analyst is disapproved
\
Data Central is notified to convert data3
1 Analysts do not meet PE criteria when their PE data fall outside the acceptable quantitative
range for any PE sample set analyzed or if they do not report PE data to Data-Cincinnati
within seven weeks for virus data and two weeks for protozoan data.
2Data Central will flag all data produced by an analyst since the ending date of the failed PE
sample set as questionable and will convert the approval status of the analyst to "Condition-
ally Approved."
3Data Central will convert data received from the ending date of the 1st PE sample set to the
ending date of the 2nd PE sample set from "quantitative" to "qualitative" by changing all
positive values to "PD" and all less than detection limits to "NP." All data received after the
ending date of the 2nd PE sample set will be deleted. The approval status of the analyst will
be converted to "Not Approved."
VI-4
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value actually measured. ND indicates that pathogens were not detected either due to
their absence from samples or due to conditions that result in obtaining values that are less
than the detection limit. All data received after the date of analysis of the second PE
sample set will be deleted.
2. QC Samples: Figure VI-3 gives the decision tree for deciding analyst approval status
based upon QC sample data.
a. The status of an approved analyst will be changed to "Not Approved" if the analyst
obtains invalid QC data or submits late sample or QC data for three consecutive batches
during any sliding six month period. QC data will be considered invalid if a positive
value is obtained from the negative QC sample or if the observed values obtained from
positive QC samples do not fall within an acceptable range. The acceptable range will be
determined by the U.S. EPA. Protozoan QC data will be considered late if results are not
submitted on the first monthly QC data disk that is due two weeks after the latest sample
collection date within a batch. Virus QC data will be considered late if results are not
submitted on the first monthly QC data disk that is due seven weeks after the latest
sample collection date within a batch. Sample data will be considered late if U.S. EPA
does not receive data by the time specified in the final rule.
b. The status of an approved analyst will be changed to "Not Approved" if the analyst
obtains invalid QC data or submits late sample or QC data for any two batches during any
sliding six month period for an analyst analyzing a batch every three to four weeks, from
any three batches for an analyst analyzing a batch every two weeks, or from any six
batches for an analyst analyzing a batch every week.
c. Data received from the date of analysis of the first failed QC sample set to the date of
analysis of the QC sample set leading to disapproval will be converted from "quanti-
tative" to "qualitative" by changing all positive values to "PD" and all less than
detection limit values to "ND" as above. All data received after the date of analysis of
the QC sample set leading to disapproval will be deleted. The approval status of the
analyst will be converted to "Not Approved".
SYSTEM FOR NOTIFYING UTILITIES OF LABORATORY STATUS
EPA will maintain and make available a list of "Approved" laboratories. The list will be
distributed directly to participating water systems, as well as each U.S. EPA Regional Office
and State Primacy Agency. The list will also be available for public distribution from the U.S.
EPA.
VI-5
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FIGURE VI-3. CRITERION #2 DECISION TREE
ICR QC results are sent from the analyst to Data Central
Contact analyst
for clarification
QC data are reviewed for completeness
Are all necessary data present?
I Yes
Was QC data received on time?1
,Yes
No
V
Did the analyst exceed
disapproval criteria?l
No
Letter sent to analyst
requesting data
and explanation
Yes
Did the analyst's reported QC
data meet the QC criteria?1
\Yes
No Compliance with
continued approval
criteria #2
Data and explanation
received on time?
Delete batch data
Yes
'No
Did the analyst exceed
disapproval criteria?
Yes
Analyst disapproved
Convert data2
Analysts will be disapproved for any of the following conditions: invalid QC data or late
submission of data for three consecutive batches during sliding six month periods; invalid
QC data or late submission of data from any two batches during sliding six month periods
for analysts analyzing a batch every three to four weeks, from any three batches for analysts
analyzing a batch every two weeks or from any six batches for analysts analyzing a batch
every week.
2Data Central will convert data received from the date of analysis of the 1st failed QC
sample to the date of analysis of the QC sample leading to disapproval from "quantitative"
to "qualitative" by changing all positive values to "PD" and all less than detection limits to
"NP." All data received after the date of analysis of the QC sample leading to disapproval
will be deleted. The approval status of the analyst will be converted to "Not Approved."
VI-6
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SECTION VII. ICR PROTOZOAN METHOD FOR DETECTING
GIARDIA CYSTS AND CRYPTOSPORIDIUMOOCYSTS IN WATER
BY A FLUORESCENT ANTIBODY PROCEDURE
TABLE OF CONTENTS
PART 1 - SCOPE VII-4
PART 2 - TERMINOLOGY VII-4
PART 3 - SUMMARY OF TEST METHOD VII-5
PART 4 - SIGNIFICANCE AND USE VII-5
PART 5 - INTERFERENCES VII-5
PART 6 - APPARATUS VII-6
SAMPLE COLLECTION VII-6
SAMPLE PROCESSING VII-7
SAMPLE EXAMINATION VII-8
PART 7 - REAGENTS VII-8
REAGENT PURITY VII-8
REAGENT PREPARATION VII-9
Sample Collection VII-9
Sample Processing VII-9
Sample Examination VII-10
PART 8 - PRECAUTIONS VII-11
PART 9 - SAMPLING VII-11
SAMPLING APPARATUS PREPARATION AND ASSEMBLY VII-11
RAW WATER SAMPLE COLLECTION VII-12
FINISHED WATER SAMPLE COLLECTION VII-16
PART 10 - ASSAY PROCEDURE VII-17
FILTERELUTION AND CONCENTRATION VII-17
Washing By Hand VII-17
Stomacher Washing VII-18
Eluate Concentration VII-18
FLOTATION PURIFICATION VII-19
INDIRECT FLUORESCENT ANTIBODY (IFA) PROCEDURE VII-19
Determining Sample Volume per Filter (optional) VII-19
VII-1
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Preparing the Filtration Manifold VII-20
Membrane Filter Preparation VII-20
Sample Application VII-22
Indirect Fluorescent Antibody Staining VII-24
Filter Mounting VII-24
Microscopic Examination VII-25
General VII-25
IFA Controls VII-26
Negative IFA Control for Giardia/Cryptosporidium VII-26
Positive IFA Control for Giardia/Cryptosporidium VII-26
Sample Examination VII-27
Calculation VII-28
Reporting VII-31
Quality Control (QC) Samples VII-31
Negative QC Sample Preparation VII-31
Positive QC Sample Preparation VII-31
PART 11 - EDUCATION, TRAINING AND PROFICIENCY VII-32
MINIMAL PERSONNEL REQUIREMENTS VII-32
Principal Analyst/Supervisor: VII-32
Analyst VII-32
Technician VII-33
PART 12 - KEY WORDS VII-33
Appendix VII-1. CLEANING THE MANIFOLD AND WELLS VII-34
MANIFOLD VII-34
STAINLESS STEEL WELLS VII-34
Appendix VII-2. SAMPLE CALCULATION VII-35
POSITIVE SAMPLES VII-35
NEGATIVE SAMPLES VII-36
Appendix VII-3. GIARDIA REPORT FORM VII-37
Appendix VII-4. CRYPTOSPORIDIUMREPORT FORM VII-38
Appendix VII-5. MICROSCOPE ADJUSTMENTS VII-39
EPIFLUORESCENT MERCURY BULB AND TRANSMITTED LIGHT BULB
FILAMENT VII-39
Mercury Bulb Adjustment VII-39
Transmitted Bulb Adjustment VII-40
ADJUSTMENT OF INTERPUPILLARY DISTANCE AND OCULARS VII-40
VII-2
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Interpupillary Distance VII-40
Ocular Adjustment for Each Eye VII-41
For microscopes not capable of photomicrography VII-41
For microscopes capable of viewing a photographic frame VII-41
CALIBRATION OF AN OCULAR MICROMETER VII-41
KOHLER ILLUMINATION VII-43
VII-3
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PART 1 - SCOPE
1. This test method describes the detection and enumeration of Giardia cysts and Crypto-
sporidium oocysts in ground, surface, and finished waters by a fluorescent antibody procedure.
These pathogenic intestinal protozoa occur in domestic and wild animals as well as in humans.
The environment may become contaminated through direct deposit of human and animal feces
or through sewage and wastewater discharges to receiving waters. Ingestion of water
containing these organisms may cause disease.
2. Results obtained by this method should be interpreted with extreme caution. High and
low turbidity can affect the recovery efficiency of this method. Failure to detect organisms of
interest and/or a low detection limit does not ensure pathogen-free water.
3. This method does not purport to address all of the safety problems associated with its use.
It is the responsibility of the user of this method to establish appropriate safely and health
practices and determine the applicability of regulatory limitations prior to use.
PART 2 - TERMINOLOGY
DESCRIPTION OF TERMS SPECIFIC TO THIS METHOD
1. axoneme - an internal flagellar structure which occurs in some protozoa, e.g., Giardia,
Spironucleus, and Trichomonas.
2. cyst - a phase or a form of an organism produced either in response to environmental
conditions or as a normal part of the life cycle of the organism. It is characterized by a thick
and environmentally-resistant cell wall.
3. median bodies - prominent, dark-staining, paired organelles consisting of microtubules
and found in the posterior half of Giardia. In G. lamblia (from humans), these structures often
have a claw-hammer shape while in G. muris (from mice), the median bodies are round.
4. oocyst - the encysted zygote of some Sporozoa, e.g., Cryptosporidium. This is a phase or
a form of the organism produced either in response to environmental conditions or as a normal
part of the life cycle of the organism. It is characterized by a thick and environmentally-
resistant cell wall.
5. sporozoite - a motile, infective, asexual stage of certain sporozoans, e.g., Cryptospori-
dium. There are four sporozoites in each Cryptosporidium oocyst, and they are generally
banana-shaped.
VII-4
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6. Nucleus - a prominent internal structure seen both in Giardia cysts and Cryptosporidium
oocysts. Sometimes one to four nuclei can be seen in Giardia cysts. In Cryptosporidium
oocysts there is one nucleus per sporozoite.
PART 3 - SUMMARY OF TEST METHOD
Pathogenic intestinal protozoa are concentrated from a large volume of water sample by
retention on a yarn-wound filter. Retained particulates are eluted from the filter with an
eluting solution and are concentrated by centrifugation. Giardia cysts and Cryptosporidium
oocysts are separated to some extent from other particulate debris by flotation on a Percoll-
sucrose solution with a specific gravity of 1.1. A monolayer of the water layer/Percoll-sucrose
interface is placed on a membrane filter, indirectly stained with fluorescent antibody, and
examined under a microscope. Cysts and oocysts are classified according to specific criteria
(immunofluorescence, size, shape, and internal morphological characteristics), and the results
are reported in terms of the categories per 100 L. The categories used in reporting include
cysts and oocysts that are empty, that have amorphous structure, and that have internal
structure. A sum of the cysts and oocysts that fall into each of these categories is also reported
as the total IFA count.
PART 4 - SIGNIFICANCE AND USE
1. This test method will provide a quantitative indication of the level of contamination in raw
and treated drinking waters with the environmentally resistant stages of two genera of
pathogenic intestinal protozoa: Giardia and Cryptosporidium.
2. This test method will not identify the species of protozoa, it will not identify the host
species of origin, it cannot determine the viability status, nor can it determine the infectivity
status of detected cysts and oocysts.
3. This test method may be useful in determining the source or sources of contamination of
water supplies, the occurrence and distribution of protozoa in water supplies, and in evaluating
the effectiveness of treatment practices.
PART 5 - INTERFERENCES
1. Turbidity due to inorganic and organic debris and other organisms can interfere with the
concentration, purification and examination of the sample for Giardia cysts and Crypto-
sporidium oocysts.
VII-5
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2. In addition to naturally-occurring debris, e.g., clays and algae, debris may be added to
water during the treatment process, e.g., iron and alum coagulants and polymers.
3. Organisms and debris that autofluoresce or demonstrate non-specific fluorescence, e.g.,
algal and yeast cells and Spironucleus (Hexamita) sp.1, when examined by epifluorescent
microscopy could interfere with the detection of cysts and oocysts and contribute to false
positive values.
4. Chlorine compounds, and perhaps other chemicals used to disinfect or treat drinking
water and wastewater, may interfere with the visualization of internal structures ofGiardia
cysts and Cryptosporidium oocysts.
5. Freezing filter samples, eluates or concentrates could interfere with the detection and/or
identification of cysts and oocysts originally present in the sample.
PART 6 - APPARATUS
SAMPLE COLLECTION
The following sampling apparatus components are required:
1. Filter and filter holder: Either a 25.4 cm (10 in.) long 1 //m nominal porosity, yarn-wound
polypropylene cartridge Commercial honeycomb filter tube (M39R10A; Commercial Filters
Parker Hannifin Corp., P.O. Box 1300, Lebanon, IN) with a Commercial LT-10 filter holder
or a 25.4 cm (10 in.) long 1 //m nominal porosity Filterite polypropylene cartridge (Ul A10U;
Filterite Corporation, Timonium, MD), with a Filterite LMO10U-3/4 filter holder must be used.
2. Garden hose or PVC tubing and connectors.
3. Water meter
4. Fluid proportioner (or proportioning injector) for disinfected water.
5. Pressure regulator.
6. Pressure gauge(s).
7. Flow control valve, 4 L/min.
^anuschka, M.M., et al. 1988. A comparison ofGiardia microti and Spironucleus
muris cysts in the vole: an immunocytochemical, light, and electron microscopic study. J.
Parasitol. 74(3):452-458.
VII-6
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8. Pump, electric or gasoline powered, for sampling unpressurized water sources.
9. Plastic sample bags, double-track, zipper-lock or equivalent, approximately 15 in. (38 cm)
x 15 in (38 cm).
10. Ice chest or cooler.
11. Cold packs or wet ice.
12. Latex gloves.
SAMPLE PROCESSING
The following apparatus components are required for sample processing:
1. Pans or trays, stainless steel or glass trays, approx. 16.5 in. (41.91 cm) x 10 in. (25.4 cm)
x 2 in. (5.08 cm) deep.
2. Knife/cutting tool, for cutting the polypropylene filter fibers off filter core.
3. Hydrometer, for liquids heavier than water (range: 1.000-1.225), for adjusting specific
gravity of flotation solutions.
4. Centrifuge, with swinging bucket rotors having a capacity of 15 to 250 mL or larger per
conical tube or bottle.
5. Mixer, vortexer.
6. Vacuum source.
7. Membrane filter holder, Hoefer manifold, model FH 225V2, 10 place holder for 25 mm
diameter filters.
8. Slide warming tray, or incubator, 37°C±3°C.
9. pH meter.
10. Rubber policeman.
2Hoefer Scientific Instruments, 654 Minnesota Street, Box 77387, San Francisco,
California 94107
VII-7
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11. Stomacher Lab Blender, model 3500 (B A 7022)3 (optional). The stomacher must either
be equipped with a door (Tekmar cat. # 10-0770-000) and clamp strip (Tekmar cat. # 10-0771-
000) or have had the paddles adjusted so all the filter fibers can be extracted at one time
without stalling the instrument.
SAMPLE EXAMINATION
1. Slides, glass microscope, 1 in. (2.54 cm.) x 3 in. (7.62 cm) or 2 in. (5.08 cm.) x 3 in. (7.62
cm.).
2. Cover slips, 25 mm2, No. \1A.
3. Filters, Sartorius brand4 cellulose acetate, 0.2 jim pore size, 25 mm diameter.
4. Support Filters, ethanol-compatible membrane, any pore size, 25 mm.
5. Fingernail polish, clear or clear fixative (Cat. # 60-4890; PGC Scientifics5).
6. Splinter forceps, fine tip.
7. Blunt-end filter forceps.
8. A microscope, capable of epifluorescence and differential interference contrast (D.I.C.) or
Hoffman modulation® optics, with stage and ocular micrometers and 20X (N. A. = 0.4) to
100X (N.A. = 1.3) objectives is required for sample examination. Equip the microscope with
appropriate excitation and band pass filters for examining fluorescein isothiocyanate-labeled
specimens (exciter filter: 450-490 nm; dichroic beam-splitting mirror: 510 nm; barrier or
suppression filter: 515-520 nm).
PART 7 - REAGENTS
REAGENT PURITY
1. Purity of Reagents - Reagent grade chemicals shall be used in all tests. Unless otherwise
indicated, it is intended that all reagents shall conform to the specifications of the com-
mittee on Analytical Reagents of the American Chemical Society where such specifica-
3Tekmar Company, P.O. Box 371856, Cincinnati, Ohio 45222-1856
4Sartorius Corp., Filter Div., 30940 San Clemente, Hayward, CA 94544
5PGC Scientifics, P.O. Box 7277, Gaithersburg, Maryland 20898-7277
VII-8
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tions are available6.
2. Purity of Water - Use reagent grade deionized or double distilled water (see Table IV-1).
REAGENT PREPARATION
Prepare reagents as specified by the formulations.
Sample Collection:
1. Sodium Thiosulfate Solution (2.0 %) - Dissolve 2.0 g of sodium thiosulfate (Na^Oj •
5H2O) in 50 mL water and then adjust to a final volume of 100 mL.
Sample Processing:
1. Neutral Buffered Formalin Solution (10 %) - Dissolve 0.762 g disodium hydrogen
phosphate (Na2HPO4), 0.019 g sodium dihydrogen phosphate (NaH2PO4), and 100 mL
formalin in water to a final volume of 1 L.
2. Phosphate Buffered Saline (PBS) - Prepare a 10X stock solution by dissolving 80 g
sodium chloride (NaCl), 2 g potassium dihydrogen phosphate (KH2PO4), 29 g hydrated
disodium hydrogen phosphate (Na2HPO4 • 12H2O) and 2 g potassium chloride (KC1) in water
to a final volume of 1 L. The 10X solution is used to prepare IX PBS by diluting one
volume of the 10X solution with 9 volumes of water and adjust the pH with a pH meter to 7.4
with 0.1 N HC1 or 0.1 N NaOH before use.
3. Sodium Dodecyl Sulfate Stock Solution (1%) - Prepare solution by dissolving 1.0 g of
sodium dodecyl sulfate (SDS) in water to a final volume of 100 mL.
4. Tween 80 Stock Solution (1 %) - Mix 1.0 mL of polyoxyethylenesorbitan monooleate 80
(Tween 80) stock solution with 99 mL of water.
5. Eluting Solution (Buffered Detergent Solution) - Prepare solution by mixing 100 mL 1%
SDS, 100 mL 1% Tween 80, 100 mL 10X PBS, and 0.1 mL Sigma Antifoam A (Cat. # A
5758) with 500 mL water. Adjust the pH to 7.4 using a pH meter. Adjust the final volume to
1 L with additional water. Use within one week of preparation. At least 3 L of eluting
solution will be required for each filter elution.
6Reagent Chemicals, American Chemical Society Specifications, American Chemical
Society, Washington, DC. For suggestions on the testing of reagents not listed by the
American Chemical Society, see Annular Standards for Laboratory Chemicals, BDH,
Poole, Dorset, U.K. and the United States Pharmacopeia.
VII-9
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6. Sucrose Solution (2.5 M) - Dissolve 85.58 g of sucrose in 40 mL prewarmed water, then
adjust the final volume to 100 mL with water.
7. Percoll-Sucrose Flotation Solution, Sp. Gr. 1.10 - Mix 45 mL Percoll (sp. gr. 1.13; Sigma
Cat. # P 1644), 45 mL water and 10 mL 2.5 M sucrose solution. Check the specific gravity
with a hydrometer. The specific gravity should be between 1.09 and 1.10 (do not use if less
than 1.09). Store at 4°C and use within a week. Allow to reach room temperature before use.
Sample Examination:
1. Ensys Hydrofluor-Combo kit7 for detecting Giardia cysts and Cryptosporidium oocysts
in water samples. The expiration date for the reagents is printed on the Hydrofluor-Combo kit
label. Discard the kit once the expiration date is reached. Store the kit at 2-8 °C and return it
promptly to this temperature range after each use. The labeling reagent should be protected
from exposure to light. Do not freeze any of the reagents in this kit. Diluted, unused working
reagents should be discarded after 48 hours.
2. Ethanol (95%).
3. Glycerol.
4. Ethanol/Glycerol Series - Prepare a series of solutions according to Table VII-1.
5. DABCO-Glycerol Mounting Medium (2%) - Prewarm 95 mL glycerol using a magnetic
stir bar on a heating stir plate. Add 2 g 1,4 diazabicyclo [2.2.2] octane (DABCO, Sigma Cat. #
D-2522) to the warm glycerol with continuous stirring until it dissolves. (CAUTION:
hygroscopic; causes burns; avoid inhalation, as well as skin and eye contact.) Adjust the final
volume to 100 mL with
additional glycerol. Store at
room temperature and discard
after 6 months.
6. Bovine Serum Albumin
(1%) - Sprinkle 1.0 g bovine se-
rum albumin (BSA) crystals over
85 mL IX PBS, pH 7.4. Allow
crystals to fall before stirring into
solution with a magnetic stir bar.
After the BSA is dissolved, ad-
just the volume to 100 mL with
Table VII-1. Ethanol/Glycerol Series
95%
Ethanol
10 mL
20 mL
40 mL
80 mL
95 mL
Glycerol
5mL
5mL
5mL
5mL
5mL
Reagent
Water
80 mL
70 mL
50 mL
10 mL
OmL
Final
Volume
95 mL
95 mL
95 mL
95 mL
lOOmL
Final %
Ethanol
10
20
40
80
90.2
7Ensys Environmental Products, Inc., P.O. Box 14063, Research Triangle Park, North
Carolina 27709
VII-10
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PBS. For prolonged storage, sterilize by filtering through a 0.22 //m membrane filter into a
sterile tube or bottle. Store at 4°C and discard after 6 months.
PART 8 - PRECAUTIONS
1. The analyst/technician must know and observe the normal safety procedures required in a
microbiology laboratory while preparing, using and disposing of sample concentrates,
reagents and materials and while operating sterilization equipment.
2. Do not mouth pipet in any portion of this procedure.
PART 9 - SAMPLING
SAMPLING APPARATUS PREPARATION AND ASSEMBLY
1. The sampling apparatus (see Figure VII-1) used for raw water consists of a female hose
connector, an inlet hose, pressure regulator, pressure gauge, filter holder, a 1 |im nominal
porosity filter, an outlet hose, a water meter, and a 1 gal/min flow control valve or device (4
L/min). The sampling apparatus for chlorinated or other disinfectant treated waters also
includes a fluid proportioner or proportioning injector and pressure gauge on the influent side
of the filter housing (see Figure VII-2). In addition, a pump will be needed for unpressurized
sources.
2. Filter Holder
a. Thoroughly wash the filter holder with a stiff brush in hot water containing detergent,
when sampling is completed.
b. Rinse the filter holder with tap water until the soap residue is gone. Follow with a
thorough rinse in reagent water and air dry.
VII-11
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3. Attach a water-resistant label containing the following information to the filter holder:
Start Meter Reading: Turbidity:
Stop Time: Meter Reading: Turbidity:
Operator's Name: Total Volume Filtered:
Date: Sampling
4. Hoses
a. Inlet and outlet hoses for the filter holder consist of standard garden hoses and
fittings. If desired pressure, PVC tubing (l/2 inch ID., % inch O.D., 1/a inch wall) and/or
quick connects may be substituted for the standard garden hose and/or hose clamps.
b. Outlet hoses may be used repeatedly provided they are rinsed with at least 20 gal (76
L) of the water to be sampled prior to starting the sampling.
5. Pump: A pump is needed, when an unpressurized source is being sampled.
6. Fluid Proportioner or Proportioning Injector: If the water to be sampled is chlorinated or
disinfected by any other chemicals, the disinfectant must be neutralized during sample
collection. While the assay system allows detection of disinfected cysts and oocysts, exposure
to disinfectant may interfere with the visualization of internal morphologies of these organ-
isms. Use the sodium thiosulfate solution to neutralize the disinfectant in water samples. Add
the sodium thiosulfate solution to the water during sample collection with a mechanical fluid
proportioner pump or an in-line injector at a rate of 10 mL/gal of water sampled.8
RAW WATER SAMPLE COLLECTION
Step 1. Put on a pair of the latex gloves.
Step 2. Before connecting the sampling apparatus (see Figure VII-1) to the tap or source to
be sampled, turn on the tap and allow the water to purge residual debris from the line for 2-3
min, or until the turbidity of the water becomes uniform.
8Details on the operation and use of proportioner pumps and injectors can be found
in: Virus concentration from large sample volumes by adsorption to and elution from
microporous filters, Section 95IOC, pp. 9-92 to 9-95. In A.E. Greenberg, L.S. Clesceri and
A.D. Eaton, ed., Standard Methods for the Examination of Water and Wastewater. 19th
ed., 1995. American Public Health Association, Washington, D.C. It is not necessary to
determine that chlorine is absent from the effluent because thiosulfate is added in excess.
VII-12
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pressure gauge
7
pressure regulator
inlet hose
quick connects \
WATER SOURCE
fpt/mp optional at these points)
Figure VII-L
Row Water Sampling Apparatus
effluent hose
filter
holder
flow control valve
/L
-------
pressure regulator
\
pressure gauges
WATER SOURCE
inlet hose
| (pump optional at these points)
quick connects \
V
proportioner
(for disinfected water)
Figure VII-2
Finished Water Sampling Apparatus
flow control valve
effluent hose
7
-------
Step 3. Connect the apparatus minus the filter to the tap and allow 20 gal (76 L) to flush the
system. If a pressurized source is not available, use a pump, following the manufacturer's
instructions, to get water through the sampling apparatus. While the flushing of the apparatus
is being done, adjust the pressure regulator so the adjacent pressure gauge reads no more than
30 pounds per square inch (PSI).
Step 4. Turn off the water flow, when the flushing of the apparatus is complete. Open the
filter housing and pour all the water out. Put the filter in, close, and tighten the filter housing.
Step 5. Use a water-resistant marking pen to record the start time, meter reading, name of
person collecting the sample, turbidity, date and sampling location on the filter holder label.
Step 6. Start water flow through the filter. Check the pressure gauge after the pressure
regulator to make sure the reading is no more than 30 PSI. Readjust the regulator, if necessary.
Step 7. After the 100 L (26.4 gal) of raw water has passed through the filter, shut off the
water flow, record the stop time, final meter reading and turbidity of the water at the end of
filtration on the filter holder label.
Step 8. Disconnect the sampling apparatus while maintaining the inlet hose level above the
level of the opening on the outlet hose to prevent backwashing and the loss of paniculate
matter from the filter.
Step 9. After allowing the apparatus to drain, open the filter housing and pour the residual
water remaining in the filter holder into a plastic sample bag.
Step 10. Aseptically remove the filter from the holder and transfer the filter to the plastic
sample bag containing the residual water. Seal the bag. Do not set the bag down or allow it to
touch any environmental surface.
Step 11. Immediately place the bag inside a second plastic sample bag and then seal the
second (outer) bag. Transfer the label or label information from the filter holder to the outside
of this second (outer) bag.
Step 12. Transport the sample to the laboratory on wet ice or with, but not, on cold packs.
When the filter(s) arrive at the laboratory, they should be immediately stored at 2-5 °C. Do not
freeze the filter during transport or storage.
VII-15
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FINISHED WATER SAMPLE COLLECTION
If the water must be neutralized, add sodium thiosulfate solution via the proportioner
system. For each 100 L of finished water sampled, 250 mL of 2.0% sodium thiosulfate
solution will be needed.
Step 1. Put on a pair of the latex gloves.
Step 2. Before connecting the sampling apparatus (see Figure VII-2) to the tap or source to
be sampled, turn on the tap and allow the water to purge residual debris from the line for 2-3
min, or until the turbidity of the water becomes uniform.
Step 3. Connect the apparatus minus the filter to the tap and allow 20 gal (76 L) to flush the
system. If a pressurized source is not available, use a pump, following the manufacturer's
instructions, to get water through the sampling apparatus. While the flushing is being done
adjust the pressure regulator, so the adjacent pressure gauge reads no more than 30 PSI. Pour
the 2% sodium thiosulfate solution into a graduated cylinder. Place the injector tube into the
solution and adjust the larger top (vacuum) screw on the injector, so the pressure on the
pressure gauge following the injector reads no more than 19 PSI. Now adjust the smaller
bottom (flow) screw on the injector, so the flow rate of the thiosulfate solution is 10 mL/min.
A hose cock clamp on the injector tube may be required to achieve the correct thiosulfate flow
rate. After this adjustment is complete, transfer the injector tube to a graduated carboy of
thiosulfate solution.
Step 4. Turn off the water flow, when the flushing of the apparatus is complete. Open the
filter housing and pour all the water out. Put the filter in, close, and tighten the filter housing.
Step 5. Use a water-resistant marking pen to record the start time, meter reading, name of
person collecting the sample, turbidity, date and sampling location on the filter holder label.
Step 6. Start water flow through the filter. Check the pressure gauge after the pressure
regulator to make sure the reading is no more than 30 PSI. Also check to make sure the
thiosulfate solution is being drawn into the sampling apparatus. Readjust the regulator and
injector, if necessary.
Step 7. After the 1,000 L (264.2 gal) of finished water has passed through the filter, shut off
the water flow, record the stop time, final meter reading and turbidity of the water at the end of
filtration on the filter holder label.
Step 8. Disconnect the sampling apparatus while maintaining the inlet hose level above the
level of the opening on the outlet hose to prevent backwashing and the loss of paniculate
matter from the filter.
VII-16
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Step 9. After allowing the apparatus to drain, open the filter housing and pour the residual
water remaining in the filter holder into a plastic sample bag.
Step 10. Aseptically remove the filter from the holder and transfer the filter to the plastic
sample bag containing the residual water. Seal the bag. Do not set the bag down or allow it to
touch any environmental surface.
Step 11. Immediately place the bag inside a second plastic sample bag and then seal the
second (outer) bag. Transfer the label or label information from the filter holder to the outside
of this second (outer) bag.
Step 12. Transport the sample to the laboratory on wet ice or with but not on cold packs and
refrigerate at 2-5 °C. Do not freeze the filter during transport or storage.
PART 10 - ASSAY PROCEDURE
FILTER ELUTION AND CONCENTRATION
The initiation of sample collection and elution from the collection filter must be performed
within 96 hrs. Two approaches to eluting the particulates from the filter may be used: either
washing by hand or using a stomacher.
Washing By Hand:
Step 1. Remove the filter from the inner bag and place it in a glass or stainless steel tray.
Pour the residual solution in either the inner or outer bags into a pooling beaker, rinse the bags
with eluting solution, add the rinse solution to the beaker and discard the bags.
Step 2. Using a razor knife or other appropriate disposable cutting instrument, cut the filter
fibers lengthwise down to the core. Discard the blade, after the fibers have been cut. Divide
the filter fibers into a minimum of six equal portions with one-sixth consisting of those
cleanest fibers nearest the core; the second one-sixth being the second layer of fibers, and so
on until the final one-sixth consisting of the outer-most filter fibers (the dirtiest fibers).
Step 3. Beginning with the cleanest fibers (the one-sixth nearest the core), hand wash the
fibers in three consecutive 1.0 L volumes of eluting solution. Wash the fibers by kneading
them in the eluting solution contained either in a beaker or a plastic bag. Wring the fibers to
express as much of the liquid as possible before discarding. Maintain the three 1.0 L volumes
of eluate separate throughout the washing procedure. An additional beaker or two with clean
eluting solution may be required for extremely dirty filters.
VII-17
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Step 4. Using the three 1.0 L volumes of eluate from Step 3, repeat the washing procedure
on the second one-sixth layer of fibers, and then continue sequentially with the remaining one-
sixth layers of fibers.
Step 5. The minimum total wash time of fibers should be 30 min. After all the fibers have
been washed, combine the three 1.0 L volumes of eluate with the residual filter water in the
pooling beaker from Step 1. Discard the fibers.
Stomacher Washing:
Step 1. Use a stomacher with a bag capacity of 3500 mL. Remove the filter from the inner
bag and place it in a glass or stainless steel tray. Pour the residual solution in either the inner or
outer bags into a pooling beaker, rinse the bags with eluting solution, add the rinse solution to
the beaker and discard the bags. Using a razor knife or other appropriate disposable cutting
instrument, cut the filter fibers lengthwise down to the core. Discard the blade, after the fibers
have been cut.
Step 2. After loosening the fibers, place all the filter fibers in a stomacher bag. To insure
against bag breakage and sample loss, place the filter fibers in the first stomacher bag into a
second stomacher bag.
Step 3. Add 1.75 L of eluting solution to the fibers. Homogenize for 2-five minute intervals.
Between each homogenization period, hand knead the filter material to redistribute the fibers
in the bag.
Step 4. Pour the eluted particulate suspension into a 4 L pooling beaker. Wring the fibers to
express as much of the liquid as possible into the pooling beaker.
Step 5. Put the fibers back into the stomacher bag, add 1.0 L more eluting solution, and
homogenize, as in Step 3 above, for 2-five minute intervals. Between each homogenization
period, hand knead the filter material to redistribute the fibers in the bag.
Step 6. Add the eluted particulate suspension to the 4 L pooling beaker. Wring the fibers to
express as much of the liquid as possible into the pooling beaker. Discard the fibers. Rinse the
stomacher bag with eluting solution and place this rinse water into the pooling beaker.
Eluate Concentration:
Concentrate the combined eluate and residual water into a single pellet by centrifugation
at 1,050 xg for 10 min using a swinging bucket rotor and plastic conical centrifuge bottles.
Carefully aspirate and discard the supernatant fluid and resuspend the pellet in sufficient
elution solution by vortexing. After pooling the particulates in one conical bottle, centrifuge
once more at 1,050 xg for 10 min and record the packed pellet volume. Carefully aspirate and
VII-18
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discard the supernatant fluid and resuspend the pellet by vortexing in an equal volume of 10%
neutral buffered formalin solution. If the packed pellet volume is less than 0.5 mL, bring the
pellet and solution volume to 0.5 mL with eluting solution before adding enough 10%
buffered formalin solution to bring the resuspended pellet volume to 1.0 mL.
At this point, a break may be inserted if the procedure is not going to progress immedi-
ately to the FLOTATION PURIFICATION procedure below. If a break is inserted at this
point, be sure to store the formalin treated sample at 4°C for not more than 72 hours.
FLOTATION PURIFICATION
Step 1. In a clear plastic 50 mL conical centrifuge tube(s), vortex a volume of resuspended
pellet equivalent to not more than 0.5 mL of packed pellet volume with a sufficient volume of
eluting solution to make a final volume of 20 mL.
Step 2. Using a 50 mL syringe and 14 gauge cannula, underlay the 20 mL vortexed suspen-
sion of particulates with 30 mL Percoll-sucrose flotation solution (sp. gr. 1.10).
Step 3. Without disturbing the pellet suspension/Percoll-sucrose interface, centrifuge the
preparation at 1,050 xg for 10 min using a swinging bucket rotor. Slowly accelerate the centri-
fuge over a 30-sec interval up to the speed where the tubes are horizontal to avoid disrupting
the interface. Similarly, at the end of centrifugation, decelerate slowly. DO NOT USE THE
BRAKE.
Step 4. Using a polystyrene 25 mL pipet rinsed with eluting solution, draw off the top 20 mL
paniculate suspension layer, the interface, and 5 mL of the Percoll-sucrose below the interface.
Place all these volumes in a plastic 50 mL conical centrifuge tube.
Step 5. Add additional eluting solution to the plastic conical centrifuge tube (Step 4) to a
final volume of 50 mL. Centrifuge at 1,050 xg for 10 min.
Step 6. Aspirate and discard the supernatant fluid down to 5 mL (plus pellet). Resuspend the
pellet by vortexing and save this suspension for further processing with fluorescent antibody
reagents.
INDIRECT FLUORESCENT ANTIBODY OFA^ PROCEDURE
Determining Sample Volume per Filter (optional):
Step 1. Determine the volume of sample concentrate from the Flotation Purification
procedure above that may be applied to each 25-mm diameter membrane filter used in the IFA
assay.
VII-19
-------
Step 2. Vortex the sample concentrate and apply 40 jiL to one 5-mm diameter well of a 12-
well red heavy teflon-coated slide9.
Step 3. Allow the sample to sit approximately two min at room temperature.
Step 4. Examine the flooded well at 200X total magnification. If the particulates are
distributed evenly over the well surface area and are not crowded or touching, then apply 1 mL
of the undiluted sample to a 25-mm diameter membrane filter in Step 6 of Sample Applica-
tion below.
Step 5. Adjust the volume of the sample accordingly if the particulates are too dense or are
widely spread. Retest on another well. Always adjust the sample concentrate volume so that
the density of the particulates is just a little sparse. If the layer of sample particulates on the
membrane filters is too dense, any cysts or oocysts present in the sample may be obscured
during microscopic examination. Make sure the dilution factor, if any, from this Step is
recorded.
Preparing the Filtration Manifold:
Step 1. See Figure VII-3 for a diagram of the filtration manifold assembly.
Step 2. Connect the filtration manifold to the vacuum supply using a vacuum tube containing
a "T"-shaped tubing connector. Attach a Hoffman screw clamp to 4-6 cm of latex tubing and
then attach the latex tubing to the stem of the "T" connector. The screw clamp is used as a
bleeder valve to regulate the vacuum to 2-4 inches (5-10 cm) of Hg.
Step 3. Close all the manifold valves and open the vacuum all the way. Using the bleeder
valve on the vacuum tubing, adjust the applied vacuum to 2-4 inches (5-10 cm) of Hg. Once
adjusted, do not readjust the bleeder valve during filtration. If necessary, turn the vacuum on
and off during filtration at the vacuum source.
Membrane Filter Preparation:
Step 1. One Sartorius 25 mm diameter cellulose acetate filter, 0.2 jim pore size and one 25-
mm diameter ethanol compatible membrane support filter, any porosity, are required for each
1 mL of adjusted suspension obtained in the Determining Sample Volume per Filter section
of Part 10. Soak the required number of each type of filter separately in Petri dishes filled
with IX PBS. Drop the filters, handling them with blunt-end filter forceps, one by one flat on
the surface of the buffer. Once the filters are wetted, push the filters under the fluid surface
with the forceps. Allow filters to soak for a minimum of one minute before use.
9Cel-line Associates, Inc., 33 Gorgo Lane, Newfield, NJ 08344, Cat. #10-111.
VII-20
-------
cylinder well
stainless steel support
screen for membrane
sample holding weight
vacuum gauge
teflon valve
connection for vacuum
source (main)
drain spout
screw clamp acting
as bleeder valve
PVC collection box
drainage port
(to vacuum source)
Figure VII-3.
Ten-Place Manifold with Stainless Steel Wells (Hoefer Model FH 255V)
-------
Step 2. Turn the filtration manifold vacuum source on. Leaving all the manifold well
support valves closed, place one support filter on each manifold support screen. This filter
ensures even distribution of sample.
Step 3. Place one Sartorius 25-mm diameter cellulose acetate filter on top of each support
filter. Use a rubber policeman to adjust the cellulose acetate filter, if necessary. Open the
manifold well support valves to flatten the filter membranes. Make sure that no bubbles are
trapped and that there are no creases or wrinkles on any of the filter membranes.
Step 4. Use as many filter positions as there are sample volumes to be assayed. Record the
number of sample 25-mm membrane filters prepared and the volume of floated pellet (either
determined from the optional Determining Sample Volume per Filter step or determined by
the discretion of the principal analyst) represented by these membranes. In addition, include at
least one positive control for Giardia cysts and Cryptosporidium oocysts and one negative
control each time the manifold is used.
Step 5. Position the 1 Ib (454 g) stainless steel wells firmly over each filter.
Step 6. Label each sample and control well appropriately with little pieces of tape on the top
of the stainless steel wells and/or use manifold membrane labeling diagram (Figure VII-4) to
keep track of each sample and control.
Sample Application:
Step 1. Open the manifold support valve for each well containing filters.
Step 2. Rinse the inside of each stainless steel well and membrane filter with 2 mL 1% BSA
applied with a Pasteur pipet. Drain the BSA solution completely from the membrane.
Step 3. Close the manifold valves under each membrane filter.
Step 4. For the positive controls, add 500-1000 Giardia lamblia cysts and 500-1000
Cryptosporidium parvum oocysts or use the Ensys positive control antigen as specified in the
kit to a well.
Step 5. For a negative control, add 1.0 mL IX PBS to one well.
Step 6. Add 1.0 mL of the vortexed, adjusted water sample (Determining Sample Volume
per Filter; Part 10) to a well. If the optional step to determine sample volume was not
performed, add the volume determined by the principal analyst to be appropriate to a well.
VII-22
-------
(top view)
pressure guage
1
^—*
x—-
6
2
*»•—•
1.
2.
3.
4.
5.
6.
7.
8.
9.
10,
Figure VII-4.
Ten-Place Hoefer Manifold Membrane Labeling Diagram
-------
Step 7. Open the manifold valve under each membrane filter to drain the wells. Rinse each
stainless steel well with 2 mL 1% BSA. Do not touch the pipet to the membrane filter or to the
well. Close the manifold valve under each membrane filter.
Indirect Fluorescent Antibody Staining:
Step 1. Dilute the primary antibody mixture and labeling reagent according to the manufac-
turer's instructions using IX PBS.
Step 2. Pipet 1.0 mL of the diluted primary antibody onto each membrane and allow to
remain in contact with the filter for 25 min at room temperature.
Step 3. At the end of the contact period, open the manifold valve to drain the antisera.
Step 4. Rinse each well and filter 5 times with 2 mL IX PBS. Do not touch the tip of the
pipet to the membrane filter or to the stainless steel wells. Close all manifold valves after the
last wash is completed.
Step 5. Pipet 1.0 mL labeling reagent onto each membrane and allow to remain in contact
with the filter for 25 min at room temperature. Cover all wells with aluminum foil to shield the
reagents from light and to prevent dehydration and crystallization of the fluorescein
isothiocyanate dye during the contact period.
Step 6. At this point, start the Filter Mounting procedure below.
Step 7. At the end of the contact period, open the manifold valves to drain the labeling
reagent.
Step 8. Rinse each well and filter 5 times with 2 mL IX PBS. Do not touch the tip of the
pipet to the membrane filter or to the stainless steel wells. Close all manifold valves after the
last wash is completed.
Step 9. Dehydrate the membrane filters in each well by sequentially applying 1.0 mL of 10,
20, 40, 80 and 95% ethanol solutions containing 5% glycerol. Allow each solution to drain
thoroughly before applying the next in the series.
Filter Mounting:
Step 1. Label glass slides for each filter and place them on a slide warmer or in an incubator
calibrated to 37°C.
Step 2. Add 75 jiL 2% DABCO-glycerol mounting medium to each slide on the slide
warmer or in the incubator and allow to warm for 20-30 min.
VII-24
-------
Step 3. Remove the top cellulose acetate filter with fine-tip forceps and layer it over the
correspondingly labeled DABCO-glycerol mounting medium prepared slide. Make sure the
sample application side is up. If the entire filter is not wetted by the DABCO-glycerol
mounting medium, pick up the membrane filter with the same forceps and add a little more
DABCO-glycerol mounting medium to the slide under the filter. Place the mounted filter
either on the slide warmer or in the incubator for a clearing period of 20 min.
Step 4. Use a clean pair of forceps to handle each membrane filter. Soak used forceps in a
beaker of diluted detergent cleaning solution.
Step 5. After the 20 min clearing period, the filter should become transparent and appear
drier. After clearing, if the membrane starts to turn white, apply a small amount of DABCO-
glycerol mounting medium under the filter.
Step 6. After the 20 min clearing period, apply 20 jiL DABCO-glycerol mounting medium
to the center of each membrane filter and cover with a 25 mm x 25 mm cover glass. Tap out
air bubbles with the handle end of a pair of forceps. Wipe off excess DABCO-glycerol
mounting medium from the edge of each cover glass with a slightly moistened Kimwipe.
Step 7. Seal the edge of each cover glass to the slide with clear fingernail polish.
Step 8. Store the slides in a "dry box". A dry box can be constructed from a covered
Tupperware®-type container to which a thick layer of anhydrous calcium sulfate has been
added. Cover the desiccant with paper towels and lay the slides flat on the top of the paper
towels. Place the lid on the dry box and store at 4°C.
Step 9. Examine the slides microscopically as soon as possible but within 5 days of prepara-
tion, because they may become opaque if stored longer, and D.I.C. or Hoffman modulation®
optical examination would then no longer be possible.
Microscopic Examination:
1. General: Microscopic work by a single analyst should not exceed four hours per day nor
more than five consecutive days/week. Intermittent rest periods during the four hours per day
are encouraged.
Step 1. Remove the dry box from 4°C storage and allow it to warm to room temperature
before opening.
Step 2. Adjust the microscope to assure that the epifluorescence and Hoffman modula-
tion® or D.I.C. optics are in optimal working order. Make sure that the fluorescein
isothiocyanate cube is in place in the epifluorescent portion of the microscope (see
VII-25
-------
SAMPLE EXAMINATION in Part 6). Detailed procedures required for adjusting and
aligning the microscope are found in Appendix VII-5.
2. IFA Controls: The purpose of these IFA controls is to assure that the assay reagents are
functioning, that the assay procedures have been properly performed, and that the microscope
has been adjusted and aligned properly.
a. Negative IFA Control for Giardia/Cryptosporidium
Step 1. Using epifluorescence, scan the negative control membrane at no less than 200X
total magnification for apple-green fluorescence ofGiardia cyst and Cryptosporidium
oocyst shapes.
Step 2. If no apple-green fluorescing cyst or oocyst shapes are found, and if background
fluorescence of the membrane is very dim or non-existent, continue with examination of
the water sample slides.
If apple-green fluorescing cyst or oocyst shapes are found, discontinue examination
since possible contamination of the other slides is indicated. Clean the equipment (see
Appendix VII-1), recheck the reagents and procedure and repeat the assay using
additional aliquots of the sample.
b. Positive IFA Control for Giardia/Cryptosporidium
Step 1. Using epifluorescence, scan the positive control slide at no less than 200X total
magnification for apple-green fluorescence ofGiardia cyst and Cryptosporidium oocyst
shapes. Background fluorescence of the membrane should be either very dim or non-
existent. Cryptosporidium oocysts may or may not show evidence of oocyst wall folding,
which is characterized under epifluorescence by greater concentrations of FITC along
surface fold lines, depending upon the manner in which the oocysts have been treated and
the amount of turgidity they have been able to maintain10.
If no apple-green fluorescing Giardia cyst or Cryptosporidium oocyst shapes are
observed, then the fluorescent staining did not work or the positive control cyst prepara-
tion was faulty. Do not examine the water sample slides for Giardia cysts and Cryptospo-
ridium oocysts. Recheck reagents and procedures to determine the problem.
10Robertson, L.J., et al. 1993. Induction of folds or sutures on the walls of
Cryptosporidium parvum oocysts and their importance as a diagnostic feature. Appl.
Environ. Microbiol. 59(8):2638-2641.
VII-26
-------
Step 2. If apple-green fluorescing cyst and oocyst shapes are observed, change the
microscope from epifluorescence to the 100X oil immersion Hoffman modulation® or
differential interference contrast objective.
At no less than 1000X total oil immersion magnification, examine Giardia cyst
shapes and Cryptosporidium oocyst shapes for internal morphology.
The Giardia cyst internal morphological characteristics include one to four nuclei,
axonemes, and median bodies. Giardia cysts should be measured to the nearest 0.5 //m
with a calibrated ocular micrometer. Record the length and width of cysts. Also record
the morphological characteristics observed. Continue until at least 3 Giardia cysts have
been detected and measured in this manner.
The Cryptosporidium oocyst internal morphological characteristics include one to
four sporozoites. Examine the Cryptosporidium oocyst shapes for sporozoites and
measure the oocyst diameter to the nearest 0.5 jim with a calibrated ocular micrometer.
Record the size of the oocysts. Also record the number, if any, of the sporozoites
observed. Sometimes a single nucleus is observed per sporozoite. Continue until at least
3 oocysts have been detected and measured in this manner.
3. Sample Examination
Scanning Technique - Scan each slide in a systematic fashion beginning with one edge of
the mount and covering the entire coverslip. An up-and-down or a side-to-side scanning
pattern may be used. See Figure VII-5 for an illustration of two alternatives for systematic
slide scanning.
Step 1. Empty Counts, Counts with Amorphous Structure, Counts with Internal
Structure, and Total IFA Count
a. When appropriate responses have been obtained for the positive and negative
controls, use epifluorescence to scan the entire coverslip from each sample at not less
than 200X total magnification for apple-green fluorescence of cyst and oocyst
shapes.
b. When brilliant apple-green fluorescing round to oval objects (8 to 18 jim long
by 5 to 15 |im wide) are observed with brightly highlighted edges, switch the
microscope to either Hoffman modulation® or D.I.C. optics. Look for external or
internal morphological characteristics atypical of Giardia cysts (e.g., spikes, stalks,
appendages, pores, one or two large nuclei filling the cell, red fluorescing chloro-
plasts, crystals, spores, etc.). If these atypical structures are not observed, then
categorize such apple-green fluorescing objects of the aforementioned size and shape
as either empty Giardia cysts, Giardia cysts with amorphous structure, or Giardia
VII-27
-------
cysts with internal structures (nuclei, axonemes, and median bodies). Record the
shape and measurements (to the nearest 0.5 jim at 1000X total magnification) for
each such object. Record the internal structures observed. Giardia cysts with
internal structures must be confirmed by a senior analyst. Sum the counts of empty
Giardia cysts, Giardia cysts with amorphous structure, and Giardia cysts with
internal structures. Report this sum as the total Giardia IFA count on a Giardia
Report Form (see Appendix VII-3).
c. When brilliant apple-green fluorescing ovoid or spherical objects (3 to 7 jim in
diameter) are observed with brightly highlighted edges, switch the microscope to
either Hoffman modulation® or D.I.C. optics. Look for external or internal morpho-
logical characteristics atypical of Cryptosporidium oocysts (e.g., spikes, stalks,
appendages, pores, one or two large nuclei filling the cell, red fluorescing chloro-
plasts, crystals, spores, etc.). If these atypical structures are not observed, then
categorize such apple-green fluorescing objects of the aforementioned size and shape
as either empty Cryptosporidium oocysts, Cryptosporidium oocysts with amorphous
structure, or Cryptosporidium oocysts with internal structure (one to four sporozo-
ites/oocyst). Record the shape and measurements (to the nearest 0.5 jim at 1000X
total magnification) for each such object. Although not a defining characteristic,
surface oocyst folds may be observed in some specimens. Record the number of
sporozoites observed. Cryptosporidium oocysts with sporozoites must be confirmed
by a senior analyst. Sum the counts of empty Cryptosporidium oocysts, Cryptospor-
idium oocysts with amorphous structure, and Cryptosporidium oocysts with internal
structure. Report this sum as the total Cryptosporidium IFA count on a Crypto-
sporidium Report Form (see Appendix ¥11-4).
Calculation:
Step 1. Percentage of Floated Sample Examined - Record the percentage of floated sediment
examined microscopically. [Calculate this value from the total volume of floated pellet
obtained (Part 10, FILTER ELUTION). the number of 25-mm membrane filters prepared
together with the volume of floated pellet represented by these membrane filters (Part 10,
Determining Sample Volume per Filter), and the number of membrane filters examined.]
The following values are used in calculations:
V = volume (liters) of original water sample TPart 9. RAW WATER SAMPLE
COLLECTION and FINISHED WATER SAMPLE COLLECTIONS
P = eluate packed pellet volume (Part 10, FILTER ELUTION1 (mL),
VII-28
-------
±1
Figure VII-5.
Methods for Scanning Water Filter Membrane Mounted on a Glass Slide
-------
F = fraction of eluate packed pellet volume (P) subjected to flotation (Part 10,
FLOTATION PURIFICATION. Steps 1-6), determined as
_ mL P subjected to flotation
R = Percentage (expressed as a decimal) of floated sediment examined (Part 10,
Calculation, Step 1)
TG = Total Giardia IF A cyst count (Part 10, Microscopic Examination, Section 3,
Step 1. Empty Count, Count with Amorphous Structure, and Count with Internal
Structure, and Total IFA Count, paragraph b)
EG = Count of Giardia cysts which are empty
AG = Count of Giardia cysts with amorphous internal structure
GW IS = Count of Giardia cysts with one internal structure
GW2S = Count of Giardia cysts with more than one internal structure
TC = Total Cryptosporidium IFA oocyst count
EC = Count of Cryptosporidium oocysts which are empty
AC = Count of Cryptosporidium oocysts with amorphous internal structure
CWS = Count of Cryptosporidium oocysts with internal structure
Step 2. For positive samples, calculate the number of cysts or oocysts per 1 00 L of sample as
follows:
X _ (TG, EG, AG, GW1S, GW2S, TC, EC, AC, or CfFS)(100)
100L FVR
A sample calculation is shown in Appendix VII-2.
Step 3. For samples in which no cysts or oocysts are detected, (TG or TC or GWS or CWS)
= <1. Calculate the detection limit as follows:
-------
A sample calculation is shown in Appendix VII-2.
Reporting:
Step 1. Report Giardia results as empty Giardia cysts, Giardia cysts with amorphous
structure, Giardia cysts with one internal structure, and/or Giardia cysts with two or more
internal structures, and total Giardia IF A count per 100 L of sample. Report Cryptosporidium
results as empty Cryptosporidium oocysts, Cryptosporidium oocysts with amorphous structure,
and/or Cryptosporidium oocysts with internal structure and total Cryptosporidium IFA count
per 100 L of sample. Report negative results in terms of the detection limit. Representative
reporting forms are given in Appendix VII-3 and Appendix ¥11-4.
Step 2. Enter all data into the computer spreadsheet provided with this protocol.
Quality Control (QC) Samples:
1. Negative QC Sample Preparation - This control is a check on equipment, materials,
reagents and technique. It involves processing a 1 |im nominal porosity cartridge filter as if it
were an unknown. All samples analyzed over the course of a week are considered to be a
batch. For each batch, there must be a negative QC Sample.
Step 1. Process a 1 |im nominal porosity cartridge filter for Giardia cysts and
Cryptosporidium oocysts using the FILTER ELUTION AND CONCENTRATION.
FLOTATION PURIFICATION and INDIRECT FLUORESCENT ANTIBODY proce-
dures.
Step 2. Examine the entire concentrate from this sample using the Microscopic
Examination section. If any cysts or oocysts are detected, do not process any more
unknown samples until the source of the contamination is located and corrected.
Note that the results from samples in a batch associated with finding a positive in a
negative control will be excluded from the ICR Data Base.
2. Positive QC Sample Preparation - The purpose of this control is to assure that the
laboratory can recover cysts and oocysts when they are spiked into a sample at a known level.
All samples analyzed over the course of a week are considered a batch. For each batch, there
must be a positive control.
Step 1. Seed 40 L (10.6 gal) of reagent grade water with 1000 Giardia cysts and 2000
Cryptosporidium oocysts. Pass the spiked water through a 1 |im nominal porosity
cartridge filter using the procedures found in Part 9 - Sampling.
VII-31
-------
Step 2. Process the filtered water using the FILTER ELUTION AND CONCEN-
TRATION. FLOTATION PURIFICATION and INDIRECT FLUORESCENT ANTI-
BODY procedures.
Step 3. Examine the entire concentrate for Giardia cysts and Cryptosporidium oocysts
using the Microscopic Examination section. It is not necessary to identify internal
morphological characteristic using differential interference contrast microscopy. If cysts
and oocysts are not detected, do not process any more unknown samples until the reason
for not recovering cysts and oocysts is determined and corrected. Note that the results
from samples in a batch associated with not finding cysts and oocysts in a positive control
will be excluded from the ICR Data Base.
PART 11 - EDUCATION, TRAINING AND PROFICIENCY
MINIMAL PERSONNEL REQUIREMENTS
Principal Analyst/Supervisor: To be qualified for approval, a laboratory must have a
principal analyst who may also serve as a supervisor if an additional analyst(s) is to be
involved. The principal analyst/supervisor oversees the entire analyses and carries out QC
performance checks on technicians and/or other analysts. The principal analyst/supervisor
must confirm all protozoan internal structures demonstrated at the microscope by subordinates.
This person must be an experienced microbiologist with at least a B.A./B.S. degree in
microbiology or a closely related field. The principal analyst also must have at least one year
of continuous bench experience with immunofluorescent antibody (IF A) techniques and
microscopic identification and have analyzed at least 100 water and/or wastewater samples for
Giardia and/or Cryptosporidium. In addition, PE samples must be analyzed using the ICR
protozoan method and results must fall within acceptance limits. The principal analyst/super-
visor must also demonstrate acceptable performance during an on-site evaluation.
Analyst: This person(s) performs at the bench level under the supervision of a principal
analyst/supervisor and is involved in all aspects of the analysis, including preparation of
sampling equipment, filter extraction, sample processing, microscopic protozoan identification,
and data handling. Recording presence or absence of morphological characteristics may be
done by the analyst but must be confirmed by the principal analyst. The analyst must have
two years of college lecture and laboratory course work in microbiology or a closely related
field. The analyst also must have at least six months bench experience, must have at least
three months experience with IFA techniques, and must have successfully analyzed at least 50
water and/or wastewater samples for Giardia and/or Cryptosporidium. Six months of
additional bench experience in the above areas may be substituted for two years of college. In
addition, PE samples must be analyzed using the ICR protozoan method and results must fall
within acceptance limits. The analyst must also demonstrate acceptable performance during
an on-site evaluation.
VII-32
-------
Technician: This person extracts filters and processes the samples under the supervision of an
analyst, but does not perform microscopic protozoan detection and identification. The
technician must have at least three months experience in filter extraction and processing of
protozoa samples.
PART 12 - KEY WORDS
Antibody, Cryptosporidium parvum, cysts, fluorescence, Giardia, immunoassay, oocysts,
protozoa
VII-33
-------
Appendix VII-1. CLEANING THE MANIFOLD AND WELLS
MANIFOLD
Step 1. After all the membrane filters have been mounted on glass slides (Part 10, Filter
Mounting, Step 8), remove the support filters and discard them.
Step 2. Open all the manifold valves and increase the vacuum pressure to the manifold by
closing the bleeder valve associated with the vacuum tubing.
Step 3. Rinse each manifold filter support screen with 10-20 mL of 0.01% Tween 80
solution and then with 10-20 mL of water.
Step 4. Disconnect the manifold from the vacuum and wash the cover and fluid collection
box in warm detergent solution. Rinse with tap water and reagent water.
STAINLESS STEEL WELLS
Step 1. Place a cloth on the bottom of an autoclavable container which is large enough to
accommodate all 10 stainless steel wells in a single layer.
Step 2. Put the stainless steel wells top side down on the cloth. The rim on the underside of
the well is fragile. Care must be taken to avoid scratching and denting the rim.
Step 3. Add enough reagent water containing detergent to cover the stainless steel wells by
an inch or more.
Step 4. Autoclave the stainless steel container with the stainless steel wells for 15 min at 15
lb/in2 and 121 °C. Use the slow exhaust mode at the completion of the autoclave cycle. This
step does not destroy cysts and oocysts, but aids the detergent in removing them.
Step 5. Transfer the wells to a pan of hot detergent cleaning solution.
Step 6. Vigorously scrub the inside and bottom of each stainless steel well with a sponge or
brush. Note that this step is the most important part of the well cleaning procedure.
Step 7. Rinse each well with tap water followed by reagent water. Drain and air dry the
wells.
Step 8. Always check the bottom ridge of each stainless steel well for dents and scratches.
Step 9. If dents or scratches are found on the bottom of a stainless steel well, do not use it
until it is properly reground.
VII-34
-------
Appendix VII-2. SAMPLE CALCULATION
POSITIVE SAMPLES
Assume that a 100 gal (380 L) water sample was collected. The sample was eluted
resulting in 5 mL of sediment. Fifty percent (2.5 mL) of the sediment was purified by Percoll-
sucrose flotation. Forty percent of the floated material was examined microscopically. A total
of 8 empty and 3 Giardia cysts with one internal structure were found. No Cryptosporidium
oocysts were observed. Using the formula in Part 10, Calculation:
V = 380 L
P = 5mL
F = 2.5/5 = 0.5
R = 40% = 0.4
TG =11
GW1S = 3
Giardia cysts with structures _ (GW1S)(WQ)
100 L
_ (3)(100)
(0.5)(380)(0.4)
4 ;
and
Total IF A Giardia cysts _ (7U)(100)
100 L
(0.5)(380)(0.4)
14
VII-35
-------
NEGATIVE SAMPLES
Using the description for POSITIVE SAMPLES given above, no Cryptosporidium
oocysts were observed. The calculated detection limit per 100 L would be:
Total IFA Cryptosporidium oocysts _ (rC)(100)
100 L~ FVR
(0.5)(380)(0.4)
VII-36
-------
Appendix VII-3. GIARDIA REPORT FORM
Slide Prepared by:
Analyst:
Object
Located
bylFA
No.
1
2
3
4
5
6
7
8
9
10
Shape
(oval or
round)
Size
LxW
0/m)
Total
Empty
Giardia
Cysts
GO
(A)
Giardia
Cysts with
Amorphous
Structure
GO
(B)
Date Prepared:
Date Analyzed:
Giardia Cysts with Internal Structure
(C)
Morphological Characteristics
Nucleus
(#)
Median
Body
GO
# with one morph. char.
# with > one morph. char.
A. Calculated Number of Empty Giardia Cysts/100 L
B . Calculated Number of Giardia Cysts with Amorphous Structure/1 00 L
C. Calculated Number of Giardia Cysts with one Internal Structure/1 00 L
D. Calculated Number of Giardia Cysts with more than one Internal Structure/1 00 L
E. Calculated Total IF A Giardia Count /1 00 L
Axonemes
GO
Total IF A
Giardia Count
GO
(D = A+B+C)
-------
Appendix VII-4. CRYPTOSPORIDIUMREPORT FORM
Slide Prepared By:
Analyst:
Object
Located
bylFA
No.
1
2
O
4
5
6
7
8
9
10
Shape
(oval or
round)
Size
LxW
(|im)
Total
Empty
Cryptosporidium
Oocysts
GO
(A)
Cryptosporidium
Oocysts with
Amorphous
Structure
GO
(B)
Date Prepared:
Date Analyzed:
Cryptosporidium Oocysts with
Internal Structure
(C)
Morphological Characteristics
Sporozoite (#)
A. Calculated Number of Empty Cryptosporidium Oocysts/100 L
B . Calculated Number of Cryptosporidium Oocy sts with Amorphous Structure/1 00 L
C. Calculated Number of Cryptosporidium Oocysts with Internal Structure/1 00 L
D. Calculated Total IF A Cryptosporidium Count/100 L
Total IFA
Cryptosporidium
Count
GO
(D = A+B+C)
-------
Appendix VII-5. MICROSCOPE ADJUSTMENTS
11
The microscopic portion of this procedure depends upon very sophisticated optics.
Without proper alignment and adjustment of the microscope the instrument will not function at
maximal efficiency and the probability of obtaining the desired image (information) will not be
possible. Consequently, it is imperative the all portions of the microscope from the light
sources to the oculars are properly adjusted.
While microscopes from various vendors are configured somewhat differently, they all
operate on the same general physical principles. Therefore, slight deviations or adjustments
may be required to make these guidelines work for the particular instrument at hand.
EPIFLUORESCENT MERCURY BULB AND TRANSMITTED LIGHT BULB FILAMENT
ADJUSTMENT
The sole purpose of these procedures is to insure even field illumination.
Mercury Bulb Adjustment:
This section assumes that you have successfully replaced the mercury bulb in your
particular lamp socket and reconnected the lamp socket to the lamp house. These instructions
also assume the condenser has been adjusted to produce Kohler illumination. Make sure that
you have not touched any glass portion of the mercury bulb with your bare fingers while
installing it. WARNING: Never look at the ultraviolet light coming out of the mercury
lamp house or the ultraviolet light image without a barrier filter in place.
Step 1. Usually there is a diffuser lens between the lamp and the microscope which either
must be removed or swung out of the light path.
Step 2. Using a prepared microscope slide, adjust the focus so the image in the oculars is
sharply defined.
Step 3. Replace the slide with a business card or a piece of lens paper.
Step 4. Close the field diaphragm (iris diaphragm in the microscope base) so only a small
point of light is visible on the card. This dot of light tells you where the center of the field of
view is.
Step 5. Mount the mercury lamp house on the microscope without the diffuser lens in place
and turn on the mercury bulb.
Step 6. Remove the objective in the light path from the nosepiece. You should see a primary
(brighter) and secondary image (dimmer) of the mercury bulb arc on the card after focusing the
image with the appropriate adjustment.
Step 7. Using the other lamp house adjustments, adjust the primary and secondary mercury
bulb images so they are side by side (parallel to each other) with the transmitted light dot in
between them.
Step 8. Reattach the objective to the nosepiece.
nSmith, R.F. 1982. Microscopy and Photomicrography: A Practical Guide.
Appleton-Century-Crofts, New York.
VII-39
-------
Step 9. Insert the diffuser lens into the light path between the mercury lamp house and the
microscope.
Step 10. Turn off the transmitted light, remove the card from the stage, and replace it with a
slide of fluorescent material. Check the field for even fluorescent illumination. Adjustment of
the diffuser lens will most likely be required. Additional slight adjustments as in Step 6 above
may be required.
Step 11. Maintain a log of the number of hours the U. V. bulb has been used. Never use the
bulb for longer than it has been rated. Fifty watt bulbs should not be used longer than 100
hours; 100 watt bulbs should not be used longer than 200 hours.
Transmitted Bulb Adjustment:
This section assumes that you have successfully replaced the transmitted bulb in your
particular lamp socket and reconnect the lamp socket to the lamp house. Make sure that you
have not touched any glass portion of the transmitted light bulb with your bare fingers while
installing it. These instructions also assume the condenser has been adjusted to produce
Kohler illumination.
Step 1. Usually there is a diffuser lens between the lamp and the microscope which either
must be removed or swung out of the light path. Reattach the lamp house to the microscope.
Step 2. Using a prepared microscope slide and a 40X (or similar) objective, adjust the focus
so the image in the oculars is sharply defined.
Step 3. Without the ocular or Bertrand optics in place the pupil and filament image inside
can be seen at the bottom of the tube.
Step 4. Focus the lamp filament image with the appropriate adjustment on your lamp house.
Step 5. Similarly, center the lamp filament image within the pupil with the appropriate
adjustment(s) on your lamp house.
Step 6. Insert the diffuser lens into the light path between the transmitted lamp house and the
microscope.
ADJUSTMENT OF INTERPUPILLARY DISTANCE AND OCULARS FOR EACH EYE
These adjustments are necessary, so eye strain is reduced to a minimum. These adjust-
ments must be made for each individual using the microscope. This section assumes the use of
a binocular microscope.
Interpupillary Distance:
The spacing between the eyes varies from person to person and must be adjusted for each
individual using the microscope.
Step 1. Place a prepared slide on the microscope stage, turn on the transmitted light, and
focus the specimen image using the coarse and fine adjustment knobs.
Step 2. Using both hands, adjust the oculars in and out until a single circle of light is
observed while looking through the two oculars with both eyes.
VII-40
-------
Ocular Adjustment for Each Eye.:
This section assumes a focusing pcular(s). This adjustment can be made two ways,
depending upon whether or not the microscope is capable of photomicrography and whether it
is equipped with a photographic frame which can be seen through the binoculars. Precaution:
Persons with astigmatic eyes should always wear their contact lenses or glasses when using the
microscope.
1. For microscopes not capable of photomicrography. This section assumes only the right
ocular is capable of adjustment.
Step 1. Place a prepared slide on the microscope stage, turn on the transmitted light, and
focus the specimen image using the coarse and fine adjustment knobs.
Step 2. Place a card between the right ocular and eye keeping both eyes open. Using
the fine adjustment, focus the image for the left eye to its sharpest point.
Step 3. Now transfer the card to between the left eye and ocular. Keeping both eyes
open, bring the image for the right eye into sharp focus by adjusting the ocular
collar at the top of the ocular, without touching the coarse or fine adjustment.
2. For microscopes capable of viewing a photographic frame through the viewing binocu-
lars. This section assumes both oculars are adjustable.
Step 1. Place a prepared slide on the microscope stage, turn on the transmitted light, and
focus the specimen image using the coarse and fine adjustment knobs.
Step 2. After activating the photographic frame, place a card between the right ocular
and eye keeping both eyes open. Using the correction (focusing) collar on the
left ocular focus the left ocular until the double lines in the center of the frame
are as sharply focused as possible.
Step 3. Now transfer the card to between the left eye and ocular. Again keeping both
eyes open, bring the image of the double lines in the center of the photographic
frame into as sharp a focus for the right eye as possible by adjusting the ocular
correction (focusing) collar at the top of the right ocular.
CALIBRATION OF AN OCULAR MICROMETER
12
This section assumes that an ocular reticle has been installed in one of the oculars by a
microscopy specialist and that a stage micrometer is available for calibrating the ocular
micrometer (reticle). Once installed the ocular reticle should be left in place. The more an
ocular is manipulated the greater the probability is for it to become contaminated with dust
particles. This calibration should be done for each objective in use on the microscope. If there
12Melvin, D.M. and M.M. Brooke. 1982. Laboratory Procedures for the Diagnosis of
Intestinal Parasites. U.S. Department of Health and Human Services, HHS Publication
No. (CDC) 82-8282.
VII-41
-------
is an optivar13 on the microscope, then the calibration procedure must be done for the respec-
tive objective at each optivar setting.
Step 1. Place the stage micrometer on the microscope stage, turn on the transmitted light, and
focus the micrometer image using the coarse and fine adjustment knobs for the objective to be
calibrated. Continue adjusting the focus on the stage micrometer so you can distinguish
between the large (0.1 mm) and the small (0.01 mm) divisions.
Step 2. Adjust the stage and ocular with the micrometer so the 0 line on the ocular microme-
ter is exactly superimposed on the 0 line on the stage micrometer.
Step 3. Without changing the stage adjustment, find a point as distant as possible from the
two 0 lines where two other lines are exactly superimposed.
Step 4. Determine the number of ocular micrometer spaces as well as the number of
millimeters on the stage micrometer between the two points of superimposition.
For example: Suppose 48 ocular micrometer spaces equal 0.6 mm.
Step 5. Calculate the number of mm/ocular micrometer space.
For example:
0.6 mm 0.0125 mm
48 ocular micrometer spaces ocular micrometer space
Step 6. Since most measurements of microorganisms are given in //m rather than mm, the
value calculated above must be converted to //m by multiplying it by 1000 //m/mm.
For example:
0.0125 mm 1,000 \im _ 12.5 \un
X
Ocular Micrometer Space mm Ocular Micrometer Space
Step 7. Follow Steps 1 through 6 for each objective. It is helpful to record this information
in a tabular format, like the example below, which can be kept near the microscope.
13A device between the objectives and the oculars that is capable of adjusting the total
magnification.
VII-42
-------
Item
#
1
2
3
4
Obj.
Power
10X
20X
40X
100X
Description
N.A.C =
N.A. =
N.A. =
N.A. =
No. of
Ocular
Microm.
Spaces
No. of
Stage
Microm.
mma
//m/Ocular
Micrometer
Space"
a 1000//m/mm
b (Stage Micrometer length in mm x (1,000 //m/mm)) + No. Ocular Micrometer Spaces
c N.A. stands for numerical aperture. The numerical aperture value is engraved on the
barrel of the objective.
KOHLER ILLUMINATION
This section assumes that Kohler illumination will be established for only the 100X oil
D.I.C. or Hoffman modulation® objective which will be used to identify internal morphologi-
cal characteristics in Giardia cysts and Cryptosporidium oocysts. If by chance more than one
objective is to be used for either D.I.C. or Hoffman modulation® optics, then each time the
objective is changed, Kohler illumination must be reestablished for the new objective lens.
Previous sections have adjusted oculars and light sources. This section aligns and focuses the
light going through the condenser underneath the stage at the specimen to be observed. If
Kohler illumination is not properly established, then D.I.C. or Hoffman modulation® optics
will not work to their maximal potential. These Steps need to become second nature and must
be practiced regularly until they are a matter of reflex rather than a chore.
Step 1. Place a prepared slide on the microscope stage, place oil on the slide, move the 100X
oil objective into place, turn on the transmitted light, and focus the specimen image using the
coarse and fine adjustment knobs.
Step 2. At this point both the radiant field diaphragm in the microscope base and the
aperture diaphragm in the condenser should be wide open. Now close down the radiant field
diaphragm in the microscope base until the lighted field is reduced to a small opening.
Step 3. Using the condenser centering screws on the front right and left of the condenser,
move the small lighted portion of the field to the center of the visual field.
Step 4. Now look to see whether the leaves of the iris field diaphragm are sharply defined
(focused) or not. If they are not sharply defined, then they can be focused distinctly by
changing the height of the condenser up and down with the condenser focusing knob while
you are looking through the binoculars. Once you have accomplished the precise focusing of
the radiant field diaphragm leaves, open the radiant field diaphragm until the leaves just
disappear from view.
VII-43
-------
Step 5. The aperture diaphragm of the condenser is adjusted now to make it compatible with
the total numerical aperture of the optical system. This is done by removing an ocular, looking
into the tube at the rear focal plane of the objective, and stopping down the aperture diaphragm
iris leaves until they are visible just inside the rear plane of the objective.
Step 6. After completing the adjustment of the aperture diaphragm in the condenser, return
the ocular to its tube and proceed with the adjustments required to establish either D.I.C. or
Hoffman modulation® optics.
VII-44
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SECTION VIII. VIRUS MONITORING PROTOCOL FOR THE ICR
TABLE OF CONTENTS
FOREWORD VIII-3
PART 1 — SAMPLE COLLECTION PROCEDURE VIII-4
APPARATUS AND MATERIALS VIII-4
MEDIA AND REAGENTS VIII-11
PROCEDURE VIII-12
PART 2 — SAMPLE PROCESSING VIII-16
QUALITY CONTROL AND PERFORMANCE EVALUATION SAMPLES . . VIII-16
QC Samples VIII-16
PE Samples VIII-16
ELUTION PROCEDURE VIII-17
Apparatus and Materials VIII-17
Media and Reagents VIII-17
Procedure VIII-18
ORGANIC FLOCCULATION CONCENTRATION PROCEDURE VIII-19
Apparatus and Materials VIII-19
Media and Reagents VIII-20
Procedure VIII-20
PART 3 — TOTAL CULTURABLE VIRUS ASSAY VIII-23
QUANTAL ASSAY VIII-23
Apparatus and Materials VIII-23
Media and Reagents VIII-23
Sample Inoculation and CPE Development VIII-23
Virus Quantitation: VIII-27
REDUCTION OF CYTOTOXICITY IN SAMPLE CONCENTRATES VIII-28
Media and Reagents VIII-28
Procedure for Cytotoxicity Reduction VIII-29
PART 4 — CELL CULTURE PREPARATION AND MAINTENANCE VIII-30
PREPARATION OF CELL CULTURE MEDIUM VIII-30
General Principles VIII-30
Apparatus and Materials VIII-30
Media and Reagents VIII-32
Media Preparation Recipes VIII-32
PREPARATION AND PASSAGE OF BGM CELL CULTURES VIII-35
Vessels and Media for Cell Growth VIII-35
General Procedure for Cell Passage VIII-35
VIII-1
-------
Procedure For Performing Viable Cell Counts VIII-37
PROCEDURE FOR PRESERVATION OF BGM CELL LINE VIII-38
Preparation of Cells for Storage VIII-38
Procedure for Freezing Cells VIII-39
Procedure for Thawing Cells VIII-39
PART 5 — STERILIZATION AND DISINFECTION VIII-40
GENERAL GUIDELINES VIII-40
STERILIZATION TECHNIQUES VIII-40
Solutions VIII-40
Autoclavable Glassware, Plasticware, and Equipment VIII-40
Chlorine Sterilization VIII-41
PROCEDURE FOR VERIFYING STERILITY OF LIQUIDS VIII-41
Media and Reagents VIII-42
Verifying Sterility of Small Volumes of Liquids VIII-42
Visual Evaluation of Media for Microbial Contaminants VIII-42
CONTAMINATED MATERIALS VIII-42
PART 6 — BIBLIOGRAPHY AND SUGGESTED READING VIII-43
PART 7 — VENDORS VIII-46
PART 8 — EXAMPLES VIII-48
EXAMPLE 1 VIII-48
EXAMPLE 2 VIII-56
PART 9 — DATA SHEETS VIII-63
VIII-2
-------
FOREWORD
The surface water treatment rule (40 CFR Part 141) established the maximum contam-
ination level for enteric virus in public water systems by requiring that systems using surface
water or ground water under the influence of surface water reduce the amount of virus in
source water by 99.99%. The rule requirements are currently met on basis of treatment alone
(e.g., disinfection and/or filtration), and thus the degree of actual protection against waterborne
viral disease depends upon the source water quality. Utilities using virus-free source water or
source water with low virus levels may be overtreating their water, while utilities using highly
contaminated water may not be providing adequate protection. To determine more adequately
the level of protection from virus infection and to reduce the levels of disinfection and
disinfection byproducts, where appropriate, the U.S. EPA is requiring all utilities serving a
population of over 100,000 to monitor their source water for viruses monthly for a period of 18
months. Systems finding greater than one infectious enteric virus particle per liter of source
water must also monitor their finished water on a monthly basis. The authority for this
requirement is Section 1445(a)(l) of the Safe Drinking Water Act, as amended in 1986.
This Virus Monitoring Protocol was developed by virologists at the U.S. EPA and
modified to reflect consensus agreements from the scientific community and comments to the
draft rule. The procedures contained herein do not preclude the use of additional tests for
research purposes (e.g., polymerase chain reaction-based detection methods for non-cytopathic
viruses).
The concentrated water samples to be monitored may contain pathogenic human enteric
viruses. Laboratories performing virus analyses are responsible for establishing an adequate
safety plan and must rigorously follow the guidelines on sterilization and aseptic techniques
given in Part 5.
Analytical Reagent or ACS grade chemicals (unless specified otherwise) and deionized or
distilled reagent grade water (dH2O; see Table IV-1) should be used to prepare all media and
reagents. The dH2O must have a resistance of greater than 0.5 megohms-cm at 25 °C, but
water with a resistance of 18 megohms-cm is preferred. Water and other reagent solutions
may be available commercially. For any given section of this protocol only apparatus,
materials, media and reagents that are not described in previous sections are listed, except
where deemed necessary. The amount of media prepared for each Part of the Protocol may be
increased proportionally to the number of samples to be analyzed.
VIII-3
-------
PART 1 — SAMPLE COLLECTION PROCEDURE
APPARATUS AND MATERIALS
Several configurations are given below for the assembly of the filter apparatus. The
standard filter apparatus will be used for all sampling, except where aprefilter, dechlorination
orpH adjustment are required.
1. Standard filter apparatus (see Figure Vni-1).
a. Parts needed (letters in bold print represent the origin of the abbreviations used to
identify parts in the figures):
i. One BR — Backflow Regulator (Watts Regulator1 Product Series 8 — 3/4" Hose
Connection Vacuum Breaker).
ii. One SF — Swivel Female insert with garden hose threads (United States Plastic
Product No. 63003).
iii. Three sections of BT — Braided Tubing, 1A" clear (Cole-Parmer Product No. G-
06401-03).
iv. Six HC1 — Hose Clamps (Cole-Parmer Product No. G-06403-20).
v. One HF1 — Hose Fitting, nylon, %" male NPT x i/2" tubing ID (United States
Plastic Product No. 61141).
vi. One PR — Pressure Regulator (Watts Regulator Product No. %" 26A (or
263A), Suffix B).
vii. One PN — PVC Nipple, %" male NPT (Ryan Herco Product No. 3861-057; not
required with the 263 A regulator).
viii. One TE — PVC TEE with %" female NPT ports (Ryan Herco Product No.
3805-003; not required with the 263 A regulator).
ix. One RB1 — Reducing Bushing, %" NPT(M) x i/4» NPT(F) (Cole-Parmer
Product No. G-06349-32; not required with the 263 A regulator).
JSee Part 7 for addresses of the vendors listed. The vendors listed in this protocol
represent one possible source for required products. Other vendors may supply the same
or equivalent products.
VIII-4
-------
WATER SOURCE
Insertion Point for Additional Modules
(If required)
RN1 FQ1 HC1
Figure VIII-L
Standard Filter Apparatus
-------
x. One PG — Pressure Gauge 0-30 pound per square inch (PSI; Cole-Partner
Product No. G-68004-03; place in Vi" gauge port if using the 263 A regulator).
xi. One RA — Reducing Adaptor, 1/2" female NPT x 3/B» maie ^pj (Cincinnati
Valve and Fitting Product No. SS-8-RA-6).
xii. One MQ1 — Male Quick Connect, 1A" male NPT (Cincinnati Valve and Fitting
Product No. SS-QF8-S-8PM; appropriate hose fittings and braided tubing can
be substituted for quick connects).
xiii. Two FQ1 — Female Quick Connects, V^" female NPT (Cincinnati Valve and
Fitting Product No. SS-QF8-B-8PF).
xiv. Two RN1 — Reducing Nipples, 3/4" male NPT x i/2» male NPT (Cole-Partner
Product No. G-06349-3 5).
xv. One CH — Cartridge Housing with wench (Cuno Product No. AP 1 1 T).
xvi. One FC — Filter Cartridge, positively charged 1MDS, ZetaPor Virosorb (Cuno
Product No. 45144-01-1MDS).
xvii. One MQ2 — Male Quick Connect, 1A" female NPT (Cincinnati Valve and
Fitting Product No. SS-QF8-S-8PF).
xviii. One HF2 — Hose Fitting, 1/2" male NPT x ^"tubing ID (United States Plastic
Product No. 62142).
xix. One WM — Water Meter (Neptune Equipment Product No. 5/a" Trident 10).
The water meter should be used in a horizontal position and protected from
freezing. The order should specify that the meters be rated in gallons (1 gal =
0.1337 ft3 or 3.7854 L). If not specified, meters may be rated in cubic feet (1 ft3
= 7.481 gal or 28.3 16 L).
xx. One HF3 — Hose Fitting, nylon, 3/4" male NPT x i/2" tubing ID (United States
Plastic Product No. 61 143).
xxi. One FV — Flow Control Valve (Plast-O-Matic Valves Product No. FC075B-3-
PVC).
VIII-6
-------
b. Apparatus assembly — the standard filter apparatus consists of three modules: the
regulator module, the cartridge housing module and the discharge module.
Teflon tape (Cole-Parmer Product No. G-08782-27) must be used on all threaded,
non-compression fittings. It is recommended that apparatus assembly be performed by
the analytical laboratory contracted by the utility to analyze ICR samples for viruses).
i. Regulator module — in order, as shown in Figure VIII-1, connect the backflow
regulator (BR) to a swivel female insert (SF). Clamp a piece of braided tubing
(BT) onto the tubing connector of the swivel female insert using a hose clamp
(HC1). Clamp the other end of the tubing to a % x y2" hose fitting (HF1).
Screw the fitting into the inlet of the pressure regulator (PR). Connect the outlet
of the pressure regulator to the PVC TEE (TE) via a PVC nipple (PN). Connect
the pressure gauge (PG) to the top of the PVC TEE using the reducing bushing
(RB). Attach a reducing adaptor (RA) to the remaining connection on the PVC
TEE. Add a male quick connect (MQ1) to the reducing adaptor.
ii. Cartridge housing module — Attach a female quick connect (FQ1) to a reducing
nipple (RN1). Connect the reducing nipple to the inlet of the cartridge housing
(CH). Attach another reducing nipple to the outlet of the housing. Attach a
male quick connect (MQ2) to the reducing adaptor.
iii. Discharge module — attach a female quick connect (FQ 1) to a hose fitting
(HF2). Connect a piece of braided tubing to the hose fitting with a hose clamp
(HC1). Clamp the other end of the braided tubing to a swivel female insert with
another hose clamp. Attach a swivel female insert to the inlet of the water meter
(WM). Attach another swivel female insert to the outlet of the meter and
connect a piece of braided tubing with a hose clamp. Clamp the other end of the
tubing to a hose fitting (FTF3) with a hose clamp. Screw the fitting into the inlet
of the flow control valve (FV). An additional hose fitting (not shown) may be
added to the flow control valve for the attachment of a sufficient length of
tubing to reach a drain. The discharge module does not have to be sterilized.
iv. Connect the cartridge housing module to the regulator module at the quick
connect. The combined regulator and cartridge housing modules should be
sterilized with chlorine as described in Part 5. Presterilize a 1MDS filter
cartridge (FC) as described in Part 5 and place it into the cartridge housing
using aseptic technique. Replace the housing head of the cartridge housing and
tighten with a cartridge housing wench. Check to ensure that the filter is
adequately sealed by shaking the housing. Adequately sealed filters should not
move. For convenience during shipping, the regulator and cartridge housing
modules may be separated. Seal all openings into the modules with sterile
aluminum foil.
VIII-7
-------
2. Prefilter module for waters exceeding 75 nephelometric turbidity units (NTU) and for any
other conditions that prevent the minimum sampling volumes from being obtained (see Figure
VIII-2)
a. Additional parts needed: One PC — 10 jim Polypropylene Prefilter Cartridge
(Parker Hannifin Product No. M19R10-A); in addition, a female quick connect (FQ1),
two reducing nipples (RN1), a cartridge housing (CH) and a male quick connect (MQ2)
as described for the standard apparatus are needed.
b. Module assembly — in order, as shown for the prefilter module in Figure VIII-2,
attach a female quick connect (FQ1) to a reducing nipple (RN1). Connect the reducing
nipple to the inlet of the cartridge housing (CH). Attach another reducing nipple to the
outlet of the housing. Attach a male quick connect (MQ2) to the reducing adaptor.
Sterilize the unit with chlorine as described in Part 5 and add a presterilized polypropy-
lene prefilter cartridge using aseptic technique. Cover the ends with sterile aluminum
foil. The prefilter module may be sent to the utility and stored in a clean location until
needed.
3. Injector modules for source or finished water requiring pH reduction and for finished
waters requiring dechlorination (see Figure VIII-2).
a. Additional parts needed:
i. Two FQ2 — Female Quick Connects, 1A" male NPT (Cincinnati Valve and
Fitting Product No. SS-QF8-B-8PM).
ii. Four ME — Male Elbows, %" male NPT (Cincinnati Valve and Fitting Product
No. SS-6-ME).
iii. Two RN2 — Reducing Nipples, %" male NPT x y2" male NPT (Cole-Parmer
Product No. G-6349-85).
iv. Two RB2 — Reducing Bushings, %" female NPT x i/2» male NPT (Cole-
Parmer Product No. G-06349-34).
v. Three IN — In-line INjectors (DEMA Engineering Product No. 203B %"
female NPT; a metering pump and appropriate connectors may be substituted
for an injector).
vi. Three HC2 — Hose Clamps (Cole-Parmer Product No. G-06403-10).
VIII-8
-------
Figure VIII-2.
Additional Modules for the
Standard Filter Apparatus
Single Injector Module
FQ2
Prefilter Module
FQ1
MQ2
PC
PN TE MQ1
RA HC2
IT
to additive
reservoir
Double Injector Module
RB2
MQ2 (iof2)
ME (iof4)
|Q FQ1 (lot 2)
HC2 (1 of 2)
IT (1 of 2)
to additive
reservoirs
-------
vii. In addition, four reducing adaptors (RA), four PVC TEEs (TE), two PVC
nipples (PN), two reducing bushings (RBI), two pressure gauges (PG), two
female quick connects (FQ1), two male quick connects (MQ1) and two male
quick connects (MQ2) as described for the standard apparatus are needed. Two
union ball joints, %" female NPT (not shown; Cincinnati Valve and Fitting
Product No. SS-6-UBJ) and two PVC nipples may be used in place of the two
reducing nipples (RN2), male quick connects (MQ2), female quick connects
(FQ1) and reducing bushings (RB2) used with the double injector module.
b. Module assembly:
i. Single Injector Module — assemble the parts in order as shown for the single
injector module in Figure VIII-2. Attach a female quick connect (FQ2) to a
reducing adaptor (RA). Connect the adaptor to the inlet of the injector (IN).
Connect the outlet of the injector to a PVC TEE (TE) via a PVC nipple (PN).
Connect a pressure gauge (PG) to the top of the PVC TEE using a reducing
bushing (RBI). Attach a reducing adaptor (RA) to the remaining connection on
the PVC TEE. Add a male quick connect (MQ1) to the reducing adaptor.
ii. Double Injector Module — assemble the parts as shown for the double injector
module in Figure VIII-2. Assemble the main portion by attaching a female
quick connect (FQ2) to a reducing adaptor (RA). Connect the adaptor to the top
connector of a PVC TEE (TE). Add a male elbow (ME) to one of the connec-
tions on the PVC TEE. Attach a reducing nipple (RN2) to the other connection.
If using a union ball joint in place of the quick connects, attach a PVC nipple
(not shown) to the other connection. Add a male quick connect (MQ2) to the
reducing nipple or add one portion of a union ball joint (not shown) to the PVC
nipple. Connect the inlet side of an injector (IN) to the male elbow. Attach
another male elbow to the outlet of the injector. Connect the male elbow to
another PVC TEE. Connect a reducing nipple (RN2 or PVC nipple) to the other
end of the second PVC TEE. Add a male quick connect (MQ2) to the reducing
nipple as above (or add one portion of the second union ball joint to the PVC
nipple). Connect the top connector of the second PVC TEE to a third PVC TEE
via a PVC nipple (PN). Connect a pressure gauge (PG) to the top of the third
PVC TEE using a reducing bushing (RB1). Attach a reducing adaptor (RA) to
the remaining connection on the third PVC TEE. Add a male quick connect
(MQ1) to the reducing adaptor. Attach two male elbows (ME) to the inlet and
outlet of a second injector (IN). Connect two reducing bushings (RB2) or, if
used, the bottom portion or the two union ball joints (not shown) to the male
elbows. Connect a female quick connect (FQ1) to each reducing bushing.
Orient the second injector so that the direction of flow is the same as the first
injector (the arrows on the injectors should both point towards the pressure
gauge side of the assembly). Connect the two female quick connects to the male
VIII-10
-------
quick connects of the main portion to complete the assembly or, if used, connect
the two portions of the union ball joints.
iii. Sterilize the single and double modules with chlorine as described in Part 5.
Cover the ends, including the injector port, with sterile aluminum foil. Sterilize
the inside and outside surfaces of the Injector Tubing (IT; injector tubing is sup-
plied with each injector). Place the tubing in a sterile bag or wrapping in such a
way that the ends may be removed without contaminating them. The injector
modules may be shipped to the utility and stored in a clean location until
needed.
4. Portable pH probe (Omega Product No. PHH-1X)
5. Portable temperature probe (Omega Product No. HH110).
6. Commercial ice packs (Cole-Parmer Product No. L-06346-85).
7. One liter polypropylene wide-mouth bottles (Nalge Product No. 2104-0032).
8. Insulated shipping box with carrying strap (17" x 17" x 13"; Cole-Parmer Product No. L-
03748-00 and L-03742-30).
9. Miscellaneous — aluminum foil, data card (see Part 9), hosecock clamp, surgical gloves,
screwdriver or pliers for clamps, waterproof marker.
10. Chemical resistant pump capable of supplying 30 PSI at 3 gal/min and appropriate
connectors (for use where garden hose-type pressurized taps for the source or finished water to
be monitored are unavailable and for QC samples). Follow the manufacturer's recommenda-
tions for pump priming.
MEDIA AND REAGENTS
1. 2% sodium thiosulfate (Na2S2O3) — dissolve 100 g of Na2S2O3 in a total of 5000 mL
dH2O to prepare a stock solution. Autoclave for 30 min at 121 °C.
2. Hydrochloric acid (HC1) — Prepare 0.1, 1 and 5 M solutions by mixing 50, 100 or 50 mL
of concentrated HC1 with 4950, 900 or 50 mL of dH2O, respectively. Prepare solutions to be
used for adjusting the pH of water samples at least 24 h before use.
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PROCEDURE
Operators must wear surgical gloves and avoid conditions that can contaminate a
sample with virus. Gloves should be changed after touching human skin or handling compo-
nents that may be contaminated (e.g., water taps, other environmental surfaces).
Step 1. Purge the water tap to be sampled before connecting the filter apparatus. Continue
the purging for 3-3 min or until any debris that has settled in the tap line has cleared. Then
turn off the water tap.
Source water sampling must be conducted at the plant intake, before impoundment,
chlorination or any other treatment. Finished water sampling must be conducted at the point
of entry into the distribution system. If it is necessary to use a pump for sampling, sterilize the
pump with chlorine as described in Part 5 or flush with 20 gal of water to be sampled before
each use.
Step 2. Remove the foil from the backflow regulator (see Figure Vni-1) on a regulator
module. Loosen the swivel female insert slightly to allow it to turn freely and connect the
backflow regulator to the tap. Retighten the swivel female insert. Disconnect the cartridge
housing module at the quick connect following the pressure gauge (the insertion point shown
in Figure VDI-1), if connected, and cover the open ends leading into the modules with sterile
foil.
Step 3. Remove the foil from the ends of the discharge module and from the free end of the
regulator module. Connect the discharge module to the regulator module. Place the control
flow valve or tubing connected to the outlet of the flow control valve into a one liter plastic
bottle. Note that the injector module, the prefilter module and the cartridge housing module
must not be attached to the apparatus at this stage of the procedure!
Step 4. Slowly turn on the tap and adjust the pressure regulator until the pressure gauge on
the regulator module reads 30 PSI. If the tap is incapable of 30 PSI, adjust the regulator to
achieve the maximum pressure. Pressures less than 30 PSI will result in a reduced flow rate
and thus longer sampling times. Flush the apparatus assembly with at least 20 gal of the water
to be sampled. While the system is being flushed, measure the pH, the temperature and the
turbidity on the water collecting in and overflowing from the one liter plastic bottle. Record
the values onto the Sample Data Sheet (see Part 9).
The pHmeter should be calibrated before each use for the pH range of the water to be
sampled.
The turbidity reading may be taken from an in-line turbidimeter connected to the tap
being used.
Step 5. If the sample has a pH above 8.0 or contains a disinfectant, turn off the water at the
tap and disconnect the discharge module from the regulator module. Remove the foil from the
VIII-12
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ends of a single injector module (see Figure Vni-2) and connect the module to the male quick
connect of the regulator module. Reattach the discharge module.
Step 6. If the sample has a pH above 8.0 and contains a disinfectant, turn off the water at
the tap and disconnect the discharge module from the regulator module. Remove the foil from
the ends of a double injector module (see Figure Vni-2) and connect the module to the male
quick connect of the regulator module. Reattach the discharge module.
Step 7. If an injector module has been added, remove the foil from the injector port(s) and
attach the injector tubing to each port. Add a hosecock clamp to each injector tubing and
tighten completely to prevent flow into the injector(s). Turn the fine metering adjustment
screw on each injector (the smaller screw) clockwise as far as it will go to minimize the flow
rate until the injectors are adjusted (note that the injectors were designed to have a minimum
flow rate of 20-30 mL/min; thus completely closing the fine metering adjustment screw does
not stop the flow). Place the other end of each tubing into the appropriate sterile graduated
container containing 0.1 M HC1 or 2% thiosulfate. Take care not to touch or contaminate the
surfaces of the injector tubing that will be placed in the graduated containers. Slowly turn on
the tap again and readjust the pressure regulator, if necessary.
Step 8. If a single injector module has been added, continue to flush the apparatus and
adjust the water bypass screw on the injector (the larger adjustment screw) until the pressure
gauge on the injector module is about 35% less than the pressure gauge on the regulator
module (e.g., 19 PSI when the gauge on the regulator module reads 30 PSI; a minimum of a
35% pressure drop is required to achieve suction). Loosen the hosecock clamp and observe
whether suction is occurring. If not, slowly increase the pressure drop until suction starts.
a. If the pH value of the water sample is greater than 8.0, ensure that the injector tubing
is placed into a graduated container containing 0.1 M HC1. While continuing to measure
the pH in the one liter plastic bottle, adjust the fine metering adjustment screw on the
injector to add sufficient HC1 to give a pH of 6.5 to 7.5. It may be necessary to use the
hosecock clamp to reduce the flow rate to less than 20-30 mL/min or to use a more dilute
or concentrated HC1 solution with some water samples. When the pH stabilizes at a pH of
6.5 to 7.5, continue with Step 10. Record the adjusted pH onto the Sample Data Sheet.
b. If the water to be sampled contains a disinfectant, ensure that the injector tubing is
placed into a graduated container containing 2% thiosulfate. Adjust the fine metering
adjustment screw on the injector to add thiosulfate at a rate of 10 mL/gal (2.6 mL/L or 30
mL/min at a flow rate of 3 gal/min; note that at this rate, approximately 3-4 L of thio-
sulfate solution will be required per sample). When the proper rate is achieved, record the
addition of thiosulfate on the Sample Data Sheet and continue with Step 10.
Step 9. If a double injector module is being used, continue to flush the apparatus and turn
the water bypass screws on each injector clockwise as far as possible. Then turn the water
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bypass screws on each regulator one half turn counter clockwise. Continue turning the screws
evenly one half turn counter clockwise until the pressure gauge on the double injector module
is 35% less than the pressure gauge on the regulator module. Ensure that the tubing from one
injector is placed into a graduated container containing 0.1 M HC1 and the other into a
graduated container containing 2% sodium thiosulfate. Loosen the hosecock clamps. Since
there may be slight differences between the injectors and since the pressure reading after the
injectors reflects an average pressure drop from both injectors, some additional adjustment of
the water bypass screws may be required to obtain suction on each injector. After confirming
that each injector is drawing fluid, adjust the flow of HC1 and thiosulfate as in Step 8a-8b
above. Record the final pH and the addition of thiosulfate on the Sample Data Sheet and
continue with Step 10.
Step 10. After adjusting the injectors, if required, and flushing the system with at least 20 gal,
turn off the flow of water at the sample tap and remove the discharge module. If the water
sample has a turbidity greater than 75 NTU, remove the foil from each end of the prefilter
module and connect the prefilter module (see Figure Vni-2) to the end of the regulator
module or to the end of one of the injector modules, if used. Remove the foil from the
cartridge housing module and connect it to the end of the regulator module, or to the end of the
injector module or the prefilter module, if used. Connect the discharge module to the cartridge
housing module.
Step 11. Record the sample number, location, date, time of day and initial gallon (or cubic
feet) reading from the water meter onto the Sample Data Sheet.
Use the unique utility-specific sample numbers assigned by the ICR Joint Application
Design database.
Step 12. Slowly turn on the water with the filter housing placed in an upright position, while
pushing the red vent button on top of the filter housing to expel air. When the air is totally
expelled from the housing, release the button, and open the sample tap completely. Readjust
to 30 PSI, if necessary. Check the thiosulfate usage rate or the pH of the discharged water if
an injector(s) is being used and readjust, if necessary.
Step 13. Sample a minimum volume for source water of 200 L (7.1 ft3, 52.8 gal) and for
finished water of 1500 L (53.0 ft3, 396.3 gal). Samples for source and finished waters must not
exceed 300 L (10.6 ft3, 79.3 gal) and 1800 L (63.6 ft3, 475.5 gal), respectively. For source
water the total amount of sample that can be passed through a filter will depend upon water
quality, however, it should be possible to obtain the minimum volume using the procedures
described above.
Samples should be monitored periodically during the sampling. If the filter clogs, contact
the approved analyst for further instructions. Since the flow rate may change during sampling
due to filter clogging, thiosulfate addition and the adjusted pH of the sample must be checked
regularly.
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Step 14. Turn off the flow of water at the sample tap at the end of the sampling period and
record the date, time of day, and final gallon (or cubic feet) reading from the water meter onto
the Sample Data Sheet. Although the final water meter reading may be affected by the addi-
tion of HC1 and/or thiosulfate, the effect is considered insignificant and may be ignored.
Step 15. Loosen the swivel female insert on the regulator module and disconnect the backflow
regulator from the tap. Disconnect the cartridge housing module and the prefilter housing
module, if used from the other modules. Turn the filter housing(s) upside down and allow
excess water to flow out as waste water. Turn the housing(s) upright and cover the quick
connects on each end of the modules with sterile aluminum foil.
Step 16. Pack the cartridge housing module(s) into an insulated shipping box. Add 6-8 small
ice packs (prefrozen at -20°C) around the cartridge housings to keep the sample cool in transit
(the number of ice packs may have to be adjusted based upon experience to ensure that the
samples remain cold, but not frozen). Drain and add the regulator and injector modules used.
Place the Sample Data Sheet (protected with a closable plastic bag) in with the sample and
ship by overnight courier to the contracted, approved laboratory for virus analysis. Notify the
laboratory by phone upon the shipment of sample.
The approved laboratory will elute virus from the 1MDS filter (and prefilter, if appropri-
ate) and analyze the eluates as described in Parts 2-3. After removing the filter, the laboratory
will clean, sterilize the apparatus components with chlorine and dechlorinate with sodium
thiosulfate as described in Part 5. After flushing with sterile dH2O, a new 1MDS cartridge
(and prefilter, if appropriate) will be added, the openings sealed with sterile aluminum foil,
and the apparatus returned to the utility for the next sample. The discharge module can be
stored at the utility between samplings. Openings should be covered with aluminum foil
during storage.
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PART 2 — SAMPLE PROCESSING
QUALITY CONTROL AND PERFORMANCE EVALUATION SAMPLES
Quality control (QC) and performance evaluation (PE) samples will be shipped to
analysts seeking approval (see Sections III-IV). PE samples must be successfully analyzed by
each analyst participating in the ICR virus monitoring program as part of the initial approval
process. After initial approval, each analyst must successfully analyze one QC sample set per
sample batch and one PE sample set every month. A QC sample set is comprised of a negative
and a positive QC sample. A sample batch consists of all the ICR samples that are analyzed
by an analyst during a single week. Each sample batch and its associated QC sample set must
be assigned a unique batch number. QC samples do not have to be processed during weekly
periods when no ICR samples are processed. QC andPE data should be sent directly to the
U.S. EPA as specified in Section III.
QC Samples:
1. Negative QC Sample: Place a sterile 1MDS filter into a standard filter apparatus.
Process and analyze the 1MDS filter using the Elution, Organic Flocculation and Total
Culturable Virus Assay procedures given below.
2. Positive QC Sample: Place 40 L of dH2O into a sterile polypropylene container (Cole-
Parmer Product No. G-06063-32) and add 1 mL of a QC stock of attenuated poliovirus
containing 200 PFU/mL2. Mix and pump the water through a standard filter apparatus
containing a 1MDS filter.
Process and analyze the 1MDS filter using the Elution, Organic Flocculation and Total
Culturable Virus Assay procedures given below.
PE Samples:
Process and analyze PE samples according to the Elution, Organic Flocculation and
Total Culturable Virus Assay procedures of this protocol and according to any additional
procedures supplied with the samples.
2 A QC sample with a titer of 200 PFU/mL will be supplied for the QC tests described
in this Section. The titer of this QC sample may be changed before the start or during the
testing phase of the ICR. Analysts must use these samples as supplied and not attempt to
adjust the titer to 200 PFU/mL. A high titer QC sample will also be shipped to each
analyst so that laboratories can develop their own internal QC programs. The high titered
sample is not to be used for the QC tests described in this Section.
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ELUTION PROCEDURE
The cartridge filters must arrive from the utility in a refrigerated, but not frozen, condi-
tion. The arrival condition should be recorded on the Sample Data Sheet (Part 9). Filters
should be refrigerated upon arrival and eluted within 72 h of the start of the sample collection.
Apparatus and Materials:
1. Positive pressure air or nitrogen source equipped with a pressure gauge.
If the pressure source is a laboratory air line or pump, it must be equipped with an oil
filter.
2. Dispensing pressure vessels — 5 or 20 liter capacity (Millipore Corp. Product No. XX67
OOP 05 and XX67 OOP 20).
3. pH meter with combination-type electrode and an accuracy of at least 0.1 pH unit.
4. Autoclavable inner-braided tubing with screw clamps or quick connects for connecting
tubing to equipment.
5. Magnetic stirrer and stir bars.
Media and Reagents:
1. Sodium hydroxide (NaOH) — prepare 1 M and 5 M solutions by dissolving 4 g or 20 g of
NaOH in a final volume of 100 mL of dH2O, respectively.
NaOH solutions may be stored for several months at room temperature.
2. Beef extract V powder (BBL Microbiology Systems Product No. 97531) — prepare
buffered 1.5% beef extract by dissolving 30 g of beef extract powder and 7.5 g of glycine
(final glycine concentration = 0.05 M) in 1.9 L of dH2O. Adjust the pH to 9.5 with 1 or 5 M
NaOH and bring the final volume to 2 L with dH2O. Autoclave at 121 °C for 15 min and use
at room temperature.
Beef extract solutions may be stored for one week at 4 °C or for longer periods at -20 °C.
Screen each new lot of beef extract before use in the Organic Flocculation Concentration
Procedure to determine whether virus recoveries are adequate. Perform the screening by
spiking one liter of beef extract solution with 1 mL of a diluted QC sample containing 200
PFU/mL. Assay the spiked sample according to the Organic Flocculation and Total
Culturable Virus Assay procedures given below. Use a single passage with undiluted sample
and sample diluted 1:5 and 1:25 along with an equivalent positive control. The mean
recovery ofpoliovirusfor three trials should be at least 50%.
VIII-17
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Procedure:
Place a disinfectant-soaked sponge over vents while releasing trapped air or pressure
throughout this procedure to minimize dangers from aerosols.
Step 1. Attach sections of braided tubing (sterilized on inside and outside surfaces with
chlorine and dechlorinated with thiosulfate as described in Part 5) to the inlet and outlet ports
of a cartridge housing module containing a 1MDS filter to be tested for viruses. If a prefilter
was used, keep the prefilter and cartridge housing modules connected and attach the tubing to
the inlet of the prefilter module and to the outlet of the cartridge housing module.
Step 2. Place the sterile end of the tubing connected to the outlet of the cartridge housing
module into a sterile two liter glass or polypropylene beaker.
Step 3. Connect the free end of the tubing from the inlet port of the prefilter or cartridge
housing modules to the outlet port of a sterile pressure vessel and connect the inlet port of the
pressure vessel to a positive air pressure source. Add pressure to blow out any residual water
from the cartridge housing(s). Open the vent/relief valve to release the pressure.
Step 4. Remove the top of the pressure vessel and pour 1000 mL of buffered 1.5% beef
extract (pH 9.5, prewarmed to room temperature) into the vessel. Replace the top of the
pressure vessel and close its vent/relief valve.
Acceptable alternatives to the use of a pressure vessel include 1) the use of a peristaltic
pump and sterile tubing to push the beef extract through the filter and 2) the addition of beef
extract directly to the cartridge housing and the use of positive pressure to push the beef
extract through the filter.
Step 5. Open the vent/relief valve(s) on the cartridge housing(s) and slowly apply sufficient
pressure to purge trapped air from them. Close the vent/relief valve(s) as soon as the buffered
beef extract solution begins to flow from it. Turn off the pressure and allow the solution to
contact the 1MDS filter for 1 min.
Wipe up spilled liquid with disinfectant-soaked sponge. Carefully observe alternative
housings without vents to ensure that all trapped air has been purged.
Step 6. Increase the pressure to force the buffered beef extract solution through the filter(s).
The solution should pass through the 1MDS filter slowly to maximize the elution contact
period. When air enters the line from the pressure vessel, elevate and invert the filter housing
to permit complete evacuation of the solution from the filters.
Step 7. Turn off the pressure at the source and open the vent/relief valve on the pressure
vessel. Place the buffered beef extract from the two liter beaker back into the pressure vessel.
Replace the top of the pressure vessel and close its vent/relief valve. Repeat Steps 5-6.
VIII-18
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Step 8. Turn off the pressure at the source and open the vent/relief valve on the pressure
vessel. Thoroughly mix the eluate. Adjust the pH of the eluate to 7.0-7.5 with 1 M HC1. If
archiving is not required and if the optional coliphage assay is not performed, measure the
volume of the eluate and record it onto the Virus Data Sheet as the Eluate Volume Recov-
ered. Transfer the Total Sample Volume from the Sample Data Sheet to the Adjusted
Total Sample Volume on the Virus Data Sheet.
Step 9. If archiving is required or if the optional coliphage assay (see Section IX. Coliphage
Assay) will be performed, adjust the pH of the eluate to 7.0-7.5 with 1 M HC1. Measure the
volume of the adjusted eluate and record it onto the Virus Data Sheet as the Eluate Volume
Recovered. Determine the amount of sample to be used in the coliphage assay by multiplying
the Eluate Volume Recovered by 0.035. Place a volume equal to the product obtained into a
separate container and store at 4°C. If archiving is not required, multiply the Total Sample
Volume from the Sample Data Sheet by 0.965 and record the product as the Adjusted Total
Sample Volume on the Virus Data Sheet
Step 10. If archiving is required, determine the amount of sample to remove for archiving by
multiplying the Eluate Volume Recovered by 0.1. Record the product onto the Virus Data
Sheet as the Volume of Eluate Archived and place this volume into a separate container.
Freeze3 the archive sample and ship it to the ICR Laboratory Coordinator, USEPA, TSD, 26
W. Martin Luther King Drive, Cincinnati, OH 45268. Multiply the Total Sample Volume
from the Sample Data Sheet by 0.865 if the optional coliphage assay is performed or by 0.9 if
the sample was not assayed for coliphage. Record the product as the Adjusted Total Sample
Volume on the Virus Data Sheet.
Step 11 Proceed to the Organic Flocculation Concentration Procedure immediately If
the Organic Flocculation Concentration Procedure cannot be undertaken immediately,
store the eluate (adjusted to pH 7.0 to 7.5 as described in Step 8b) at 4°C for up to 24 h or for
longer periods at -70°C.
ORGANIC FLOCCULATION CONCENTRATION PROCEDURE
Apparatus and Materials:
1. Refrigerated centrifuge capable of attaining 2,500 -10,000 xg and screw-capped centri-
fuge bottles with 100 to 1000 mL capacity.
3A11 freezing of samples and cell cultures throughout this protocol should be
performed rapidly by placing vessels in a freezer at -70°C or below or in a dry ice-alcohol
bath. Frozen samples and cell cultures should also be thawed rapidly. This may be done
by placing vessels in a 37°C waterbath, but vessel caps must not be immersed and vessels
should be removed from the waterbath as soon as or just before the last ice crystals melt.
VIII-19
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Each bottle must be rated for the relative centrifugal force used.
2. Sterilizing filter — 0.22 jim Acrodisc filter with prefilter (Gelman Sciences Product No.
4525).
Use sterilizing filter stacks on samples that clog commercial filters. Prepare sterilizing
filter stacks using 0.22 jumpore size membrane filters (Millipore Corp. Product No.
GSWP 47 00) stacked with fiberglass prefilters (Millipore Corp. APIS 47 00 andAP20 47 00).
Stack the prefilters and 0.22 pm membrane into a disc filter holder (Millipore Corp. Pro-
duct No. SXOO 47 00) with the AP20 prefilter on top and 0.22 jum membrane filter on bottom.
Disassemble the filter stack after each use to check the integrity of the 0.22 ^m filter. Refilter
any media filtered with a damaged stack.
Always pass about 10 - 20 mL of sterile beef extract, pH 7.0-7.5 (prepared as above,
without pH adjustment), through the filter just before use. This step will reduce virus adsorp-
tion onto the filter membranes.
Media and Reagents:
1. Sodium phosphate, dibasic (Na2HPO4 • 7H2O) — 0.15 M, pH 9.0 - 9.5 or 7.0 - 7.5.
Dissolve 40.2 g of sodium phosphate in a final volume of 1000 mL dH2O. The pH of the
solution should be between 9.0-9.5. Adjust the pH to 9.0 to 9.5 with NaOH, if necessary, or to
7.0 to 7.5 with HCl. Autoclave at 121 °Cfor 15 min.
Procedure:
Minimize foaming (which may inactivate viruses) throughout the procedure by not stirring
or mixing faster than necessary to develop a vortex.
Step 1. Place a sterile stir bar into the beaker containing the buffered beef extract eluate from
the cartridge filter(s). Place the beaker onto a magnetic stirrer, and stir at a speed sufficient to
develop a vortex.
Step 2. Insert a combination-type pH electrode into the beef extract eluate. Add 1 M HCl to
the eluate slowly while moving the tip of the pipette in a circular motion away from the vortex
to facilitate mixing. Continue adding 1 M HCl until the pH reaches 3.5 ± 0.1 and then stir
slowly for 30 min at room temperature.
The pH meter must be standardized atpH 4 and 7. Electrodes must be sterilized before
and after each use as described in Part 5.
A precipitate will form. If pH falls below 3.4, add 1 MNaOH to bring it back to 3.5 ±0.1.
Exposure to apH below 3.4 may result in some virus inactivation.
Step 3. Remove the electrode from the beaker, and pour the contents of the beaker into a
centrifuge bottle. Cap the bottle and centrifuge the precipitated beef extract suspension at
2,500 xg for 15 min at 4°C. Remove and discard the supernatant.
VIII-20
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To prevent the transfer of the stir bar into a centrifuge bottle, hold another stir bar or
magnet against the bottom of the beaker while decanting the contents. The beef extract
suspension will usually have to be divided into several centrifuge bottles.
Step 4. Place a stir bar into the centrifuge bottle that contains the precipitate. Add 30 mL of
0.15 M sodium phosphate, pH 9.0 - 9.5. Place the bottle onto a magnetic stirrer, and stir
slowly until the precipitate has dissolved completely.
Since the precipitate may be difficult to dissolve, it can be partially dispersed with a
spatula before or during the stirring procedure. It may also be dissolved by repeated pipetting
or by shaking at 160 rpmfor 20 min on an orbital shaker in place of stirring. When the
centrifugation is performed in more than one bottle, dissolve the precipitates in a total of 30
mL and combine into one bottle. If the precipitate is not completely dissolved before proceed-
ing, significant virus loss may occur in Step 5. Because virus loss may also occur by pro-
longed exposure to pH 9.0-9.5, laboratories that find it difficult to resuspend the precipitate
may dissolve it initially in 0.15 M sodium phosphate, pH 7.0 - 7.5. If this variation is used, the
pH should be re-adjusted to 9.0-9.5 with 1 MNaOH after the precipitate is completely
dissolved and mixed for 10 min at room temperature before proceeding to Step 5.
Step 5. Check the pH and readjust to 9.0-9.5 with 1 M NaOH, as necessary. Remove the stir
bar and centrifuge the dissolved precipitate at 4,000 -10,000 xg for 10 min at 4°C. Remove
the supernatant and discard the pellet. Adjust the pH of the supernatant to 7.0-7.5 with 1 M
HC1. To remove microbial contamination, load the supernatant into a 50 mL syringe and force
it through a sterilizing filter pretreated with beef extract (laboratories may use other ap-
proaches to remove contamination, but their effectiveness must be documented). Record the
final supernatant (designated the Final Concentrated Sample Volume; FCSV) on the Virus
Data Sheet (see Part 9)
If the sterilizing filter begins to clog badly, empty the loaded syringe into the bottle
containing the unfiltered supernatant, fill the syringe with air, and inject air into filter to force
any residual sample from it. Continue the filtration procedure with another filter.
Step 6. Determine the volume of sample that must be assayed. This volume is at least 100 L
for source water or 1000 L for finished water and is designated the Volume of Original
Water Sample Assayed4 (D). Record the value of D on the Virus Data Sheet. Calculate the
Assay Sample Volume (S) for source and finished water samples using the formula:
S = —— x FCSV
ATSV
Analytical laboratories assaying more than the required volume must use the actual
volume to be assayed in the calculation. See Part 8 for examples of the calculations used
in this protocol.
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where ATSV is the Adjusted Total Sample Volume from the Virus Data Sheet The Assay
Sample Volume is the volume of the Final Concentrated Sample that represents 100 L of
source water or 1000 L of finished water. Record the Assay Sample Volume onto the Virus
Data Sheet. Prepare a subsample (subsample 1) containing a volume 0.55 times the Assay
Sample Volume. Prepare a second subsample (subsample 2) containing a volume that is 0.67
times the Assay Sample Volume Divide the Final Concentrated Sample from QC and PE
samples into two equal subsamples. Calculate the Assay Sample Volume for these samples
by multiplying FCSV by 0.4. Label each subsample with appropriate sampling information
for identification. Hold any portion of the sample that can be assayed within 24 h at 4°C and
freeze all other portions at -70°C.
Final Concentrated Samples, subsamples, PE and QC samples processed to this point by
a laboratory not doing the virus assay must be frozen at -70 °C immediately and then shipped
on dry ice to the laboratory approved for the virus assay.
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PART 3 — TOTAL CULTURABLE VIRUS ASSAY
OUANTAL ASSAY
Apparatus and Materials:
1. Incubator capable of maintaining the temperature of cell cultures at 36.5 ± 1°C.
2. Sterilizing filter — 0.22 |im (Costar Product No. 140666).
Always pass about 10 - 20 mL of 1.5% beef extract, pH 7.0-7.5, through the filter just
before use to minimize virus adsorption to the filter.
Media and Reagents:
1. Prepare BGM cell culture test vessels using standard procedures.
BGMcells are a continuous cell line derived from African Green monkey kidney cells and
are highly susceptible to many enteric viruses (Dahling et al, 1984; Dahling and Wright,
1986). The characteristics of this line were described by Barron et al. (1970). The use of
BGM cells for recovering viruses from environmental samples was described by Dahling et al.
(1974). For laboratories with no experience with virus recovery from environmental samples,
the media and procedures described by Dahling and Wright (1986) and given in Part 4 are
recommended for maximum sensitivity.
EPA will supply an initial culture of BGM cells at about passage 117 to all laboratories
seeking approval. Upon receipt, laboratories must prepare an adequate supply of frozen
BGM cells using standard procedures to replace working cultures that become contaminated
or lose virus sensitivity. A Procedure for Preservation of the BGM Cell Line is given in Part
4. Only BGM cells from the U.S. EPA and between passage 117 and 250 may be usedfor
virus monitoring under the ICR.
Sample Inoculation and CPE Development:
Cell cultures usedfor virus assay are generally found to be at their most sensitive level
between the third and sixth days after their most recent passage. Those older than seven days
should not be used.
Step 1. Identify cell culture test vessels by coding them with an indelible marker. Return the
cell culture test vessels to a 36.5 ± 1 °C incubator and hold at that temperature until the cell
monolayer is to be inoculated.
Step 2. Decant and discard the medium from cell culture test vessels. Wash the test vessels
with a balanced salt solution or maintenance medium without serum using a wash volume of at
least 0.06 mL/cm2 of surface area. Rock the wash medium over the surface of each monolayer
several times and then decant and discard the wash medium.
Do not disturb the cell monolayer.
VIII-23
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Step 3. Determine the Inoculum Volume by dividing the Assay Sample Volume by 20.
Record the Inoculum Volume onto the Virus Data Sheet. The Inoculum Volume should be
no greater than 0.04 mL/cm2 of surface area. If the Inoculum Volume is greater than 0.04
mL/cm2, use larger culture vessels.
Step 4. Inoculate each BGM cell culture test vessel with an amount of assay control or water
sample equal to the Inoculum Volume and record the date of inoculation on the Sample Data
Sheet (see Part 9)
Avoid touching either the cannula or the pipetting device to the inside rim of the cell
culture test vessels to avert the possibility of transporting contaminants to the remaining
culture vessels.
For ease of inoculation, a sufficient quantity of0.15MNa2HPO4, pH 7.0 - 7.5, may be
added to the Inoculum Volume to give a more usable working Inoculation Volume (e.g., 1.0
mL). For example, if an Inoculum Volume ofO. 73 mL is to be placed onto 10 vessels, then
10.5 x (1 - 0.73 mL) = 2.84 mL of sodium phosphate, pH 7.0-7.5 could be added to 10.5 x
0.73 = 7.67 mL ofsubsample. Each milliliter of the resulting mixture will contain the required
Inoculum Volume.
a. Total Culturable Virus Assay Controls:
Run a negative and positive assay control with every group ofsubsamples
inoculated onto cell cultures.
i. Negative Assay Control: Inoculate a BGM culture with a volume of sodium
phosphate, pH 7.0 - 7.5, equal to the Inoculation Volume. This culture will
serve as negative control for the tissue culture quantal assay. If any Negative
Assay Control develops cytopathic effects (CPE), all subsequent assays of
water samples should be halted until the cause of the positive result is deter-
mined.
ii. Positive Assay Control: Dilute attenuated poliovirus type 3 (from the high
titered QC stock) in sodium phosphate, pH 7.0 - 7.5, to give a concentration of
20 PFU per Inoculation Volume. Inoculate a BGM culture with an amount of
diluted virus equal to the Inoculation Volume. This control will provide a
measure for continued sensitivity of the cell cultures to virus infection. Addi-
tional positive control samples may be prepared by adding virus to a small
portion of the final concentrated sample and/or by using additional virus types.
If any Positive Assay Control fails to develop CPE, all subsequent assays of
water samples should be halted until the cause of the negative result is deter-
mined. It may be necessary to thaw and use an earlier passage of the BGM cell
line supplied by the U.S. EPA.
VIII-24
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b. Inoculation of Water Samples
i. Rapidly thaw subsample 1, if frozen, and inoculate an amount equal to the
Inoculum Volume onto each of 10 cell cultures. If there is no evidence for
cytotoxicity and if at least three cell cultures are negative for CPE after seven
days (see below), thaw subsample 2 and inoculate an amount equal to the
Inoculum Volume onto each of 10 additional cultures.
Hold a thawed subsample for no more than 4 hat 4 °C. Warm the subsam-
ple to room temperature just before inoculation.
A small portion of the Final Concentrated Sample may by inoculated onto
cultures several days before inoculating subsample 1 as a control for cytotoxic-
ity.
ii. If cytotoxicity is not a problem and more than seven cultures are positive for
CPE after seven days, prepare five- and twenty five-fold dilutions of subsample
2. To prepare a 1:5 dilution, add a volume equal to 0.1334 times the Assay
Sample Volume (amount "a") to a volume of 0.15 M sodium phosphate (pH
7.0-7.5) equal to 0.5334 times the Assay Sample Volume (amount "b"). After
mixing thoroughly, prepare a 1:25 dilution by adding amount "a" of the 1:5
diluted sample to amount "b" of 0.15 M sodium phosphate (pH 7.0-7.5). Using
an amount equal to the Inoculum Volume, inoculate 10 cell cultures each with
undiluted subsample 2, subsample 2 diluted 1:5 and subsample 2 diluted 1:25,
respectively. Freeze the remaining portions of the 1:25 dilution at -70°C until
the sample results are known. If the inoculated cultures are all positive, thaw the
remaining 1:25 dilution and prepare 1:125, 1:625 and 1:3125 dilutions by
transferring amount "a" of each lower dilution to amount "b" of sodium phos-
phate as described above. Inoculate 10 cultures each with the additional dilu-
tions and freeze the remaining portion of the 1:3125 dilution. Continue the
process of assaying higher dilutions until at least one test vessel at the highest
dilution tested is negative. Higher dilutions can also be assayed along with the
initial undiluted to 1:25 dilutions if it is suspected that the water to be tested
contains more than 500 most probable number (MPN) of infectious total
culturable virus units per 100 L.
iii. If subsample 1 is cytotoxic, then five cell cultures should be inoculated with
Final Concentrated Sample using the same volume required for subsample 1 and
the procedures described in the Reduction of Cytotoxicity in Sample Concen-
trates section below. If these procedures remove cytotoxicity, inoculate
subsample 2 using the procedures for removal of cytotoxicity and 10 cultures
each with undiluted sample, sample diluted 1:5 and sample diluted 1:25 as in
Step 4bii above. If the procedures fail to remove cytotoxicity, write for advice
on how to proceed to the ICR Laboratory Coordinator, U.S. EPA, Office of
Ground Water and Drinking Water, Technical Support Division, 26 W. Martin
Luther King Drive, Cincinnati, OH 45268.
VIII-25
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A maximum of 60 and 580 MPN units per 100 L can be demonstrated by
inoculating a total of 20 cultures with the undiluted Assay Sample Volume from
source water or a total of 10 cultures each with undiluted sample and sample
diluted 1:5 and 1:25, respectively.
c. Inoculation of QC and PE Samples: prepare five-fold dilutions of subsample 1 for
each negative QC sample as described in Step 4bii. Prepare five- and twenty five-fold
dilutions for each positive QC and PE sample. Inoculate 10 cultures with undiluted
subsample and each diluted subsample using an amount of inoculum equal to the
Inoculum Volume.
Use subsample 2 only as a backup for problems with the analysis of subsample 1.
Step 5. Rock the inoculated cell culture test vessels gently to achieve uniform distribution of
inoculum over the surface of the cell monolayers. Place the cell culture test vessels on a level
stationary surface at room temperature so that the inoculum remains distributed evenly over
the cell monolayer.
Step 6. Continue incubating the inoculated cell cultures for 80 - 120 min to permit viruses to
adsorb onto and infect cells.
It may be necessary to rock the vessels every 15-20 min or to keep them on a mechanical
rocking platform during the adsorption period to prevent cell death in the middle of the vessels
from dehydration.
Step 7. Add liquid maintenance medium (see Item 2 of Vessels and Media for Cell Growth
in Part 4 for recommended medium) and incubate at 36.5 ± 1 °C.
Warm the maintenance medium to 36.5 ± 1 °C before placing it onto cell monolayers.
Add the medium to the side of the cell culture vessel opposite the cell monolayer. Avoid
touching any pipetting devices used to the inside rim of the culture vessels to avert the
possibility of transporting contaminants to the remaining vessels. The cultures may be re-fed
with fresh maintenance medium after 4-7 days.
Step 8. Examine each culture microscopically for the appearance of CPE daily for the first
three days and then every couple of days for a total of 14 days.
CPE may be identified as cell disintegration or as changes in cell morphology. Round-
ing-up of infected cells is a typical effect seen with enterovirus infections. However, uninfected
cells round-up during mitosis and a sample should not be considered positive unless there are
significant clusters ofrounded-up cells over and beyond what is observed in the uninfected
controls. Photomicrographs demonstrating CPE appear in the reference byMalherbe and
Strickland-Cholmley (1980).
Step 9. Freeze cultures at -70 °C when more than 75% of the monolayer shows signs of CPE.
Freeze all remaining negative cultures, including controls, after 14 days.
VIII-26
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Step 10. Thaw all the cultures to confirm the results of the previous passage. Filter at least
10% of the medium from each vessel that was positive for CPE or that appeared to be
bacterially contaminated through separate 0.22 jim sterilizing filters. Then inoculate another
BGM culture with 10% of the medium from the previous passage for each vessel, including
those that were negative. Repeat Steps 7-8.
Confirmation passages may be performed in small vessels or multiwell trays, however, it
may be necessary to distribute the inoculum into several vessels or wells to insure that the
Inoculum Volume is less than or equal to 0.04 mL/cm2 of surface area.
Step 11. Score cultures that developed CPE in both the first and second passages as confirmed
positives. Cultures that show CPE in only the second passage must be passaged a third time
along with the negative controls according to Steps 9-10. Score cultures that develop CPE in
both the second and third passages as confirmed positives.
Cultures with confirmed CPE may be stored in a-70 °C freezer for research purposes or
for optional identification tests.5
Virus Quantitation:
Step 1. Record the total number of confirmed positive and negative cultures for each
subsample onto the Total Culturable Virus Data Sheet (Part 9). Do not include the results
of tests for cytotoxicity!
Step 2. Transfer the number of cultures inoculated and the confirmed number of positive
cultures from the Total Culturable Virus Data Sheet for each subsample to the Quantitation
of Total Culturable Virus Data Sheet. If dilutions are not required, add the values to obtain
a total undiluted count for each sample. Calculate the MPN/mL value (Mm) and the upper
(CLum) and lower (CLlm) 95% confidence limits using the total undiluted count. If dilutions are
required, calculate the MPN/mL value and 95% confidence limits using only the subsample 2
values Place the values obtained onto the Quantitation of Total Culturable Virus Data
Sheet. The MPNV computer program supplied by the U.S. EPA must be used for the
calculation of all MPN values and confidence limits.
Step 3. Calculate the MPN per 100 liter value (Mj) of the original water sample according
the formula:
100 M S
M, = —
1 D
5For more information see Chapter 12 (May 1988 revision) of Berg et al. (1984).
VIII-27
-------
where S equals the Assay Sample Volume and D equals the Volume of Original Water
Sample Assayed (the values for S and D can be found on the Virus Data Sheet). Record the
value of M! onto the Virus Data Sheet.6
Step 4. Calculate the lower 95% confidence limit per 100 liter value (CL^ for each water
sample according to the formula:
100 CL, S
CL, = *2-
1 D
where CLlm is the lower 95% confidence limit per milliliter from the Quantitation of Total
Culturable Virus Data Sheet. Calculate the upper 95% Confidence Limit per 100 liter value
(CLU) according to the formula:
100 CL S
CL =
D
where CLum is the upper 95% confidence limit per milliliter from the Quantitation of Total
Culturable Virus Data Sheet. Record the limit per 100 liter values on the Virus Data Sheet.
Step 5. Calculate the total MPN value and the total 95% confidence limit values for each QC
and PE sample by multiplying the values per milliliter by S and dividing by 0.4.
REDUCTION OF CYTOTOXICITY IN SAMPLE CONCENTRATES
The procedure described in this section may result in a significant liter reduction and
should be applied only to inocula known to be or expected to be toxic.
Media and Reagents:
1. Washing solution.
Dissolve 8.5 g ofNaCl in a final volume of 980 mL ofdH20. Autoclave the solution at
121 °Cfor 15 min. Cool to room temperature. Add 20 mL serum to the sterile salt solution.
Mix thoroughly. Store the washing solution at 4 °Cfor up to three months or at -20 °C.
The volume of the NaCl washing solution required will depend on the number of bottles to
be processed and the cell surface area of the vessels used for the quantal assay.
6Use significant figures when reporting all results throughout the protocol (see
APHA, 1995, p. 1-17).
VIII-28
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Procedure for Cytotoxicity Reduction:
Step 1. Decant and save the inoculum from inoculated cell culture vessels after the adsorp-
tion period (Step 5 of Sample Inoculation and CPE Development). Add 0.25 mL of the
washing solution for each cm2 of cell surface area into each vessel.
Warm the washing solution to 36.5 ± 1 °C before placing on cell monolayer. Add the
washing solution to the side of the cell culture vessel opposite the cell monolayer. Avoid
touching any pipetting devices used to the inside rim of the culture vessels to avert the
possibility of transporting contaminants to the remaining vessels.
The inocula saved after the adsorption period should be stored at -70 °Cfor subsequent
treatment and may be discarded when cytotoxicity is successfully reduced.
Step 2. Gently rock the washing solution gently across the cell monolayer a minimum of two
times. Decant and discard the spent washing solution without disturbing the cell monolayer.
It may be necessary to rock the washing solution across the monolayer more than twice if
sample is oily and difficult to remove from the cell monolayer surface.
Step 3. Continue with Step 7 of the procedure for Sample Inoculation and CPE Develop-
ment.
If this procedure fails to reduce cytotoxicity with a particular type of water sample,
backup samples may be diluted 1:2 to 1:4 before repeating the procedure. This dilution
requires that two to four times more culture vessels be used. Dilution alone may sufficiently
reduce cytotoxicity of some samples without washing. Alternatively, the changing of liquid
maintenance medium at the first signs of cytotoxicity may prevent further development.
Determine cytotoxicity from the initial daily macroscopic examination of the appearance
of the cell culture monolayer by comparing the negative control from Step 4ai and the positive
control from Step 4aii of the procedure for Sample Inoculation and CPE Development with
the test samples from Step 4b). Cytotoxicity should be suspected when the cells in the test
sample develop CPE before its development on the positive control.
VIII-29
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PART 4 — CELL CULTURE PREPARATION AND MAINTENANCE
PREPARATION OF CELL CULTURE MEDIUM
General Principles:
1. Equipment care — Carefully wash and sterilize equipment used for preparing media
before each use.
2. Disinfection of work area — Thoroughly disinfect surfaces on which the medium
preparation equipment is to be placed.
3. Aseptic technique — Use aseptic technique when preparing and handling media or
medium components.
4. Dispensing filter-sterilized media — To avoid post-filtration contamination, dispense
filter-sterilized media into storage containers through clear glass filling bells in a microbiolog-
ical laminar flow hood. If a hood is unavailable, use an area restricted solely to cell culture
manipulations.
5. Coding media — Assign a lot number to and keep a record of each batch of medium or
medium components prepared. Place the lot number, the date of preparation, the expiration
date, and the initials of the person preparing the medium on each bottle.
6. Sterilization of NaHCO3-containing solutions — Sterilize media and other solutions that
contain NaHCO3 by positive pressure filtration.
Negative pressure filtration of such solutions increases the pH and reduces the buffering
capacity.
1. Antibiotic solutions prepared in-house must be filter sterilized with 0.22 jim membrane
filters. It is important that the recommended antibiotic levels not be exceeded during the
planting of cells, as cultures are particularly sensitive to excessive concentrations at this stage.
Antibiotic stock solutions should be placed in screw-capped containers and stored at -20°C
until needed. Once thawed, they may be refrozen; however, repeated freezing and thawing of
these stock solutions should be avoided by freezing them in quantities that are sufficient to
support a week's cell culture work.
Apparatus and Materials:
1. Glassware, Pyrex (Corning Product No. 1395).
Storage vessels must be equipped with airtight closures.
VIII-30
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2. Disc filter holders — 142 mm or 293 mm diameter (Millipore Product No. YY30 142 36
and YY30293 16).
Use only positive pressure type filter holders.
3. Sterilizing filter stacks — 0.22 |im pore size (Millipore Product No. GSWP 142 50 and
GSWP 293 25). Fiberglass prefilters (Millipore APIS 142 50 or APIS 293 25, and AP20 142
50 or AP20 293 25).
Stack AP20 and AP15 prefilters and 0.22 jum membrane filter into a disc filter holder with
AP20 prefilter on top and 0.22 jum membrane filter on bottom.
Always disassemble the filter stack after use to check the integrity of the 0.22 ^m filter.
Re filter any media filtered with a damaged stack.
4. Positively-charged cartridge filter — 10 inch (Zeta plus TSM, Cuno Product No.
45134-01-600P). Cartridge housing with adaptor for 10 inch cartridge (Millipore Product No.
YY16 012 00).
5. Culture capsule filter (Gelman Sciences Product No. 12170).
6. Cell culture vessels — Pyrex, soda or flint glass or plastic bottles and flasks or roller
bottles (e.g., Brockway Product No. 1076-09A, 1925-02, Corning Product No. 25100-25,
25110-75, 25120-150, 25150-1750).
Vessels must be made from clear glass or plastic to allow observation of the cultures and
be equipped with airtight closures. Plastic vessels must be treated by the manufacturer to
allow cells to adhere properly.
1. Screw caps, black with rubber liners (Brockway Product No. 24-414).
Caps for larger culture bottles usually supplied with bottles.
8. Roller apparatus (Bellco Glass Product No. 7730).
Required only if roller bottles are used for maintenance of stock cultures.
9. Waterbath set at 56 ± 1 °C.
10. Light microscope, with conventional light source, equipped with lenses to provide 40X,
100X, and 400X total magnification.
11. Inverted light microscope equipped with lenses to provide 40X, 100X, and 400X total
magnification.
12. Phase contrast counting chamber (hemocytometer) (Curtin Matheson Scientific Product
No. 158-501).
13. Conical centrifuge tubes — 50 and 250 mL capacity.
VIII-31
-------
14. Rack for tissue culture tubes (Bellco Product No. 2028).
15. Bottles, aspirator-type with tubing outlet — 2,000 mL capacity.
Bottles for use with pipetting machine.
16. Storage vial s — 2 mL capacity.
Vials must withstand temperatures to -70 °C.
Media and Reagents:
1. Sterile fetal calf, gamma globulin-free newborn calf or iron-supplemented calf serum,
certified free of viruses, bacteriophage and mycoplasma.
Test each lot of serum for cell growth and toxicity before purchasing. Serum should be
stored at -20 °Cfor long-term storage. Upon thawing, each bottle must be heat-inactivated in
a waterbath set at 56 ± 1 °Cfor 30 min and stored at 4 °Cfor short term use.
2. Trypsin, 1:250 powder (Difco Laboratories Product No. 0152-15-9) ortrypsin, 1:300
powder (Becton Dickinson Microbiology Systems Product No. 12098).
3. EDTA (Fisher Scientific Product No. S657-500).
4. Fungizone (amphotericin B, Sigma Product No. A-9528), penicillin G (Sigma Product
No. P-3032), streptomycin sulfate (ICN Biomedicals Product No. 100556), tetracycline
hydrochloride (ICN Biomedicals Product No. 103011).
Use antibiotics of at least tissue culture grade.
5. Eagle's minimum essential medium (MEM) with Hanks' salts and L-glutamine, without
sodium bicarbonate (Life Technologies Product No. 410-1200).
6. Leibovitz's L-15 medium with L-glutamine (Life Technologies Product No. 430-1300).
7. Trypan blue (Sigma Chemical Product No. T-6146).
8. Dimethyl sulfoxide (DMSO; Sigma Chemical Product No. D-2650).
Media Preparation Recipes:
The conditions specified by the supplier for storage and expiration dates of commercially
available media should be strictly observed.
1. Procedure for the preparation of 10 L of EOT A-trypsin.
The procedure described is used to dislodge cells attached to the surface of culture bottles
and flasks. This reagent, when stored at 4 °C, retains its working strength for at least four
VIII-32
-------
months. The amount of reagent prepared should be based on projected usage over a four
month period.
Step a. Add 30 g of trypsin (1:250) or 25 g of trypsin (1:300) to 2 L of dH2O in a six
liter flask containing a three inch stir bar. Place the flask onto a magnetic stirrer and mix
the trypsin solution rapidly for a minimum of 1 h.
The trypsin remains cloudy.
Step b. Add 4 L of dH2O and a three-inch stir bar into a 20 liter clear plastic carboy.
Place the carboy onto a magnetic stirrer and stir at a speed sufficient to develop a vortex
while adding the following chemicals: 80 g NaCl, 12.5 g EDTA, 50 g glucose, 11.5 g
Na2HPO4 • 7H2O, 2.0 g KC1, and 2.0 g KH2PO4.
Each chemical does not have to be completely dissolved before adding the next one.
Step c. Add an additional 4 L dH2O to the carboy and continue mixing until all the
chemicals are completely dissolved.
Step d. Add the 2 L of trypsin from Step 2a to the solution from Step 2c and mix for a
minimum of 1 h. Adjust the pH of the EDTA-trypsin reagent to 7.5 - 7.7.
Step e. Filter the reagent under pressure through a filter stack and store the filtered
reagent in tightly stoppered or capped containers at 4°C.
The cartridge prefilter (Item 4 of Apparatus and Materials) can be used in line with
the culture capsule sterilizing filter (Item 5) as an alternative to a filter stack (Item 3).
2. Procedure for the preparation of 10 L of MEM/L-15 medium.
Step a. Place a three inch stir bar and 4 L of dH2O into a 20 liter clear plastic carboy.
Step b. Place the carboy onto a magnetic stirrer. Stir at a speed sufficient to develop a
vortex and then add the contents of a five liter packet of L-15 medium to the carboy.
Rinse the medium packet with three washes of 200 mL each of dH2O and add the rinses
to the carboy.
Step c. Mix until the medium is evenly dispersed.
L-15 medium may appear cloudy as it need not be totally dissolved before proceed-
ing to Step d.
Step d. Add 3 L of dH2O to the carboy and the contents of a five liter packet of MEM
medium to the carboy. Rinse the MEM medium packet with three washes of 200 mL
each of dH2O and add the rinses to the carboy. Add 800 mL of dH2O and 7.5 g of
NaHCO3 and continue mixing for an additional 60 min.
VIII-33
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Step e. Transfer the MEM/L-15 medium to a pressure can and filter under positive
pressure through a 0.22 jim sterilizing filter. Collect the medium in volumes appropriate
for the culturing of BGM cells (e.g., 900 mL in a one liter bottle) and store in tightly
stoppered or capped containers at 4°C for up to two months.
Note that the volume of the MEM/L-15 medium adds up to only 9 L to allow for the
addition of serum to a final concentration of 10%.
3. Procedure for preparation of 100 mL of trypan blue solution.
The procedure is used in the direct determination of the viable cell counts of the BGM
stock cultures. As trypan blue is on the U.S. EPA suspect carcinogen list, particular care
should be taken in its preparation and use so as to avoid skin contact or inhalation. The
wearing of rubber gloves during preparation and use is recommended.
Step a. Add 0.5 g of trypan blue to 100 mL of dH2O in a 250 mL flask. Swirl the flask
until the trypan blue is completely dissolved.
Step b. Sterilize the solution by autoclaving at 121 °C for 15 min and store in a screw-
capped container at room temperature.
4. Preparation of 100 mL of penicillin-streptomycin stock solution containing 100,000
units/mL of penicillin and 100,000 |ig/mL of streptomycin.
Step a. Add 10,000,000 units of penicillin G and 10 g of streptomycin sulfate to a 250
mL flask containing 100 mL of dH2O. Mix the contents of the flasks on magnetic stirrer
until the antibiotics are dissolved.
Step b. Sterilize the antibiotics by filtration through a 0.22 jim membrane filter and dis-
pense in 10 mL volumes into screw-capped containers.
5. Preparation of 50 mL of tetracycline stock solution.
Step a. Add 1.25 g of tetracycline hydrochloride powder and 3.75 g of ascorbic acid to
a 125 mL flask containing 50 mL of dH2O. Mix the contents of the flask on a magnetic
stirrer until the antibiotic is dissolved.
Step b. Sterilize the antibiotic by filtration through a 0.22 jim membrane filter and
dispense in 5 mL volumes into screw-capped containers.
6. Preparation of 25 mL of amphotericin B (fungizone) stock solution.
Step a. Add 0.125 g of amphotericin B to a 50 mL flask containing 25 mL of dH2O.
Mix the contents of the flask on a magnetic stirrer until the antibiotic is dissolved.
VIII-34
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Step b. Sterilize the antibiotic by filtration through a 0.22 jim membrane filter and
dispense in 2.5 mL volumes into screw-capped containers.
PREPARATION AND PASSAGE OF BGM CELL CULTURES
A microbiological biosafety cabinet should be used to process cell cultures. If a hood is
not available, cell cultures should be prepared in controlled facilities used for no other
purposes. Viruses or other microorganisms must not be transported, handled, or stored in
rooms used for cell culture transfer.
Vessels and Media for Cell Growth:
1. The BGM cell line grows readily on the inside surfaces of glass or specially treated, tissue
culture grade plastic vessels. Flat-sided, glass bottles (16 to 32 oz or equivalent growth area),
75 or 150 cm2 plastic cell culture flasks, and 690 cm2 glass or 850 cm2 plastic roller bottles are
usually used for the maintenance of stock cultures. Flat-sided bottles and flasks that contain
cells in a stationary position are incubated with the flat side (cell monolayer side) down. If
available, roller bottles and roller apparatus units are preferable to flat-sided bottles and flasks
because roller cultures require less medium than flat-sided bottles per unit of cell monolayer
surface area. Roller apparatus rotation speed should be adjusted to one-half revolution per
minute to ensure that cells are constantly bathed in growth medium.
2. Growth and maintenance media should be prepared on the day they will be needed.
Prepare growth medium by supplementing MEM/L-15 medium with 10% serum and antibiot-
ics (100 mL of serum, 1 mL of penicillin-streptomycin stock, 0.5 mL of tetracycline stock and
0.2 mL of fungizone stock per 900 mL of MEM/L-15). Prepare maintenance medium by
supplementing MEM/L-15 with antibiotics and 2% or 5% serum (20 or 50 mL of serum,
antibiotics as above for growth medium and 80 or 50 mL of dH2O, respectively). Use
maintenance media with 2% serum for CPE development.
General Procedure for Cell Passage:
Pass stock BGM cell cultures at approximately seven day intervals using growth medium.
Step 1. Pour spent medium from cell culture vessels, and discard the medium.
A gauze-covered beaker may be used to collect spent medium to prevent splatter.
Autoclave all media that have been in contact with cells or that contain serum before discard-
ing.
Step 2. Add a volume of warm EDTA- trypsin reagent equal to 40% of the volume of
medium that was discarded in Step 1.
See Table VHI-lfor the amount of reagents required for commonly used vessel types.
Warm the EDTA-trypsin reagent to 36.5 ± 1 °C before placing it onto cell monolayers.
VIII-35
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Table VIII-1. Guide for Preparation of BGM Stock
Cultures
Vessel Type
16 oz glass
flat bottles
32 oz glass
flat bottles
75 cm2 plastic
flat flask
150 cm2 plastic
flat flask
690 cm2 glass
roller bottle
850 cm2 plastic
roller bottle
Volume of
EDTA-Trypsin
(mL)
10
20
12
24
40
48
Volume of
Medium (mL)a
25
50
30
60
100
120
Total No. Cells
to Plate
per Vessel
2.5 xlQ6
5.0 xlQ6
3.0 xlQ6
6.0 xlQ6
7.0 xlQ6
8.0 xlQ7
aSerum requirements: growth medium contains 10% serum;
maintenance medium contains 2-5% serum. Antibiotic requirements:
penicillin-streptomycin stock solution, 1.0 mL/liter; tetracycline stock
solution, 0.5 mL/liter; fungizone stock solution, 0.2 mL/liter.
Step 3. Allow
the EDTA-
trypsin reagent
to remain in
contact with
cells at room
temperature un-
til the cell
monolayer can
be shaken loose
from the inner
surface of the
cell culture ves-
sel.
To prevent
cell damage, the
EDTA-trypsin
reagent should
remain in con-
tact with the
cells no longer
than 5 min.
Step 4. Pour
the suspended
cells into centri-
fuge tubes or bottles.
To facilitate collection and resuspension of cell pellets, use tubes or bottles with conical
bottoms. Centrifuge tubes and bottles used for this purpose must be able to withstand the
g-force applied.
Step 5. Centrifuge cell suspension at 1,000 xg for 10 min to pellet cells. Pour off and
discard the supernatant.
Do not exceed this speed as cells may be damaged or destroyed.
Step 6. Suspend the pelleted cells in growth medium (see Item 2 of Vessels and Media for
Cell Growth) and perform a viable count on the cell suspension according to the Procedure
for Performing Viable Cell Counts section below.
Resuspendpelletedcells in a sufficient volume of medium to allow thorough mixing of the
cells (to reduce sampling error) and to minimize the significance of the loss of the 0.5 mL of
cell suspension required for the cell counting procedure. The quantity of medium used for
resuspending pelleted cells varies from 50 to several hundred milliliters, depending upon the
volume of the individual laboratory's need for cell cultures.
VIII-36
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Table VIII-2. Preparation of Virus Assay Cell
Cultures
Vessel Type
1 oz glass bottle
25 cm2 plastic flask
6 oz glass bottle
75 cm2 plastic flask
16 mm x 150 mm tubes
Volume of
Medium* (mL)
4
10
15
30
2
Final Cell Count
per Vessel
9.0 xio5
3.5 xio6
5.6 xio6
1.0 xio7
4.0 xio4
* Serum requirements: growth medium contains 10% serum.
Antibiotic requirements: penicillin- streptomycin stock solution, 1.0
mL/liter; tetracycline stock solution, 0.5 mL/liter; fungizone stock
solution, 0.2 mL/liter.
Step 7. Dilute
the cell suspen-
sion to the appro-
priate final cell
concentration
with growth me-
dium and
dispense into cell
culture vessels
with a pipet, a
Cornwall syringe
or a Brewer- type
pipetting machine
dispenser.
Calculate the
dilution factor
requirement using
the cell count and
the cell and volume parameters given in Table VIII-1 for stock cultures and in Table VIII-2
for virus assay cultures.
As a general rule, the BGM cell line should be split at a 1:2 ratio for passages 117 to 150
and a 1:3 ratio for passages 151 to 250. To plant two hundred 25 cm2 cell culture flasks
weekly from cells between 151 and 250 passages would require the preparation of six roller
bottles (surface area of 690 cm2 each): The contents of two to prepare the next batch of six rol-
ler bottles and the contents of the other four to prepare the 25 cm2 flasks.
Step 8. Except during handling operations, maintain BGM cells at 36.5 ± 1 °C in airtight cell
culture vessels.
Step 9. Replace growth medium with maintenance medium containing 2% serum when cell
monolayers become 95 to 100% confluent (usually three to four days after seeding with an
appropriate number of cells). Replace growth medium that becomes acidic before the mono-
layers become 95 to 100% confluent with maintenance medium containing 5% serum. The
volume of maintenance medium should equal the volume of the discarded growth medium.
Procedure For Performing Viable Cell Counts:
Step 1. Add 0.5 mL of cell suspension (or diluted cell suspension) to 0.5 mL of 0.5% trypan
blue solution in a test tube.
To obtain an accurate cell count, the optimal total number of cells per hemocytometer
section should be between 20 and 50. This range is equivalent to between 6.0 * 105 and 1.5 x
106 cells per mL of cell suspension. Thus, a dilution of 1:10 (0.5 mL of cells in 4.5 mL of
growth medium) is usually required for an accurate count of a cell suspension.
VIII-37
-------
Step 2. Disperse cells by repeated pipetting.
Avoid introducing air bubbles into the suspension, because air bubbles may interfere with
subsequent filling of the hemocytometer chambers.
Step 3. With a capillary pipette, carefully fill a hemocytometer chamber on one side of a
slip-covered hemocytometer slide. Rest the slide on a flat surface for about 1 min to allow the
trypan blue to penetrate the cell membranes of nonviable cells.
Do not under or overfill the chambers.
Step 4. Under 100X total magnification, count the cells in the four large corner sections and
the center section of the hemocytometer chamber.
Include in the count cells lying on the lines marking the top and left margins of the
sections, and ignore cells on the lines marking the bottom and right margins. Trypan blue is
excluded by living cells. Therefore, to quantify viable cells, count only cells that are clear in
color. Do not count cells that are blue.
Step 5. Calculate the average number of viable cells in each mL of cell suspension by
totaling the number of viable cells counted in the five sections, multiplying this sum by 2000,
and where necessary, multiplying the resulting product by the reciprocal of the dilution.
PROCEDURE FOR PRESERVATION OF BGM CELL LINE
An adequate supply of frozen BGM cells must be available to replace working cultures
that are used only periodically or become contaminated or lose virus sensitivity. Cells have
been held at -70 °Cfor more than 15 years with a minimum loss in cell viability.
Preparation of Cells for Storage:
The procedure described is for the preparation of 100 cell culture vials. Cell concentra-
tion must be at least 2 x 106 per mL.
The actual number of vials to be prepared should be based upon line usage and the
anticipated time interval requirement between cell culture start-up and full culture production.
Step 1. Prepare cell storage medium by adding 10 mL of DMSO to 90 mL of growth
medium (see Item 2 of Vessels and Media for Cell Growth). Sterilize the resulting cell
storage medium by passage through a 0.22 jim sterilizing filter.
Collect sterilized medium in a 250 mL flask containing a stir bar.
Step 2. Harvest BGM cells from cell culture vessels as directed in Steps 1 to 5 of General
Procedures for Cell Passage. Count the viable cells as described above and resuspend them
in the cell storage medium at a concentration of at least 2 x io6 cells per mL.
Step 3. Place the flask containing suspended cells on a magnetic stirrer and slowly mix for
30 min. Dispense 1 mL volumes of cell suspension into 2 mL capacity vials.
VIII-38
-------
Procedure for Freezing Cells:
The freezing procedure requires slow cooling of the cells with the optimum rate of-1 °C
per min. A slow cooling rate can be achieved using the following method or by using the
recently available freezing containers (e.g., Nalge Product No. 5100-0001) as recommended
by the manufacturers.
Step 1. Place the vials in a rack and place the rack in refrigerator at 4°C for 30 min, then in a
-20 °C freezer for 30 min, and finally in a -70 °C freezer overnight. The transfers should be
made as rapidly as possible.
To allow for more uniform cooling, wells adjoining each vial should remain empty.
Step 2. Rapidly transfer vials into boxes or other containers for long-term storage.
To prevent substantial loss of cells during storage, temperature of cells should be kept
constant after -70°C has been achieved.
Procedure for Thawing Cells:
Cells must be thawed rapidly to decrease loss in cell viability.
Step 1. Place vials containing frozen cells into a 36.5 ± 1 °C water bath and agitate vigorous-
ly by hand until all ice has melted. Sterilize the outside surface of the vials with 0.5% I2 in
70% ethanol.
Step 2. Add BGM cells to either 6 oz tissue culture bottles or 25 cm2 tissue culture flasks
containing an appropriate volume of growth medium (see Table VIII-2). Use two vials of
cells for 6 oz bottles and one vial for 25 cm2 flasks.
Step 3. Incubate BGM cells at 36.5 ± 1 °C. After 18 to 24 h replace the growth medium with
fresh growth medium and then continue the incubation for an additional five days. Pass and
maintain the new cultures as directed above.
VIII-39
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PART 5 — STERILIZATION AND DISINFECTION
GENERAL GUIDELINES
1. Use aseptic techniques for handling test waters, eluates and cell cultures.
2. Sterilize apparatus and containers that will come into contact with test waters and all
solutions that will be added to test waters unless otherwise indicated. Thoroughly clean all
items before final sterilization using laboratory standard operating procedures.
3. Sterilize all contaminated materials before discarding.
4. Disinfect all spills and splatters.
STERILIZATION TECHNIQUES
Solutions:
1. Sterilize all solutions, except those used for cleansing, standard buffers, hydrochloric acid
(HC1), sodium hydroxide (NaOH), and disinfectants by autoclaving them at 121 °C for at least
15 min.
The HCl and NaOH solutions and disinfectants used are self-sterilizing. When autoclav-
ing buffered beef extract, use a vessel large enough to accommodate foaming.
Autoclavable Glassware, Plasticware, and Equipment:
Water speeds the transfer of heat in larger vessels during autoclaving and thereby speeds
the sterilization process. AdddH2O to vessels in quantities indicated in Table VIII-3. Lay
large vessels on their sides in the autoclave, if possible, to facilitate the displacement of air in
the vessels by flowing steam.
1. Cover the openings into autoclavable glassware, plasticware, and equipment loosely with
aluminum foil before autoclaving. Autoclave at 121 °C for at least 30 min.
Glassware may also be sterilized in a dry heat oven at a temperature of 170 °Cfor at least
Ih.
2. Sterilize stainless steel vessels (dispensing pressure vessel) in an autoclave at 121 °C for at
least 30 min.
Vent-relief valves on vessels so equipped must be open during autoclaving and closed
immediately when vessels are removed from autoclave.
3. Presterilize 1MDS filter cartridges and prefilter cartridges by wrapping the filters in Kraft
paper and autoclaving at 121 °C for 30 min.
VIII-40
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Table VIII-3. Water Quantity to be Added to
Vessels Before Autoclaving
Vessel Size (liter)
2 and 3
4
8
24
54
Quantity of dH2O (mL)
25
50
100
500
1000
4. Sterilize instruments,
such as scissors and forceps,
by immersing them in 95%
ethanol and flaming them be-
tween uses.
Chlorine Sterilization:
Sterilize pumps, plastic-
ware (filter housings) and
tubing that cannot withstand
autoclaving, and vessels that
are too large for the
autoclave by chlorination.
Prefilters, but not 1MDS fil-
ters, may be presterilized with chlorine as an alternative to autoclaving. Filter apparatus
modules should be disinfected by sterilization and then cleaned according to laboratory
standard operating procedures before final sterilization.
1. Media and Reagents
a. 0.1% chlorine (HOC1) — add 19 mL of household bleach (Clorox, The Clorox Co.)
to 900 mL of dH2O and adjust the pH of the solution to 6-7 with 1 M HC1. Bring to 1 liter
with dH2O.
2. Procedures
Ensure that the solutions come in full contact with all surfaces when performing these
procedures.
a. Sterilize filter apparatus modules, injector tubing and plastic bags for transporting
injector tubing by recirculating or immersing the items in 0.1% chlorine for 30 min.
Drain the chlorine solution from objects being sterilized. Dechlorinate using a solution
containing 2.5 mL of 2% sterile sodium thiosulfate per liter of sterile dH2O.
b. Thoroughly rinse pH electrodes after each use to remove particulates. Sterilize
before and after each use by immersing the tip of the electrode in 0.1% chlorine for at
least 1 min. Dechlorinate the electrode as in Step 2a above. Rinse with sterile dH2O.
PROCEDURE FOR VERIFYING STERILITY OF LIQUIDS
Do not add antibiotics to media or medium components until after their sterility has been
demonstrated. The BGM cell line used should be checked every six months for mycoplasma
contamination according to test kit instructions. Cells that are contaminated should be
discarded.
VIII-41
-------
Media and Reagents:
1. Mycoplasma testing kit (Irvine Scientific Product No. T500-000). Use as directed by the
manufacturer.
2. Thiogly coll ate medium (Difco Laboratories Product No. 0257-01-9). Prepare broth
medium as directed by the manufacturer.
Verifying Sterility of Small Volumes of Liquids:
Step 1. Inoculate 1 mL portions of the material to be tested for sterility into tubes containing
9 mL of thioglycollate broth by stabbing the inoculum into the broth. Incubate at 36.5 ± 1 °C.
Step 2. Examine the inoculated broth daily for seven days to determine whether growth of
contaminating organisms has occurred.
Containers holding the thioglycollate medium must be tightly sealed before and after the
medium is inoculated.
Visual Evaluation of Media for Microbial Contaminants:
Step 1. Incubate either the entire stock of prepared media or portions taken during prepara-
tion that represent at least 5% of the final volume at 36.5 ± 1 °C for at least one week before
use.
Step 2. Visually examine and discard any media that lose clarity.
A clouded condition that develops in the media indicates the occurrence of contaminating
organisms.
CONTAMINATED MATERIALS
1. Autoclave contaminated materials for at least 30 min at 121 °C. Be sure that steam can
enter contaminated materials freely.
2. Many commercial disinfectants do not adequately kill enteric viruses. To ensure thorough
disinfection, disinfect spills and other contamination on surfaces with either a solution of 0.5%
iodine in 70% ethanol (5 g I2 per liter) or 0.1% chlorine. The iodine solution has the advantage
of drying more rapidly on surfaces than chlorine, but may stain some surfaces.
VIII-42
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PART 6 — BIBLIOGRAPHY AND SUGGESTED READING
APHA. 1995. Standard Methods for the Examination of Water and Wastewater (A. D. Eaton,
L. S. Clesceri and A. E. Greenberg, ed), 19th Edition. American Public Health Association,
Washington, D.C.
Barren, A. L., C. Olshevsky and M. M. Cohen. 1970. Characteristics of the BGM line of cells
from African green monkey kidney. Archiv. Gesam. Virusforsch. 32:389-392.
Berg, G., R. S. Safferman, D. R. Dahling, D. Berman and C. J. Hurst. 1984. USEPA Manual
of Methods for Virology. U.S. Environmental Protection Agency Publication No. EPA/600/4-
84/013, Cincinnati, OH.
Chang, S. L., G. Berg, K. A. Busch, R. E. Stevenson, N. A. Clarke and P. W. Kabler. 1958.
Application of the "most probable number" method for estimating concentration of animal
viruses by the tissue culture technique. Virology 6:27-42.
Crow, E. L. 1956. Confidence intervals for a proportion. Biometrika. 43:423-435.
Dahling, D. R. and B. A. Wright. 1986. Optimization of the BGM cell line culture and viral
assay procedures for monitoring viruses in the environment. Appl. Environ. Microbiol.
51:790-812.
Dahling, D. R. and B. A. Wright. 1987. Comparison of the in-line injector and fluid propor-
tioner used to condition water samples for virus monitoring. J. Virol. Meth. 18:67-71.
Dahling, D. R., G. Berg and D. Berman. 1974. BGM, a continuous cell line more sensitive
than primary rhesus and African green kidney cells for the recovery of viruses from water.
Health Lab. Sci. 11:275-282.
Dahling, D. R., R. S. Safferman and B. A. Wright. 1984. Results of a survey of BGM cell
culture practices. Environ. Internal 10:309-313.
Eagle, H. 1959. Amino acid metabolism in mammalian cell cultures. Science. 130:432-437.
EPA. 1989. Guidance manual for compliance with the filtration and disinfection requirements
for public water systems using surface water sources. Office of Drinking Water, Washington,
D.C.
Freshney, R. I. 1983. Culture of Animal Cells: A Manual of Basic Technique. AlanR. Liss,
New York, NY.
VIII-43
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Hay, R. J. 1985. ATCC Quality Control Methods for Cell Lines. American Type Culture
Collection, Rockville, MD.
Hurst, C. J. 1990. Field method for concentrating viruses from water samples, pp. 285-295.
In G. F. Craun (ed.), Methods for the Investigation and Prevention of Waterborne Disease
Outbreaks. U.S. Environmental Protection Agency Publication No. EPA/600/1 -90/005a,
Washington, D.C.
Hurst, C. J. 1991. Presence of enteric viruses in freshwater and their removal by the conven-
tional drinking water treatment process. Bull. W.H.O. 69:113-119.
Hurst, C. J. and T. Goyke. 1983. Reduction of interfering cytotoxicity associated with
wastewater sludge concentrates assayed for indigenous enteric viruses. Appl. Environ.
Microbiol. 46:133-139.
Katzenelson, E., B. Fattal and T. Hostovesky. 1976. Organic flocculation: an efficient
second-step concentration method for the detection of viruses in tap water. Appl. Environ.
Microbiol. 32:638-639.
Laboratory Manual in Virology. 1974. 2nd Ed. Ontario Ministry of Health, Toronto,
Ontario, Canada.
Leibovitz, A. 1963. The growth and maintenance of tissue-cell cultures in free gas exchange
with the atmosphere. Amer. J. Hyg. 78:173-180.
Lennette, E. H., D.A. Lennette and E.T. Lennette (ed.). 1995. Diagnostic Procedures for
Viral, Rickettsial and Chlamydial Infections, 7th ed. American Public Health Association,
Washington, D.C.
Malherbe, H. H. andM. Strickland-Cholmley. 1980. Viral Cytopathology. CRC Press. Boca
Raton, FL.
Morris, R. and W. M. Waite. 1980. Evaluation of procedures for recovery of viruses from
water—II detection systems. Water Res. 14:795-798.
Paul, J. 1975. Cell and Tissue Culture. 5th Ed. Churchill Livingstone, London, Great
Britain.
Payment, P. and M. Trudel. 1985. Influence of inoculum size, incubation temperature, and
cell culture density on virus detection in environmental samples. Can. J. Microbiol. 31:977-
980.
VIII-44
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Rovozzo, G. C. and C. N. Burke. 1973. A Manual of Basic Virological Techniques.
Prentice-Hall, Englewood Cliffs, NJ.
Sobsey, M. D. 1976. Field monitoring techniques and data analysis, pp. 87-96. In L. B.
Baldwin, J. M. Davidson and J. F. Gerber (eds.), Virus Aspects of Applying Municipal Waste
to Land. University of Florida, Gainesville, FL.
Sobsey, M. D. 1980. Poliovirus concentration from tap water with electropositive adsorbent
filters. Appl. Environ. Microbiol. 40:201-210.
Thomas, H. A., Jr. 1942. Bacterial densities from fermentation tube tests. J. Amer. Water
Works Assoc. 34:572-576.
Waymouth, C., R. G. Ham and P. J. Chappie. 1981. The Growth Requirements of Vertebrate
Cells In Vitro. Cambridge University Press, Cambridge, Great Britain.
VIII-45
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PART 7 — VENDORS
The vendors listed below represent one possible source for required products. Other vendors
may supply the same or equivalent products.
American Type Culture Collection
12301ParklawnDr.
Rockville, MD 20852
(800)638-6597
Baxter Diagnostics, Scientific Products Div.
1430WaukeganRd.
McGaw Park, IL 60085
(800) 234-5227
BBL Microbiology Systems: products may
be ordered through several major scientific
supply houses
Becton Dickinson Microbiology Systems
250 Schilling Circle
Cockeysville, MD 21030
(410) 771-0100 (Ask for a local distributor)
Bellco Glass
340 Edrudo Rd.
Vineland, NJ 08360
(800)257-7043
Brockway: products may be ordered
through Continental Glass & Plastics
Cincinnati Valve and Fitting Co.
3710 Southern Ave.
Cincinnati, OH 45227
(513)272-1212
Cole-Parmer Instrument Co.
7425 N. Oak Park Ave.
Niles, IL60714
(800)323-4340
Continental Glass & Plastics
841 W. CermakRd.
Chicago, IL 60608
(312)666-2050
Corning: products may be ordered through
most major scientific supply houses
Costar Corp.
7035 Commerce Circle
Pleasanton, CA 94588
(800)882-7711
Cuno, Inc.
400 Research Parkway
Meriden, CT 06450
(800)243-6894
Curtin Matheson Scientific
P.O. Box 1546
Houston, TX 77251
(713) 820-9898
DEMA Engineering Co.
10014 Big Bend Blvd.
Kirkwood,MO63122
(800) 325-3362
Difco Laboratories
P.O. Box 331058
Detroit, MI 48232
(800) 521-0851 (Ask for a local distributor)
Fisher Scientific
711 Forbes Ave.
Pittsburgh, PA 15219
(800) 766-7000
VIII-46
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Gelman Sciences
600 S. Wagner Rd.
Ann Arbor, MI 48103
(800)521-1520
ICN Biomedicals
3300 Hyland Ave.
Costa Mesa, C A 92626
(800)854-0530
Irvine Scientific
2511 Daimler Street
Santa Ana, CA 92705
(800) 437-5706
Life Technologies
P.O. Box 68
Grand Island, NY 14072
(800) 828-6686
Millipore Corp.
397 Williams St.
Marlboro, MA 01752
(800)225-1380
Nalge Co.
P.O. Box 20365
Rochester, NY 14602
(716) 586-8800 (Ask for a local distributor)
Neptune Equipment Co.
520 W. Sharon Rd.
Forest Park, OH 45240
(800) 624-6975
OMEGA Engineering, Inc.
P.O. Box 4047
Stamford, CT 06907
(800) 826-6342
Plast-o-matic Valves, Inc.
1384 Pompton Ave
Cedar Grove, NJ 07009
(201) 256-3000 (Ask for a local distributor)
Parker Hannifin Corp.
Commercial Filters Div.
1515 W. South St., Lebanon, IN 46052
(317)482-3900
Ryan Herco
2509 N. Naomi St.
Burbank, CA91504
(800)848-1141
Sigma Chemical
P.O. Box 14508
St. Louis, MO 63178
(800)325-3010
United States Plastic Corp.
1390NeubrechtRd.
Lima, OH 45801
(800)537-9724
Watts Regulator
Box 628
Lawrence, MA 01845
(508)688-1811
VIII-47
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PART 8 — EXAMPLES
EXAMPLE 1
A source water sample of 211.98 L was collected at the Sampleville Water Works on
5/1/95 and shipped by overnight courier to CEPOR Laboratories. CEPOR Laboratories
processed the sample on 5/2/95. After elution, the pH of the beef extract V eluate was
adjusted to 7.3 with 1 M HC1. The volume of the pH-adjusted eluate, 980 mL, was recorded.
Volumes of 34.3 mL (980 x 0.035) and 98.0 mL (980 x 0.1) were removed for the Coliphage
Assay (Section IX) and for archiving, respectively An Adjusted Total Sample Volume
(ATSV) was then calculated by multiplying 211.98 L x 0.865. An ATSV of 183 L was
recorded on the Virus Data Sheet.
The sample was immediately processed by the Organic Flocculation Concentration
Procedure. Following centrifugation at 4,000 *g, the supernatant was adjusted to pH 7.3 and
passed through a sterilizing filter. A Final Concentrated Sample Volume (FCSV) of 28.0
mL was obtained.
The Assay Sample Volume was calculated using the formula:
ASSAY SAMPLE VOLUME (S) = —— x FCSV
ATSV
where D is the Volume of Original Water Sample Assayed (i.e., 100 L for source water or
1000 L for finished water). Thus the Assay Sample Volume for Sampleville-01 is:
S = 10° llters x 28.0 ml = 15.3 ml
183 liters
The 15.3 mL is the volume of the Final Concentrated Sample that must be inoculated onto
tissue culture and that represents 100 L of the source water.
Two subsamples were prepared from the Final Concentrated Sample Subsample 1
was prepared by placing 0.55 x 15.3 mL = 8.4 mL into a separate container. Subsample 2
was prepared by placing 0.67 x 15.3 mL = 10.2 mL into a third container. Although only 0.5
x 15.3 = 7.65 mL (representing 50 L of source water) must be inoculated onto tissue culture
flasks for each subsample, the factor "0.55" was used for subsample 1 to account for unrecov-
erable losses associated with removing a subsample from its container. The factor "0.67" was
used for subsample 2 to account for losses associated with the container and to provide
additional sample for the preparation of dilutions, if required.
VIII-48
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Subsample 2 and the remaining portions of the Final Concentrated Sample were frozen
at-70°C.
The inoculation volume was calculated to be 15.3 mL +• 20 = 0.76 mL per flask. To
make the inoculation procedure more convenient, it was decided to dilute subsample 1 so that
1.0 mL of inoculum contained an amount of subsample 1 equal to the inoculum volume. To
do this, 10.5 x (1.00 - 0.76) = 2.52 mL of 0.15 M NajHPC^ • 7H2O, pH 7.3, was added to 10.5
x 0.76 = 7.98 mL of subsample 1. One milliliter of diluted subsample 1 was then inoculated
onto each often 25 cm2 flasks of BGM cells at passage 123. A negative control was prepared
by inoculating a flask with 1.0 mL of 0.15 M Na2HPO4 • 7H2O, pH 7.3. A positive control
was prepared by inoculating a flask with 1.0 mL of 0.15 M Na2HPO4 • 7H2O, pH 7.3 contain-
ing 200 PFU/mL of attenuated poliovirus type 3. Following adsorption, 9.0 mL of mainte-
nance medium was added and the cultures were incubated at 36.5 °C. These cultures and those
described below were observed for CPE as described in the protocol and positive cultures were
frozen when 75% of a flask showed signs of CPE.
On May 9th five flasks inoculated with subsample 1 and the positive control showed
signs of CPE. Because fewer than eight flasks inoculated with subsample 1 showed CPE, 10
additional 25 cm2 flasks of BGM cells at passage 124 were inoculated with 1.0 mL each of
subsample 2 diluted in the same manner as subsample 1. Another negative control and
positive control were also prepared and inoculated.
By May 16th a total of seven flasks inoculated with subsample 1 showed signs of CPE.
The flasks that had not been previously frozen were now frozen at -70°C and then all flasks
were thawed. Several milliliters of fluid from each of the eight positive flasks (seven samples
plus the positive control) were passed through a sterilizing filter. Twelve flasks of BGM cells
at passage 125 were inoculated with one milliliter of the supernatant from either negative
cultures or from filtered positive cultures.
By May 23rd a total of five flasks from subsample 2 showed signs of CPE. All flasks
were frozen, thawed and then passaged as described for subsample 1 using BGM cells at
passage 126.
By May 30th only six flasks from the second passage of subsample 1 and the positive
control showed CPE. Thus one culture from the 1 st passage failed to confirm in the second
pass and a value of 6 was recorded in the Number of Replicates with CPE column of the
Total Culturable Virus Data Sheet The flasks were then discarded
On June 6th seven flasks (the five original plus two new flasks) from the second passage
of subsample 2 demonstrated CPE. The two new flasks and controls were frozen at -70°C,
thawed and passaged a third time as described above using BGM cells at passage 127.
All other flasks were discarded.
VIII-49
-------
By June 12 the positive control and the two third passage flasks had developed CPE. All
flasks were discarded at this time (the flasks would have been examined until 6/20 if at least
one had remained negative). A value of 7 was recorded into the Number of Replicates with
CPE column of the Total Cultivable Virus Data Sheet
The MPN software program supplied by the U.S. EPA was used to calculate the
MPN/mL and 95% confidence limit values. "I. SIZE OF INOCULUM VOLUME (mL)" on
the main screen was changed from 1 to 0.76. "A. PROCEED WITH DATA INPUT" was
pressed followed by "ENTER" to overwrite the existing output file. Alternatively, "NO"
could have been entered and the output file renamed. The number of positive replicates, "13,"
was then entered. Following the calculation by the program, the MPN and 95% Confidence
Limit values were recorded onto the Quantitation of Total Culturable Virus Data Sheet.
The program was exited by pressing "I. EXIT THE PROGRAM."
The MPN per 100 liter value (M,) was calculated according to the formula:
mS = 100 x 1.38 x 15.3 = 21 l
D 100
where Mm is the MPN value per milliliter from the Quantitation of Total Culturable Virus
Data Sheet, S is the Assay Sample Volume and D is the Volume of Original Water Sample
Assayed (S and D are obtained from the Virus Data Sheet).
The Lower 95% Confidence Limit per 100 liter (CL^ was calculated according to the
formula:
S 100 x Q.7Q x 15.3
D 100
where CLlm is the lower 95% confidence limit per milliliter from the Quantitation of Total
Culturable Virus Data Sheet.
The Upper 95% Confidence Limit per 100 liter (CLU) was calculated according to the
formula:
= 100 x 2.27 x 15.3
D 100
VIII-50
-------
where CLum is the upper 95% confidence limit per milliliter from the Quantitation of Total
Culturable Virus Data Sheet.
VIII-51
-------
SAMPLE DATA SHEET
SAMPLE NUMBER: Sampleville-01
UTILITY NAME: Sampleville Water Works
UTILITY ADDRESS: 1 Water Street
CITY: Sampleville STATE: OH ZIP: 45999
SAMPLER'S NAME: Mr. Brian Hall
WATER TEMPERATURE: 23.5 °C TURBIDITY: 3.6 NTU
WATER pH: 7.8
ADJUSTED WATER pH: NA
THIOSULFATE ADDED: (CHECK) _YES .XNO
INIT. METER READING: 6048.10 CHECK UNITS: .X gallons .ft3
date: 5/1/95 time: 9am
FINAL METER READING: 6104.10 CHECK UNITS: .X gallons .ft3
date: 5/1/95 time: 9:30 am
TOTAL SAMPLE VOLUME: 211.98 L
(Final-Initial meter readings x 3.7854 (for readings in gallons)
or x 28.316 (for readings in ft3))
SHIPMENT DATE: 5/1/95
CONDITION ON ARRIVAL: Cold/Not frozen
COMMENTS:
VIII-52
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VIRUS DATA SHEET
SAMPLE NUMBER: SAMPLEVILLE-01
ANALYTICAL LABORATORY NAME: CEPOR LABORATORIES
ANALYTICAL LABORATORY ADDRESS: 42 RUECKERT ST.
CITY: CINCINNATI STATE: OH ZIP: 45219
ADJUSTED TOTAL SAMPLE VOLUME (ATSV):
. i
183 L
DATEELUTED: 5/2/95
TIME: 10am
ELUATE VOLUME RECOVERED:
980 mL
VOLUME OF ELUATE ARCHIVED:
98.0 mL
DATE CONCENTRATED:
5/2/95
TIME:
1 pm
FINAL CONCENTRATED SAMPLE VOLUME (FCSV):
28.0 mL
ASSAY SAMPLE VOLUME (S):
15.3 mL
VOLUME OF ORIGINAL WATER SAMPLE
ASSAYED (D):
100 L2
INOCULUM VOLUME:
0.76 mL
DATES ASSAYED
BY CPE:
1st Passage
2nd Passage
3rd Passage
(If necessary)
Subsample 1:
Subsample 2:
5/2/95
5/9/95
MPN/100 L3: 21
5/16/95
5/23/95
6/6/95
95% CONFIDENCE LIMITS
LOWER: 11 UPPER: 35
COMMENTS:
ANALYST: E.G. Moore
JEnter the Total Sample Volume times 0.965 if a coliphage sample is taken, times 0.9 if
archiving is required, times 0.865 if a coliphage sample is taken and archiving is
required or times 1 if a coliphage sample is not taken and archiving is not required.
2Must be at least 100 L for source water and 1000 L for finished water.
3Value calculated from the Quantitation of Total Culturable Virus form as described in
the Virus Quantitation section of Part 3.
VIII-53
-------
TOTAL CULTURABLE VIRUS DATA SHEET
SAMPLE #: Sampleville-01
Sample
1st Passage
Neg. Cont.
Pos. Cont.
Undiluted
1:5 Dil.
1:25 Dil.
2nd Passage1
Neg. Cont.
Pos. Cont.
Undiluted
1:5 Dil.
1:25 Dil.
3rd Passage2
Neg. Cont.
Pos. Cont.
Undiluted
1:5 Dil.
1:25 Dil.
Total Number of Replicates
Subsample 1
Inoculated
1
1
10
1
1
10
Without
CPE
1
0
3
1
0
4
With CPE
0
1
7
0
1
6
Subsample 2
Inoculated
1
1
10
1
1
10
1
1
2
Without
CPE
1
0
5
1
0
3
1
0
0
With CPE
0
1
5
0
1
7
0
1
2
1A portion of medium from each 1st passage vessel, including controls, must be repas-
saged for conformation. The terms "Undiluted," "1:5 Dilution" and "1:25 Dilution"
under the 2nd and 3rd Passage headings refer to the original sample dilutions for the
1st passage. If higher dilutions are used, record the data from the three highest
dilutions showing positive results and place the actual dilution amount in the sample
column.
2Samples that were negative on the first passage and positive on the 2nd passage must
be passaged a third time for conformation. If a third passage is required, all controls
must be passaged again.
VIII-54
-------
QUANTITATION OF TOTAL CULTURABLE VIRUS DATA SHEET
SAMPLE NUMBER: Sampleville-01
Sample
Number
Replicates
inoculated
Number
with CPE
Undiluted Samples
Subsample 1
Subsample 2
Total Undiluted
10
10
20
6
7
13
Subsample 2 results (Dilutions Required)
Undiluted
1:5 Dilution
1:25 Dilution
MPN/mL1
1.38
95% Confidence
Limits
Lower
0.70
Upper
2.27
*Use the values recorded in the Total Undiluted row to calculate the MPN/mL result
and confidence limits when dilutions are not required. If dilutions are required, base
the calculation upon the values recorded in the Undiluted, 1:5 Diluted and 1:25 Diluted
rows for subsample 2. If higher dilutions are used for subsample 2, record the data
from the three highest dilutions showing positive results and place the actual dilution
amount in the sample column. The MPN/mL and 95% Confidence Limit values must
be obtained using the computer program supplied by the U.S. EPA.
VIII-55
-------
EXAMPLE 2
A source water sample of 200.63 L was collected at the Sampleville Water Works on
6/5/95 and shipped by overnight courier to CEPOR Laboratories. CEPOR Laboratories
processed the sample on 6/6/95. After elution, the pH was adjusted to 7.3. A volume of 985
mL of pH-adjusted eluate was obtained and 34.5 mL (985 mL x 0.035) was removed for the
Coliphage Assay (Section IX). Archiving was not required. An Adjusted Total Sample
Volume of 194 L (200.63 L x 0.965) was recorded on the Virus Data Sheet.
The sample was immediately processed by the Organic Flocculation Concentration
Procedure. Following centrifugation at 4,000 *g, the supernatant was adjusted to pH 7.3 and
passed through a sterilizing filter. A Final Concentrated Sample Volume of 32.0 mL was
obtained, giving an Assay Sample Volume for Sampleville-02 of:
0 100 liters ~~ n , .,.. , ,
S = x 32.0 ml = 16.5 ml
194 liters
Subsample 1 was prepared by placing 0.55 x 16.5 mL = 9.1 mL into a separate
container. Subsample 2 was prepared by placing 0.67 x 16.5 mL =11.1 mL into a third
container. Subsample 2 and the remaining portions of the Final Concentrated Sample were
frozen at-70°C.
Subsample 1 was inoculated onto each often 25 cm2 flasks of BGM cells at passage
127 using an inoculation volume of 16.5 mL + 20 = 0.82 mL per flask. A negative control
was prepared by inoculating a flask with 0.82 mL of 0.15 M Na2HPO4 • 7H2O, pH 7.3. A
positive control was prepared by inoculating a flask with 0.82 mL of 0.15 M Na2HPO4 •
7H2O, pH 7.3 containing 241.0 PFU/mL (200.0 PFU/0.82 mL) of attenuated poliovirus type 3.
Following adsorption, 9.18 mL of maintenance medium was added and the cultures were
incubated at 36.5°C.
On June 13 nine flasks inoculated with subsample 1 and the positive control showed
signs of CPE. After thawing subsample 2, a 1:5 dilution was prepared by mixing 0.1334 x
16.5 = 2.20 mL of subsample 2 with 0.5334 x 16.5 = 8.80 mL of 0.15 MNa2HPO4 • 7H2O,
pH 7.3. A 1:25 dilution was prepared by mixing 2.20 mL of the 1:5 dilutions with 8.80 mL of
0.15 M Na2HPO4 • 7H2O, pH 7.3. Ten 25 cm2 flasks of BGM cells at passage 128 were then
inoculated with 0.82 mL each of undiluted subsample 2. Ten flasks were inoculated with
0.82 mL each of subsample 2 diluted 1:5 and ten flasks were inoculated with 0.82 mL each of
subsample 2 diluted 1:25. Another negative control and positive control were also prepared
and inoculated.
By June 20 all 10 flasks inoculated with subsample 1 showed signs of CPE and were
repassaged as described in example 1.
VIII-56
-------
By June 27 all 10 flasks inoculated with undiluted subsample 2 had developed CPE.
Eight flasks inoculated with the 1:5 dilution of subsample 2 and four flasks inoculated with
the 1:25 dilution of subsample 2 demonstrated CPE. All flasks were re-passaged as described
for example 1.
By July 5th all 10 flasks from the second passage of subsample 1 were confirmed as
positive and were discarded.
By July 11th all 10 flasks inoculated with the second passage of undiluted subsample 2
had developed CPE. The eight positive flasks from the 1st passage of the 1:5 dilution of
subsample 2 were positive in the second passage. Three flasks inoculated with the second
passage of the 1:25 dilution of subsample 2 remained positive.
The MPN software program supplied by the U.S. EPA was used to calculate the
MPN/mL and 95% confidence limit values. After the main screen appeared, "G. NUMBER
OF DILUTIONS" was changed from 1 to 3. "H. NUMBER OF REPLICATES PER DILU-
TION" was changed from 20 to 10 and "I. SIZE OF INOCULUM VOLUME (mL)" was
changed from 1 to 0.82. "A. PROCEED WITH DATA INPUT" was pressed followed by
"ENTER" to overwrite the existing output file. The number of positive replicates per dilution,
"10, 8, and 3" was entered with the values separated by spaces. Following program calcula-
tions, the MPN/mL and 95% Confidence Limit values/mL were recorded onto the
Quantitation of Total Culturable Virus Data Sheet. The program was exited by pressing
"I. EXIT THE PROGRAM."
The MPN per 100 liter value (M,) was calculated according to the formula:
100 MmS 100x10.15x16.5 .,„
M, = = = ID/
1 D 100
where Mm is the MPN value per milliliter from the Quantitation of Total Culturable Virus
Data Sheet, S is the Assay Sample Volume and D is the Volume of Original Water Sample
Assayed (S and D are obtained from the Virus Data Sheet).
The Lower 95% Confidence Limit per 100 liter (CL^ was calculated according to the
formula:
_ 100 CLlmS _ 100 x 5.04 x 16.5 _ „ 1
L-Li, — — — oJ.l
1 D 100
where CLlm is the lower 95% confidence limit per milliliter from the Quantitation of Total
Culturable Virus Data Sheet.
VIII-57
-------
The Upper 95% Confidence Limit per 100 liter (CLU) was calculated according to the
formula:
S 100 x 18.25 x 16.5
D 100
where CLum is the upper 95% confidence limit per milliliter from the Quantitation of Total
Culturable Virus Data Sheet
VIII-58
-------
SAMPLE DATA SHEET
SAMPLE NUMBER: Sampleville-02
UTILITY NAME: Sampleville Water Works
UTILITY ADDRESS: 1 Water Street
CITY: Sampleville STATE: OH ZIP: 45999
SAMPLER'S NAME: Mr. Brian Hall
WATER TEMPERATURE: 26.5 °C TURBIDITY: 2.3 NTU
WATER pH: 7.7
ADJUSTED WATER pH: NA
THIOSULFATE ADDED: (CHECK) _YES .XNO
INIT. METER READING: 6129.3 CHECK UNITS: .X gallons .ft3
date: 6/5/95 time: 8:30 am
FINAL METER READING: 6182.3 CHECK UNITS: .X gallons .ft3
date: 6/5/95 time: 9:00 am
TOTAL SAMPLE VOLUME: 200.63 L
(Final-Initial meter readings x 3.7854 (for readings in gallons)
or x 28.316 (for readings in ft3))
SHIPMENT DATE: 6/5/95
CONDITION ON ARRIVAL: Cold/Not frozen
COMMENTS:
VIII-59
-------
VIRUS DATA SHEET
SAMPLE NUMBER: SAMPLEVILLE-02
ANALYTICAL LABORATORY NAME: CEPOR LABORATORIES
ANALYTICAL LABORATORY ADDRESS: 42 RUECKERT ST.
CITY: CINCINNATI STATE: OH ZIP: 45219
ADJUSTED TOTAL SAMPLE VOLUME (ATSV):
. i
194 L
DATEELUTED: 6/6/95
TIME: 9:50 am
ELUATE VOLUME RECOVERED:
985 mL
VOLUME OF ELUATE ARCHIVED:
0 mL
DATE CONCENTRATED: 6/6/95
TIME: 1pm
FINAL CONCENTRATED SAMPLE VOLUME (FCSV):
32.0 mL
ASSAY SAMPLE VOLUME (S):
16.5 mL
VOLUME OF ORIGINAL WATER SAMPLE
ASSAYED (D):
100 L2
INOCULUM VOLUME:
0.82 mL
DATES ASSAYED BY
CPE:
1st Passage
2nd Passage
3rd Passage
(If necessary)
Subsample 1:
Subsample 2:
6/6/95
6/13/95
MPN/100 L3: 167
6/20/95
6/27/95
95% CONFIDENCE LIMITS
LOWER: 83 UPPER: 301
COMMENTS:
ANALYST: E.G. Moore
JEnter the Total Sample Volume times 0.965 if a coliphage sample is taken, times 0.9 if
archiving is required, times 0.865 if a coliphage sample is taken and archiving is
required or times 1 if a coliphage sample is not taken and archiving is not required.
2Must be at least 100 L for source water and 1000 L for finished water.
3Value calculated from the Quantitation of Total Culturable Virus form as described in
the Virus Quantitation section of Part 3.
VIII-60
-------
TOTAL CULTURABLE VIRUS DATA SHEET
SAMPLE #: Sampleville-02
Sample
1st Passage
Neg. Cont.
Pos. Cont.
Undiluted
1:5 Dil.
1:25 Dil.
2nd Passage1
Neg. Cont.
Pos. Cont.
Undiluted
1:5 Dil.
1:25 Dil.
3rd Passage2
Neg. Cont.
Pos. Cont.
Undiluted
1:5 Dil.
1:25 Dil.
Total Number of Replicates
Subsample 1
Inoculated
1
1
10
1
1
10
Without
CPE
1
0
0
1
0
0
With CPE
0
1
10
0
1
10
Subsample 2
Inoculated
1
1
10
10
10
1
1
10
10
10
Without
CPE
1
0
0
2
6
1
0
0
2
7
With CPE
0
1
10
8
4
0
1
10
8
3
*A portion of medium from each 1st passage vessel, including controls, must be repas-
saged for conformation. The terms "Undiluted," "1:5 Dilution" and "1:25 Dilution"
under the 2nd and 3rd Passage headings refer to the original sample dilutions for the
1st passage. If higher dilutions are used, record the data from the three highest
dilutions showing positive results and place the actual dilution amount in the sample
column.
2Samples that were negative on the first passage and positive on the 2nd passage must
be passaged a third time for conformation. If a third passage is required, all controls
must be passaged again.
VIII-61
-------
QUANTITATION OF TOTAL CULTURABLE VIRUS DATA SHEET
SAMPLE NUMBER: Sampleville-02
Sample
Number
Replicates
inoculated
Number
with CPE
Undiluted Samples
Subsample 1
Subsample 2
Total Undiluted
10
NA
10
NA
Subsample 2 results (Dilutions Required)
Undiluted
1:5 Dilution
1:25 Dilution
10
10
10
10
8
3
MPN/mL1
10.15
95% Confidence
Limits
Lower
5.04
Upper
18.25
*Use the values recorded in the Total Undiluted row to calculate the MPN/mL result
and confidence limits when dilutions are not required. If dilutions are required, base
the calculation upon the values recorded in the Undiluted, 1:5 Diluted and 1:25 Diluted
rows for subsample 2. If higher dilutions are used for subsample 2, record the data
from the three highest dilutions showing positive results and place the actual dilution
amount in the sample column. The MPN/mL and 95% Confidence Limit values must
be obtained using the computer program supplied by the U.S. EPA.
VIII-62
-------
PART 9 — DATA SHEETS
7Copies of all Data Sheets are available upon request in WordPerfect for Windows,
version 6.1 format. Send requests to the ICR Laboratory Coordinator, USEPA, TSD, 26
W. Martin Luther King Drive, Cincinnati, OH 45268.
VIII-63
-------
SAMPLE DATA SHEET
SAMPLE NUMBER:
UTILITY NAME:
UTILITY ADDRESS:
CITY:
STATE:
ZIP:
SAMPLER'S NAME:
WATER TEMPERATURE:
TURBIDITY:
NTU
WATER pH:
ADJUSTED WATER pH:
THIOSULFATE ADDED:
(CHECK) _YES _NO
INIT. METER READING:
date:
CHECK UNITS:
time:
gallons ft3
FINAL METER READING:
date:
CHECK UNITS:
time:
gallons ft3
TOTAL SAMPLE VOLUME: L
(Final-Initial meter readings x 3.7854 (for readings in gallons)
or x 28.316 (for readings in ft3))
SHIPMENT DATE:
CONDITION ON ARRIVAL:
COMMENTS:
VIII-64
-------
VIRUS DATA SHEET
SAMPLE NUMBER:
ANALYTICAL LABORATORY NAME:
ANALYTICAL LABORATORY ADDRESS:
CITY: STATE:
ZIP:
ADJUSTED TOTAL SAMPLE VOLUME (ATSV):
. i
DATE ELUTED:
TIME:
ELUATE VOLUME RECOVERED:
mL
VOLUME OF ELUATE ARCHIVED:
mL
DATE CONCENTRATED:
TIME:
FINAL CONCENTRATED SAMPLE VOLUME (FCSV):
mL
ASSAY SAMPLE VOLUME (S):
mL
VOLUME OF ORIGINAL WATER SAMPLE
ASSAYED (D):
INOCULUM VOLUME:
mL
DATES ASSAYED
BY CPE:
1st Passage
2nd Passage
3rd Passage
(If necessary)
Subsample 1:
Subsample 2:
MPN/100 L3:
95% CONFIDENCE LIMITS
LOWER: UPPER:
COMMENTS:
ANALYST:
JEnter the Total Sample Volume times 0.965 if a coliphage sample is taken, times 0.9 if
archiving is required, times 0.865 if a coliphage sample is taken and archiving is
required or times 1 if a coliphage sample is not taken and archiving is not required.
2Must be at least 100 L for source water and 1000 L for finished water.
3Value calculated from the Quantitation of Total Culturable Virus form as described in
the Virus Quantitation section of Part 3.
VIII-65
-------
TOTAL CULTURABLE VIRUS DATA SHEET
SAMPLE #:
Sample
1st Passage
Neg. Cont.
Pos. Cont.
Undiluted
1:5 Dil.
1:25 Dil.
2nd Passage1
Neg. Cont.
Pos. Cont.
Undiluted
1:5 Dil.
1:25 Dil.
3rd Passage2
Neg. Cont.
Pos. Cont.
Undiluted
1:5 Dil.
1:25 Dil.
Total Number of Replicates
Subsample 1
Inoculated
Without
CPE
With CPE
Subsample 2
Inoculated
Without
CPE
With CPE
*A portion of medium from each 1st passage vessel, including controls, must be re-
passaged for conformation. The terms "Undiluted," "1:5 Dilution" and "1:25
Dilution" under the 2nd and 3rd Passage headings refer to the original sample
dilutions for the 1st passage. If higher dilutions are used, record the data from the
three highest dilutions showing positive results and place the actual dilution amount in
the sample column.
2Samples that were negative on the first passage and positive on the 2nd passage must
be passaged a third time for conformation. If a third passage is required, all controls
must be passaged again.
VIII-66
-------
QUANTITATION OF TOTAL CULTURABLE VIRUS DATA SHEET
SAMPLE NUMBER:
Sample
Number
Replicates
inoculated
Number
with CPE
Undiluted Samples
Subsample 1
Subsample 2
Total Undiluted
Subsample 2 results (Dilutions Required)
Undiluted
1:5 Dilution
1:25 Dilution
MPN/mL1
95% Confidence
Limits
Lower
Upper
*Use the values recorded in the Total Undiluted row to calculate the MPN/mL result
and confidence limits when dilutions are not required. If dilutions are required, base
the calculation upon the values recorded in the Undiluted, 1:5 Diluted and 1:25 Diluted
rows for subsample 2. If higher dilutions are used for subsample 2, record the data
from the three highest dilutions showing positive results and place the actual dilution
amount in the sample column. The MPN/mL and 95% Confidence Limit values must
be obtained using the computer program supplied by the U.S. EPA.
VIII-67
-------
SECTION IX. COLIPHAGE ASSAY
This Section outlines the procedures for coliphage detection by plaque assay. It should
be noted that the samples to be analyzed may contain pathogenic human enteric viruses.
Laboratories performing the coliphage analysis are responsible for establishing an adequate
safety plan.
ASSAY COMPONENTS
Apparatus and Materials:
1. Sterilizing filter — 0.45 jim (Nuclepore Product No. 140667 or equivalent).
Always pass about 10 mL of 1.5% beef extract through the filter just prior to use to
minimize phage adsorption to the filter.
2. Water bath set at 44.5 ± 1 °C.
3. Incubator set at 36.5 ± 1 °C.
Media and Reagents:
The amount of media prepared may be increased proportionally to the number of
samples to be analyzed.
1. Saline-calcium solution — dissolve 8.5 g of NaCl and 0.22 g of CaCl2 in a total of 1 L of
dH2O. Dispense in 9 mL aliquots in 16 x 150 mm screw-capped test tubes (Baxter Product
No. T1356-6A or equivalent) and sterilize by autoclaving at 121 °C for 15 min.
2. Tryptone agar slants — add 1.0 g tryptone (Difco Product No. 0123 or equivalent), 0.1 g
yeast extract (Difco Product No. 0127 or equivalent), 0.1 g glucose, 0.8 g NaCl, 0.022 g CaCl2,
and 1.2 g of Bacto-agar (Difco Product No. 0140 or equivalent) to a total volume of 100 mL of
dH2O in a 250 mL flask. Dissolve by autoclaving at 121 °C for 20 min and dispense 8 mL
aliquots into 16 x 150 mm test tubes with tube closures (Baxter Product Nos. T1311-16XX
and T1291-16 or equivalent). Prepare slants by allowing the agar to solidify with the tubes at
about a 20° angle. Slants may be stored at 4°C for up to two months.
3. Tryptone bottom agar — Prepare one day prior to sample analysis using the ingredients
and concentrations listed for tryptone agar slants, except use 1.5 g of Bacto-agar. After
autoclaving, pipet 15 mL aliquots aseptically into sterile 100 x 15 mm petri plates and allow
the agar to harden. Store the plates at 4°C overnight and warm to room temperature for 1 h
before use.
IX-1
-------
4. Tryptone top agar — Prepare the day of sample analysis using the ingredients and
concentrations listed for tryptone agar slants, except use 0.7 g of Bacto-agar. Autoclave and
place in the 44.5 ± 1 °C water bath.
5. Tryptone broth — Prepare on the day prior to sample analysis as for tryptone agar slants,
except without agar.
6. Beef extract V powder (BBL Microbiology Systems Product No. 97531) — prepare
buffered 1.5% beef extract by dissolving 1.5 g of beef extract powder and 0.375 g of glycine
(final glycine concentration = 0.05 M) in 90 mL of dH2O. Adjust the pH to 7.0 - 7.5, if
necessary, and bring the final volume to 100 mL with dH2O. Autoclave at 121 °C for 15 min
and use at room temperature.
Beef extract solutions may be stored for one week at 4 °C or for longer periods at -20 °C.
SAMPLE PROCESSING
Step 1. To measure the concentration of coliphage in water samples, use the coliphage sample
prepared from the pH-adjusted 1MDS eluate as described in the Elution Procedure in Part 2
of Section VII. Virus Monitoring Protocol.
Step 2. Filter the coliphage sample through a 0.45 jim sterilizing filter.
Step 3. Assay ten 1 mL volumes each for somatic and male-specific coliphage within 24 h.
Store the remaining eluate at 4°C to serve as a reserve in the event of sample contamination or
high coliphage densities. If the coliphage density is expected or demonstrated to be greater
than 100 PFU/mL, dilute the original or remaining eluate with a serial 1:10 dilution series into
saline-calcium solutions. Assay the dilutions which will result in plaque counts of 100 or less.
SOMATIC COLIPHAGE ASSAY
Storage of E. coli C Host Culture for Somatic Coliphage Assay:
1. For short term storage inoculate a Escherichia coli C (American Type Culture Collection
Product No. 13706) host culture onto tryptone agar slants with a sterile inoculating loop by
spreading the inoculum evenly over entire slant surface. Incubate the culture overnight at 36.5
± 1 °C. Store at 4°C for up to two weeks.
2. For long term storage inoculate a 5-10 mL tube of tryptone broth with the host culture.
Incubate the broth culture overnight at 36.5 ± 1 °C. Add l/10th volume of sterile glycerol.
Dispense into 1 mL aliquots in cryovials (Baxter Product No. T4050-8 or equivalent) and store
at-70°C.
IX-2
-------
Preparation of Host for Somatic Coliphage Assay:
Step 1. Inoculate 5 mL of tryptone broth with E. coli C from a slant with an inoculating loop
and incubate for 16 h at 36.5 ± 1 °C.
Step 2. Transfer 1.5 mL of the 16 h culture to 30 mL of tryptone broth in a 125 mL flask and
incubate for 4 h at 36.5 ± 1 °C with gentle shaking. The amount of inoculum and broth used in
this step can be proportionally altered according to need.
Preparation of <|)X174 Positive Control:
Step 1. Rehydrate a stock culture of (|)X174 (American Type Culture Collection Product No.
13706-B1) and store at 4°C.
Step 2. Prepare a 30 mL culture of E. coli C as described in section titled Preparation of Host
for Somatic Coliphage Assay. Incubate for 2 h at 36.5 ± 1 °C with shaking. Add 1 mL of
rehydrated phage stock and incubate for an additional 4 h at 36.5 ± 1 °C.
Step 3. Filter the culture through a 0.45 jim sterilizing filter.
Step 4. Prepare 10"7, 10"8 and 10"9 dilutions of the filtrate using saline-calcium solution tubes.
These dilutions should be sufficient for most <$X174 stocks. Some stocks may require
higher or lower dilutions.
Step 5. Add 1 mL of the 10"9 dilution into each of five 16 x 150 mm test tubes. Using the
same pipette, add 1 mL of the 10"8 dilution into each of five additional tubes and then 1 mL of
the 10"7 dilution into five tubes. Label the tubes with the appropriate dilution.
Step 6. Add 0.1 mL of the host culture into each of the 15 test tubes from Step 5.
Step 7. Add 3 mL of the melted tryptone top agar held in the 44.5 ± 1 °C water bath to one
test tube at a time. Mix and immediately pour the contents of the tube over the bottom agar of
a petri dish labeled with sample identification information. Rotate the dish to spread the
suspension evenly over the surface of the bottom agar and place it onto a level surface to allow
the agar to solidify.
Step 8. Incubate the inoculated plates at 36.5 ± 1 °C overnight and examine for plaques the
following day.
Step 9. Count the number of plaques on each of the 15 plates (don't count plates giving
plaque counts significantly more than 100). The five plates from one of the dilutions should
IX-3
-------
give plaque counts of about 20 to 100 plaques. Average the plaque counts on these five plates
and multiply the result by the reciprocal of the dilution to obtain the titer of the undiluted stock.
Step 10. Dilute the filtrate to 30 to 80 PFU/mL in tryptone broth for use in a positive control
in the coliphage assay. Store the original filtrate and the diluted positive control at 4°C.
Before using the positive control for the 1st time, place 1 mL each into ten 16 x 750 mm
test tubes and assay using Steps 6-8. Count the plaques on all plates and divide by 10. If the
result is not 30 to 80, adjust the dilution of the positive control sample and assay again.
Procedure for Somatic Coliphage Assay:
Step 1. Sample preparation:
a. Add 1 mL of the water eluate sample to be tested to each of ten 16 x 150 mm test
tubes.
b. Add 1 mL of buffered 1.5% beef extract to a 16 x 150 mm test tube for a negative
control.
c. Add 1 mL of the diluted (|)X174 positive control to another 16 x 150 mm test tube.
Step 2. Add 0.1 mL of the host culture to each test tube containing eluate or positive control.
Step 3. Add 3 mL of the melted tryptone top agar held in the 44.5 ± 1 °C water bath to one test
tube at a time. Mix and immediately pour the contents of the tube over the bottom agar of a
petri dish labeled with sample identification information. Tilt and rotate the dish to spread the
suspension evenly over the surface of the bottom agar and place it onto a level surface to allow
the agar to solidify.
Step 4. Incubate the inoculated plates at 36.5 ± 1 °C overnight and examine for plaques the
following day.
Step 5. Count the total number of plaques on the ten plates receiving the water eluate.
Step 6. Somatic coliphage enumeration.
IX-4
-------
a. Calculate the somatic coliphage titer (Vs) in PFU per 100 L according to the formula:
T, 100 x p x D x E
V^ =
S I x C
where P is the total number of plaques from Step 5, D is the reciprocal of the dilution
made on the inoculum before plating (D = 1 for undiluted samples) and E is the total vol-
ume of eluate recovered (from the Virus Data Sheet of the Total Culturable Virus Proto-
col). I is the total volume (in mL) of the eluate sample assayed on the ten plates. C is the
amount of water sample filtered in liters (from the Sample Data Sheet of the Total Cultur-
able Virus Protocol). Record the value of Vs in the ICR database.
b. Count the plaques on the positive control plate. Maintain a record of the plaque
count as a check on the virus sensitivity of the E. coli C host. Assay any water eluate
samples again where the positive control counts are more than one log below their normal
average.
MALE-SPECIFIC COLIPHAGE ASSAY
Storage of E. coli Famp Host Culture for Male-Specific Coliphage Assay:J
1. For short term storage inoculate a Escherichia coli Famp host culture onto tryptone agar
slants with a sterile inoculating loop by spreading the inoculum evenly over entire slant
surface. Incubate the culture overnight at36.5± 1 °C. Store at 4°C for up to two weeks.
2. For long term storage inoculate a 5-10 mL tube of tryptone broth with the host culture.
Incubate the broth culture overnight at 36.5 ± 1 °C. Add l/10th volume of sterile glycerol.
Dispense into 1 mL aliquots in cryovials (Baxter Product No. T4050-8 or equivalent) and store
at-70°C.
Preparation of Host for Male-Specific Coliphage Assay:
Step 1. Inoculate 5 mL of tryptone broth with E. coli Famp from a slant with an inoculating
loop and incubate for 16 h at 36.5 ± 1 °C.
JThe term "male-specific coliphage" refers to coliphages whose receptor sites are
located on the bacterial F-pilus. The E. coli Famp strain to be used for ICR monitoring
will be provided to virus analytical laboratories by a U.S. EPA contractor.
IX-5
-------
Step 2. Transfer 1.5 mL of the 16 h culture to 30 mL of tryptone broth in a 125 mL flask and
incubate for 4 h at 36.5 ± 1 °C with gentle shaking. The amount of inoculum and broth used in
this step can be proportionally altered according to need.
Preparation of MS22 Positive Control:
Step 1. Rehydrate a stock culture of MS2 (American Type Culture Collection Product No.
15597-B1) and store at 4°C.
Step 2. Prepare a 30 mL culture of E. coli Famp as described in section titled Preparation of
Host for Male-Specific Coliphage Assay. Incubate for 2 h at 36.5 ± 1 °C with shaking. Add 1
mL of rehydrated phage stock and incubate for an additional 4 h at 36.5 ± 1 °C.
Step 3. Filter the culture through a 0.45 jim sterilizing filter.
Step 4. Prepare 10"7, 10"8 and 10"9 dilutions of the filtrate using saline-calcium solution tubes.
These dilutions should be sufficient for mostMS2 stocks. Some stocks may require higher
or lower dilutions.
Step 5. Add 1 mL of the 10"9 dilution into each of five 16 x 150 mm test tubes. Using the
same pipette, add 1 mL of the 10"8 dilution into each of five additional tubes and then 1 mL of
the 10"7 dilution into five tubes. Label the tubes with the appropriate dilution.
Step 6. Add 0.1 mL of the host culture into each of the 15 test tubes from Step 5.
Step 7. Add 3 mL of the melted tryptone top agar held in the 44.5 ± 1 °C water bath to one test
tube at a time. Mix and immediately pour the contents of the tube over the bottom agar of a
petri dish labeled with sample identification information. Rotate the dish to spread the
suspension evenly over the surface of the bottom agar and place it onto a level surface to allow
the agar to solidify.
Step 8. Incubate the inoculated plates at 36.5 ± 1 °C overnight and examine for plaques the
following day.
Step 9. Count the number of plaques on each of the 15 plates (don't count plates giving plaque
counts significantly more than 100). The five plates from one of the dilutions should give
plaque counts of about 20 to 100 plaques. Average the plaque counts on these five plates and
multiply the result by the reciprocal of the dilution to obtain the titer of the undiluted stock.
2The MS2 positive control strain or a mixture of male-specific coliphage strains to be
used for positive or quality controls will be supplied to virus analytical laboratories by a
U.S. EPA contractor.
IX-6
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Step 10. Dilute the filtrate to 30 to 80 PFU/mL in tryptone broth for use in a positive control
in the coliphage assay. Store the original filtrate and the diluted positive control at 4°C.
Before using the positive control for the 1st time, place 1 mL each into ten 16 x 750 mm
test tubes and assay using Steps 6-8. Count the plaques on all plates and divide by 10. If the
result is not 30 to 80, adjust the dilution of the positive control sample and assay again.
Procedure for Male-Specific Coliphage Assay:
Step 1. Sample preparation:
a. Add 1 mL of the water eluate sample to be tested to each of ten 16 x 150 mm test
tubes.
b. Add 1 mLofbuffered 1.5% beef extract to a 16 x 150 mm test tube for a negative
control.
c. Add 1 mL of the diluted MS2 positive control to another 16 x 150 mm test tube.
Step 2. Add 0.1 mL of the host culture to each test tube containing eluate or positive control.
Step 3. Add 3 mL of the melted tryptone top agar held in the 44.5 ± 1 °C water bath to one test
tube at a time. Mix and immediately pour the contents of the tube over the bottom agar of a
petri dish labeled with sample identification information. Tilt and rotate the dish to spread the
suspension evenly over the surface of the bottom agar and place it onto a level surface to allow
the agar to solidify.
Step 4. Incubate the inoculated plates at 36.5 ± 1 °C overnight and examine for plaques the
following day.
Step 5. Count the total number of plaques on the ten plates receiving the water eluate.
Step 6. Male Specific coliphage enumeration.
IX-7
-------
a. Calculate the male specific coliphage titer (VM) in PFU per 100 L according to the
formula:
, 100 x p x D x E
where P is the total number of plaques from Step 5, D is the reciprocal of the dilution
made on the inoculum before plating (D = 1 for undiluted samples) and E is the total vol-
ume of eluate recovered (from the Virus Data Sheet of the Total Culturable Virus Proto-
col). I is the total volume (in mL) of the eluate sample assayed on the ten plates. C is the
amount of water sample filtered in liters (from the Sample Data Sheet of the Total Cul-
turable Virus Protocol). Record the value of VM in the ICR database.
b. Count the plaques on the positive control plate. Maintain a record of the plaque
count as a check on the virus sensitivity of the bacterial host. Assay any water eluate
samples again where the positive control counts are more than one log below their normal
average.
IX-8
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SECTION X. MEMBRANE FILTER METHOD FOR E. coli
1. Citation: METHOD 1103.1, 1985
2. Scope
2.1 This method describes a membrane filter (MF) procedure for the detection and
enumeration of Escherichia coli (E. coif). Because the bacterium is a natural
inhabitant only of the intestinal tract of warm-blooded animals, its presence in
water samples is an indication of fecal pollution and the possible presence of
enteric pathogens.
2.2 The E. coli test is used as a measure of recreational water quality. Epidemiological
studies have led to the development of criteria which can be used to promulgate
recreational water standards based on established relationships between health
effects and water quality. The significance of finding E. coli in recreational water
samples is the direct relationship between the density of E. coli and the risk of
gastrointestinal illness associated with swimming in the water (1).
2.3 The test for E. coli can be applied to fresh, estuarine and marine waters.
2.4 Since a wide range of sample volumes or dilutions thereof can be analyzed by the
MF technique, a wide range of E. coli levels in water can be detected and enumer-
ated.
3. Summary - The MF method provides a direct count of bacteria in water based on the
development of colonies on the surface of the membrane filter (2). A water sample is
filtered through the membrane which retains the bacteria. After filtration, the membrane
containing the bacterial cells is placed on a selective and differential medium, M-TEC,
incubated at 35 °C for 2 h to resuscitate injured or stressed bacteria, and then incubated at
44.5 °C for 22 h. Following incubation, the filter is transferred to a filter pad saturated
with urea substrate. After 15 min, yellow or yellow-brown colonies are counted with the
aid of a fluorescent lamp and a magnifying lens.
4. Definition - In this method, E. coli are those bacteria which produce yellow or yellow-
brown colonies on a filter pad saturated with urea substrate broth after primary culturing
on M-TEC medium.
5. Interferences - Water samples containing colloidal or suspended paniculate material can
clog the membrane filter and prevent filtration, or cause spreading of bacterial colonies
which could interfere with identification of target colonies.
X-l
-------
6. Safety Precautions
6.1 The analyst/technician must know and observe the normal safety procedures
required in a microbiology laboratory while preparing, using, and disposing of
cultures, reagents and materials and while operating sterilization equipment.
6.2 Mouth-pipetting is prohibited.
7. Apparatus and Equipment
7.1 Glass lens, 2-5X magnification, or stereoscopic microscope.
7.2 Lamp with cool, white fluorescent tube and diffuser.
7.3 Hand tally or electronic counting device.
7.4 Pipet container, stainless steel, aluminum, or borosilicate glass, for glass pipets.
7.5 Pipets, sterile, T.D. bacteriological or Mohr, glass or plastic, of appropriate volume.
7.6 Graduated cylinders, covered with aluminum foil or kraft paper and sterile.
7.7 Membrane filtration units (filter base and funnel), glass, plastic or stainless steel,
wrapped with aluminum foil or kraft paper and sterile.
7.8 Ultraviolet unit for sterilizing the filter funnel between filtrations (optional).
7.9 Line vacuum, electric vacuum pump, or aspirator for use as a vacuum source. In
an emergency, or in the field, a hand pump, or a syringe equipped with a check
valve to prevent the return flow of air, can be used.
7.10 Flask, filter vacuum, usually 1 L, with appropriate tubing. A filter manifold to hold
a number of filter bases is optional.
7.11 Flask for safety trap, placed between the filter flask and the vacuum source.
7.12 Forceps, straight or curved, with smooth tips to handle filters without damage.
7.13 Ethanol, methanol or isopropanol in a small, wide-mouth container, for flame-
sterilizing forceps.
7.14 Burner, Bunsen or Fisher type, or electric incinerator unit for sterilizing inoculation
loops.
X-2
-------
7.15 Thermometer, checked against a National Institute of Science & Technology
(NIST) certified thermometer, or one traceable to an NIST thermometer.
7.16 Petri dishes, sterile, plastic, 50 x 12 mm, with tight-fitting lids, or 60 x 15 mm,
glass or plastic, with loose-fitting lids. 100 x 15 mm dishes may also be used.
7.17 Bottles, milk dilution, borosilicate glass, screw-cap with neoprene liners, marked at
99 mL for 1-100 dilutions. Dilution bottles marked at 90 mL, or tubes marked at 9
mL may be used for 1-10 dilutions.
7.18 Flasks, borosilicate glass, screw-cap, 250-2000 mL volume.
7.19 Membrane filters, sterile, white grid marked, 47 mm diameter, with 0.45 ± 0.02 jim
pore size.
7.20 Absorbent pads, sterile, 47 mm diameter (usually supplied with membrane filters).
7.21 Inoculation loops, at least 3 mm diameter, and needles, nichrome and platinum
wire, 26 B & S gauge, in suitable holders. Disposable applicator sticks or plastic
loops are alternatives to inoculation loops. Note: A platinum loop is required for
the cytochrome oxidase test in 15.3.
7.22 Incubator maintained at 35 ± 0.5 °C, with approximately 90 percent humidity if
loose-lidded petri dishes are used.
7.23 Waterbath incubator maintained at 44.5 ± 0.2°C.
7.24 Waterbath maintained at 44-46°C for tempering agar.
7.25 Test tubes, 150 x 20 mm, borosilicate glass or plastic.
7.26 Test tubes, 75 x 10 mm, borosilicate glass.
7.27 Test tube caps, aluminum or autoclavable plastic, for 20 mm diameter test tubes.
7.28 Test tubes, screw-cap, 125 x 16 mm or other appropriate size.
7.29 Filter paper.
X-3
-------
8. Reagents and Materials
8.1 Purity of Reagents: Reagent grade chemicals shall be used in all tests. Unless
otherwise indicated, reagents shall conform to the specifications of the Committee
on Analytical Reagents of the American Chemical Society (3). The agar used in
preparation of culture media must be of microbiological grade.
8.2 Whenever possible, use commercial culture media as a means of quality control.
8.3 Purity of Water: Reagent water conforming to Specification Dl 193, Type II water,
ASTM Annual Book of Standards (4)
8.4 Buffered Dilution Water
8.4.1 Composition:
Sodium Dihydrogen Phosphate 0.58 g
Sodium Monohydrogen Phosphate 2.50 g
Sodium Chloride 8.50 g
8.4.2 Preparation: Dissolve the ingredients in 1 L of reagent water in a flask
and dispense in appropriate amounts for dilutions in screw-cap bottles or
culture tubes, and/or into containers for use as rinse water. Autoclave after
preparation at 121 °C (15 Ib pressure) for 15 min. Final pH should be 7.4 ±
0.2.
8.5 M-TEC Agar (Difco 0334-15-0)
8.5.1 Composition:
Proteose Peptone #3 5.0 g
Yeast Extract 3.0 g
Lactose 10.0 g
NaCl 7.5 g
Dipotassium Phosphate 3.3 g
Monopotassium Phosphate 1.0 g
Sodium Lauryl Sulfate 0.2 g
Sodium Desoxycholate 0.1 g
Brom Cresol Purple 0.08 g
Brom Phenol Red 0.08 g
Agar 15.0 g
8.5.2 Preparation: Add 45.26 g of M-TEC medium to 1 L of reagent water in a
flask and heat to boiling, until ingredients dissolve. Autoclave at 121 °C
(15 Ib pressure) for 15 min. and cool in a 44-46°C waterbath. Pour the
X-4
-------
medium into each 50 x 10 mm culture dish to a 4-5 mm depth (approxi-
mately 4-6 mL) and allow to solidify. Final pH should be 7.3 ± 0.2. Store
in a refrigerator.
8.6 Urea Substrate Medium
8.6.1 Composition:
Urea 2.0 g
Phenol red 0.01 g
8.6.2 Preparation: Add dry ingredients to 100 mL reagent water in a flask. Stir
to dissolve and adjust to pH 5.0 with a few drops of IN HC1. The substrate
solution should be a straw-yellow color at this pH.
8.7 Nutrient Agar (Difco 0001 -02, BBL 11471)
8.7.1 Composition:
Peptone 5.0 g
Beef Extract 3.0 g
Agar 15.0 g
8.7.2 Preparation: Add 23 g of nutrient agar ingredients to 1 L of reagent water
and mix well. Heat in boiling waterbath to dissolve the agar completely.
Dispense in screw-cap tubes, bottles or flasks and autoclave at 121 °C (15 Ib
pressure) for 15 min. Remove tubes and slant. The final pH should be 6.8
±0.2.
8.8 Tryptic Soy Broth (Difco 0370-02) or Trypticase Soy Broth (BBL 12464)
8.8.1 Composition:
Tryptone or Trypticase 17.0 g
Soytone or Phytone 3.0 g
Sodium Chloride 5.0 g
Dextrose 2.5 g
Dipotassium Phosphate 2.5 g
8.8.2 Preparation: Add 30 g of Tryptic (Trypticase) soy broth to 1 L of reagent
water. Warm the broth and mix gently to dissolve the medium completely.
Dispense in screw-cap tubes and autoclave at 121 °C (15 Ib pressure) for 15
min. The final pH should be 7.3 ± 0.2.
X-5
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8.9 Simmons' Citrate Agar (BBL 11619, Difco 0091-02)
8.9.1 Composition
Magnesium Sulfate 0.2 g
Monoammonium Phosphate 1.0 g
Dipotassium Phosphate 1.0 g
Sodium Citrate 2.0 g
Sodium Chloride 5.0 g
Brom Thymol Blue 0.08 g
Agar 15.0 g
8.9.2 Preparation: Add 24.28 g of Simmons' citrate agar to 1 L of reagent
water. Heat in boiling waterbath with mixing for complete solution.
Dispense in screw-cap tubes and sterilize at 121 °C (15 Ib pressure) for 15
min. Cool tubes as slants. The final pH should be 6.8 ± 0.2.
8.10 Tryptone (Difco 0123-02) or Trypticase Peptone (BBL 11920) Broth
8.10.1 Composition:
Tryptone or Trypticase peptone 10.0 g
8.10.2 Preparation: Add 10 g of tryptone or trypticase peptone to 900 mL of
reagent water and heat with mixing until dissolved. Bring solution to 1000
mL in a graduate or flask. Dispense in five mL volumes in tubes and
autoclave at 121 °C (15 Ib pressure) for 15 min. The final pH should be 7.2
±0.2.
8.11 EC Broth (Difco 0314-02) or EC Broth (BBL 12432)
8.11.1 Composition:
Tryptose or Trypticase Peptone 20.0 g
Lactose 5.0 g
Bile Salts No. 3 or
Bile Salts Mixture 1.5 g
Dipotassium Phosphate 4.0 g
Monopotassium Phosphate 1.5 g
Sodium Chloride 5.0 g
8.11.2 Preparation: Add 37 g of EC medium to 1 L of reagent water and warm
to dissolve completely. Dispense into fermentation tubes (150 x 20 mm
tubes containing inverted 75 x 10 mm vials). Sterilize at 121 °C (15 Ib
pressure) for 15 min. The final pH should be 6.9 ± 0.2.
X-6
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8.12 Cytochrome Oxidase Reagent: N, N, N1, N1 tetramethyl-p-phenylenediamine
dihydrochloride, 1% aqueous solution.
8.13 Kovacs' Indole Reagent: Dissolve 10 g p-dimethylaminobenzaldehyde in 150
mL amyl or isoamyl alcohol and then slowly add 50 mL concentrated hydro-
chloric acid and mix.
9. Sample Collection. Preservation and Holding Times
9.1 Sampling procedures are described in detail in the USEPA Microbiology Methods
Manual, Section II, A (5). Adherence to sample preservation procedures and
holding time limits is critical to the production of valid data. Samples not collected
according to these rules should not be analyzed.
9.1.1 Storage Temperature and Handling Conditions: Ice or refrigerate water
samples at a temperature of 1-4°C during transit to the laboratory. Use
insulated containers to assure proper maintenance of storage temperature.
Take care that sample bottles are not totally immersed in water during
transit or storage.
9.1.2 Holding Time Limitations: Examine samples as soon as possible after
collection. Do not hold samples longer than 8 h between collection and
initiation of analyses.
10. Calibration and Standardization
10.1 Check temperatures in incubators daily to insure operation within stated limits.
10.2 Check thermometers at least annually against an NIST certified thermometer or
one traceable to NIST. Check mercury columns for breaks.
11. Quality Control
11.1 See recommendations on quality control for microbiological analyses in the
USEPA Microbiology Methods Manual, Part IV, C (5)
12. Procedures
12.1 Prepare the M-TEC agar and urea substrate as directed in Sections 8.5 and 8.6.
12.2 Mark the petri dishes and report forms with sample identification and sample
volumes.
X-7
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12.3 Place a sterile membrane filter on the filter base, grid-side up and attach the
funnel to the base; the membrane filter is now held between the funnel and the
base.
12.4 Shake the sample bottle vigorously about 25 times to distribute the bacteria
uniformly and measure the desired volume of sample or dilution into the funnel.
12.5 For ambient surface waters and waste waters, select sample volumes based on
previous knowledge of pollution level, to produce 20-80 E. coli colonies on the
membranes. Sample volumes of 1-100 mL are normally tested at half-log
intervals.
12.6 Smaller sample size or sample dilutions can be used to minimize the interference
of turbidity or high bacterial densities. Multiple volumes of the same sample
dilution may be filtered and the results combined.
12.7 Filter the sample and rinse the sides of the funnel at least twice with 20-30 mL
of sterile rinse water. Turn off the vacuum and remove the funnel from the filter
base.
12.8 Use sterile forceps to aseptically remove the membrane filter from the filter base
and roll it onto the M-TEC agar to avoid the formation of bubbles between the
membrane and the agar surface. Reseat the membrane, if bubbles occur. Close
the dish, invert, and incubate at 35 °C for 2 h.
12.9 After 2 h incubation at 35 °C, transfer the plates to Whirl-Pak bags, seal, and
place inverted in a 44.5 °C waterbath for 22-24 h.
12.10 After 22-24 h, remove the dishes from the waterbath. Place absorbent pads in
new petri dishes or the lids of the same petri dishes, and saturate with urea broth.
Aseptically transfer the membranes to absorbent pads saturated with urea
substrate and hold at room temperature.
12.11 After 15-20 min. incubation on the urea substrate at room temperature, count
and record the number of yellow or yellow-brown colonies on those membrane
filters ideally containing 20-80 colonies.
X-8
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13. Calculation of Results
13.1 Select the membrane filter with the number of colonies within the acceptable
range (20-80) and calculate the count per 100 mL according to the general
formula:
„ 7 . No. E. coli Colonies Counted , „„ T
E. colil100 mL = x 100 mL
Volume in mL of Sample Filtered
13.2 See general counting rules in the USEPA Microbiology Methods Manual,
Part II, C, 3.5(5).
14. Reporting Results
14.1 Report the results as E. coli per 100 mL of sample.
15. Verification Procedure
15.1 Yellow or yellow-brown colonies from the urease test can be verified as E. coli.
Verification of colonies may be required in evidence gathering, and is also
recommended as a QC procedure with initial use of the test and with changes in
sample sites, lots of commercial media or major ingredients in media com-
pounded in the laboratory. The verification procedure follows:
15.1.1 Using a sterile inoculation loop, transfer growth from the centers of at least
10 well-isolated typical colonies to nutrient agar plates or slants and to
Tryptic (Trypticase) soy broth. Incubate the agar and broth cultures for 24
hat35°C.
15.1.2 After incubation remove a generous portion of material from the nutrient
agar with a platinum loop and deposit on the surface of filter paper that
has been saturated with cytochrome oxidase reagent prepared fresh that
day. A positive test is indicated within 15 s by the development of a deep
purple color where the bacteria were deposited.
15.1.3 Transfer growth from the Tryptic (Trypticase) soy broth to Simmons' citrate
agar, Tryptone (Trypticase peptone) broth and EC broth in a fermentation
tube. Incubate the Simmons' citrate agar for 24 h and Tryptone (Trypticase
peptone) broth for 48 h at 35 °C. Incubate the EC broth at 44.5 °C in a
waterbath for 24 h. The water level must be above the level of the EC broth
in the tube. Add one-half mL of Kovacs' indole reagent to the 48 h
Tryptone (Trypticase peptone) broth culture and shake the tube gently. A
positive test for indole is indicated by a deep red color which develops in
X-9
-------
the alcohol layer. E. coll is EC gas positive, indole positive, oxidase
negative, and does not grow on citrate medium.
16. Precision and Bias
16.1 Performance Characteristics
16.1.1 Precision - The degree of agreement of repeated measurements of the same
parameter expressed quantitatively as the standard deviation or as the 95%
confidence limits of the mean computed from the results of a series of
controlled determinations. The M-TEC method precision was found to be
fairly representative of what would be expected from counts with a Poisson
distribution (2).
16.1.2 Bias - The persistent positive or negative deviation of the average value of
the method from the assumed or accepted true value. The bias of the M-
TEC method has been reported to be -2% of the true value (2).
16.1.3 Specificity - The ability of a method to select and/or distinguish the target
bacteria under test from other bacteria in the same water sample. The
specificity characteristic of a method is usually reported as the percent of
false-positive and false-negative results. The false-positive rate reported for
M-TEC medium averaged 9% for marine and fresh water samples. Less
than 1% of the E. coli colonies observed gave a false-negative reaction (2).
16.1.4 Upper Counting Limit (UCL) - That colony count above which there is
an unacceptable counting error. The error may be due to overcrowding or
antibiosis. The UCL for E. coli on M-TEC medium has been reported as 80
colonies per filter (2).
162 Collaborative Study Data
16.2.1 A collaborative study was conducted among eleven volunteer laboratories,
each with two analysts who independently tested local fresh and marine
recreational waters and sewage treatment plant effluent samples, in dupli-
cate The data were reported to the Environmental Monitoring and
Support Laboratory - Cincinnati, Ohio, U.S. Environmental Protection
Agency, for statistical calculations.
16.2.2 The results of the study are shown in Figure X-l where S0 equals standard
deviation among replicate counts from a single analyst and Sb equals
standard deviation between means of duplicates from analysts in the same
X-10
-------
Figure X-l. Precision Estimates forE. coliin Water by the Membrane Filter M-TEC Method
S0 = Standard Deviation among Replicate Counts from a Single Analyst
SB = Standard Deviation between the Means of Duplicate Counts by Analysts
in the Same Laboratory
25
st
•••»
« 20
15
10
0
0 10 20 30 40 50 60 70 80 90 100
Average Colony Count Per Plate
-------
laboratory. The precision estimates from this study did not show any difference
among the water types analyzed.
16.2.3 The precision of the method can be generalized as:
S0 = 0.028 count/100 mL + 6.11 (dilution factor) and
Sb = 0.233 count/100 mL + 0.82 (dilution factor), where the
j-i • r- 10°
dilution factor =
VOLUME OF ORIGINAL SAMPLE FILTERED
16.2.4 Because of the instability of microbial populations in water samples, each
laboratory analyzed its own sample series and no full measure of recovery or
bias was possible. However, all laboratories analyzed a single surrogate sample
prepared from a freeze-dried culture of E. coli. The mean count (x) and the
overall standard deviation of the counts (St) (which includes the variability
among laboratories for this standardized E. coli sample) were 31.6
colonies/membrane and 7.61 colonies/membrane, respectively.
17. REFERENCES
1. Cabelli, V.J., A.P. Dufour, M.A. Levin, L.J. McCabe, and P.W. Haberman. 1979.
Relationship of Microbial Indicators to Health Effects at Marine Bathing Beaches. Amer.
Jour. Public Health 69:690-696.
2. Dufour, A.P., E. Strickland, and VJ. Cabelli. 1981. Membrane Filter Method for
Enumerating Escherichia coli. Appl. and Environ. Microbiol. 41:1152-1158.
3. Reagent Chemicals. 1981. American Chemical Society Specifications, 6th Edition, Am.
Chem. Soc., Washington, D.C. For suggestions on the testing of reagents not listed by
the American Chemical Society, see Reagent Chemicals and Standards. 1967. Joseph
Rosin, D. Van Nostrand Co., Inc., Princeton, N.J., and the United States Pharmacopeia,
Nineteenth Edition. 1974. United States Pharmacopeial Convention, Inc., Rockville, Md.
4. Annual Book of ASTM Standards. 1985. Vol. 1101, Water, American Society for
Testing and Materials, Philadelphia, PA.
5. Bordner, R., J.A. Winter and P.V. Scarpino (eds.). 1978. Microbiological Methods for
Monitoring the Environment. Water and Wastes, EPA-600/8-78-077, U.S. Environmen-
tal Protection Agency, Office of Research and Development, Environmental Monitoring
Support Laboratory - Cincinnati, Cincinnati, Ohio.
X-12
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SECTION XL MEMBRANE FILTER METHOD FOR C. perfringens
1. Scope and Application
1.1 This procedure enumerates Clostridiumperfringens spores from surface and
drinking water. Since C. perfringens is present in large numbers in human and
animal wastes and its spores are resistant to wastewater treatment practices,
extremes in temperature and environmental stress, it is an indicator of present fecal
contamination as well as a conservative tracer of past fecal contamination. Some
investigators have proposed C. perfringens as an indicator of the presence and the
density of pathogenic viruses and possibly other microorganisms.
1.2 It is the user's responsibility to insure the validity of this method for untested
matrices.
2. Summary of Method - An appropriate volume of water sample is passed through a
membrane filter that retains the bacteria present in the sample. The membrane filter is
placed on mCP agar and incubated anaerobically for 24 h at 44.5 °C using a medium
modified by Armon and Payment from Bisson and Cabelli (1,2). Upon exposure to
ammonium hydroxide, the yellow straw-colored C. perfringens colonies turn dark pink to
magenta and are counted as presumptive C. perfringens. Because of the selectivity of the
mCP medium, a presumptive count is normally reported for routine monitoring purposes.
Verification is not required for ICR monitoring, but if desired, colonies are confirmed by
anaerobic growth in thioglycollate, a positive gram stain reaction and stormy fermentation
of iron milk. The mCP counts are adjusted based on the percent confirmation. This
method was originally prepared by Irwin Katz, U.S. EPA Region 2 for ASTM Subcom-
mittee D19.24, Water Microbiology.
3. Definitions
3.1 C. perfringens - An obligate anaerobic gram-positive, spore forming, non-motile
bacillus that ferments lactose with stormy gas production and ferments sucrose but
does not ferment cellobiose. C. perfringens produces acid phosphatase and also
produces exotoxins which cause gas gangrene and gastroenteritis.
3.2 Spores - C. perfringens produces single oval subterminal spores less than 1 |im in
diameter during adverse conditions. Sporulation can also occur in the intestinal
tract. The endospore that develops is a highly refractile body formed within the
cell. Spores are resistant to heat, drying and chemical disinfectants, which would
kill the vegetative cells of C. perfringens. This resistance to unfavorable conditions
preserves the organisms for long periods of time.
XI-1
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4. Interferences
4.1 Waters containing sediment or large quantities of colloidal or suspended materials
such as iron, manganese, alum floe or algae can clog the filter pores and prevent
filtration, or can cause the development of spreading bacterial colonies that mask
other colonies and prevent accurate counting.
4.2 When bacterial densities are high, a smaller sample volume or sample dilution can
be filtered to minimize the interference of turbidity or high background (non-target)
bacterial densities. Replicates of smaller sample volumes or dilutions of sample
may be filtered and the results combined. However, the membrane filter technique
may not be applicable to highly turbid waters with low Clostridium densities.
4.3 Toxic materials such as metals, phenols, acids, caustics, chloramines, and other
disinfection by-products may also adversely affect recovery of Clostridium vegeta-
tive cells on the membrane filter. Although most probable number (MPN) methods
are not usually expected to generate results comparable to membrane filter meth-
ods, an MPN method should be considered as an alternative procedure if the
membrane filter method is not useable for these samples (3).
4.4 Some lots of membrane filters produce low recoveries or poor differentiation of
target and non-target colonies due to toxicity, chemical composition, or structural
defects. Quality control checks should be made on new lots of membranes (4).
5. Health and Safety
5.1 This method does not address all safety problems associated with its use. It is the
responsibility of the user to establish appropriate safety and health practices and
determine regulatory limitations prior to use.
5.2 The analyst/technician must know and observe normal good laboratory practices
and safety procedures required in a microbiology laboratory while preparing, using
and disposing of cultures, reagents and materials and while operating sterilizers and
other equipment and instrumentation.
5.3 Mouth-pipetting is not permitted.
XI-2
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6. Instruments. Equipment and Supplies
6.1 Sample container, sterile, non-toxic glass or rigid plastic with screw cap, or plastic
bag, minimum of 125 mL capacity.
6.2 Pipet container, stainless steel, or aluminum, for sterilization and storage of glass
pipets.
6.3 Pipets, sterile T.D. bacteriological or Mohr, glass or plastic, of appropriate volumes.
6.4 Graduated cylinders, 100 to 1000 mL, tops are covered with aluminum foil or kraft
paper and sterilized.
6.5 Bottles, milk dilution, borosilicate glass or non-toxic heat stable plastic, screw-cap
with neoprene liners, marked at 99 mL for 1:100 dilutions. Dilution bottles marked
at 90 mL or tubes marked at 9 mL may be used for 1:10 dilutions.
6.6 Membrane filtration units, (filter base and funnel), glass, plastic or stainless steel,
wrapped with aluminum foil or kraft paper and sterilized.
6.7 Membrane Filters - sterile, white, grid marked, 47 mm diameter, with 0.45 ± 0.02
|im pore size or other pore sizes for which the manufacturer provides data demon-
strating equivalency.
6.8 Ultraviolet unit for disinfecting the filter funnel between filtrations in a series
(optional).
6.9 Line vacuum, electric vacuum pump or aspirator as a vacuum source.
6.10 Flask, vacuum, usually 1 L, with appropriate tubing, to hold filter base. Filter
manifolds to hold a number of filter bases are optional.
6.11 Flask, safety trap, placed between the filter flask and the vacuum source.
6.12 Forceps, straight or curved, with smooth tips to permit handling of filters without
damage.
6.13 Petri plates, plastic or glass, 50 x 9 mm, with tight-fitting lids, or 60 x 12 mm, with
loose fitting lids (dimensions are nominal).
6.14 Test Tubes, 20 x 150 mm, borosilicate glass or disposable plastic.
6.15 Caps, aluminum or autoclavable plastic, for 20 x 150 mm test tubes.
XI-3
-------
6.16 Test Tubes, screw cap, 16 x 125 mm or other appropriate size.
6.17 Inoculation loops, 3 mm diameter, and needles, nichrome or platinum wire, 26 B &
S gauge, in suitable holders. Sterile disposable applicator sticks or plastic loops are
acceptable alternatives to inoculation loops.
6.18 Thermometers, 0-50°C, graduated to 0.2 degrees, and 0-100°C for heat shock
which has been checked against the appropriate National Institute of Standards and
Technology (NIST) certified thermometer, or against a thermometer traceable to
NIST.
6.19 Waterbath, that maintains 46-48 °C for tempering agar.
6.20 Waterbath with gable cover that maintains 60°C ± 0.5 °C for heat shocking
samples.
6.21 Anaerobic system (anaerobic jar, reaction chamber, hydrogen/carbon dioxide
disposable generator and anaerobic indicator), or any other system capable of
producing the appropriate anaerobic conditions to support the growth of the
organisms1.
6.22 Filter Paper, circular, 11 cm, Whatman 40 or 110, or equivalent, for separation of
mCP agar plates during anaerobic incubation.
6.23 Incubator, that maintains 44.5 °C ± 0.2°C and is large enough to hold the anaerobic
chamber.
6.24 Incubator, Water Bath, that maintains 44.5 °C ± 0.2°C for incubation of Iron Milk
Medium.
6.25 Microscope, stereoscopic, wide-field type, with magnification of 10 to 15X.
6.26 Microscope lamp, that produces diffuse light from a cool white fluorescent or
tungsten lamp adjusted to give maximum visibility.
6.27 Counting device, hand tally or electronic.
'BBL 60460 or BBL 60466 GASPAK Anaerobic System with BBL 70308 Disposable
Hydrogen and Carbon Dioxide Generator Envelopes, BBL Microbiological Systems,
Cockeysville, MD 21030, or equivalent.
XI-4
-------
6.28 Sonication unit, to aid in dissolving reagents.2
7. Reagents. Standards and Media
7.1 Purity of Reagents - Use reagent grade chemicals in all tests. Unless otherwise
indicated, all reagents must conform to the specifications of the Committee on
Analytical Reagents of the American Chemical Society where such specifications
are available (5). Other grades may be used, provided it is first ascertained that the
reagent is of sufficiently high purity to permit its use without lessening the accuracy
of the determination. Use microbiological grade agar in preparation of culture
media. Whenever possible, use commercial culture media as a means of improved
quality control.
7.2 Purity of Water - Unless otherwise indicated, references to water mean reagent
water as defined by Type II of Specification Dl 193 (6).
7.3 Buffered Dilution and Rinse Water
7.3.1 Phosphate Buffer Dilution Water
7.3.1.1 Stock Phosphate Buffer Solution - Dissolve 34.0 g of potassium
dihydrogen phosphate (KH2PO4) in 500 mL of water. Adjust pH to
7.2 with 1 N NaOH and bring to 1000 mL with water. Dispense
aseptically into screw-cap bottles and autoclave for 15 min at 121 °C.
Alternatively, sterilize by filtration through a 0.2 jim pore membrane
filter and dispense aseptically into sterile screw-cap bottles. Store in
refrigerator and handle aseptically. If cloudiness, a marked change in
pH, or other evidence of contamination appears, discard the stock.
Confirm that pH is 7.2 ± 0.5 before use.
7.3.1.2 Magnesium Chloride Solution - Dissolve 81.4 g of hexahydrate
magnesium chloride (MgCl2-6H20) in 1000 mL of water. Mix well
and sterilize by filtration or autoclave for 15 min at 121 °C. Store in
refrigerator and handle aseptically. If cloudiness, or other evidence of
contamination occurs, discard the stock solution.
7.3.1.3 Phosphate Buffered Dilution Water - Add 1.25 mL of stock phos-
phate buffer solution and 5 mL of magnesium chloride solution to
1000 mL of water in a volumetric flask and mix well. Dispense
dilution water in amounts which will provide 99 ± 2 mL after sterili-
2Bronson Sonifier, 500 W, or Tekmar Sonic Disrupter, 500 W with 3 mm tip set at 18
W, or equivalent.
XI-5
-------
zation in screw-cap dilution bottles, or in larger volume containers for
use as rinse water. Autoclave dilution bottles for 15 min at 121 °C.
Autoclave larger volumes for longer periods as appropriate. Alterna-
tively, sterilize by filtration through a sterile 0.2 jim pore membrane
filter unit and dispense aseptically into sterile screw-cap bottles.
7.3.2 Peptone Dilution and Rinse Water - Dissolve 1.0 g of peptone3 in 100
mL of water, and bring to 1000 mL with water. Dispense in screw-cap
bottles in volumes to produce 99 ± 2 mL after autoclaving. Autoclave for
15 min. at 121°C. Final pH should be 6.8 - 7.0. Adjust as necessary.
7.4 Ethanol - 95%, pure, for flame-sterilization of forceps and for preparation of
acetone alcohol for gram stain.
7.5 Ammonium Hydroxide Solution (29.2% NH4OH) - commercially available.
7.6 Ferric Chloride Solution - Weigh out 4.5 g of FeCl3-6H20 and dissolve in 100
mL of water. Filter sterilize and store in refrigerator.
7.7 Phenolphthalein diphosphate Solution - Weigh out 0.5 g of phenolphthalein
diphosphate and dissolve in 100 mL of water. Filter sterilize and store in refrigera-
tor.
7.8 Indoxyl p-D Glucoside Solution - Weigh out 0.06 g of Indoxyl p-D Glucoside
and dissolve in 80 mL of water (0.075 solution). Sonicator (item 6.28) can be used
to speed dissolution. Filter-sterilize and use in 7.9.2.
7.9 Modified mCP Agar (1)
7.9.1 Composition/L
Tryptose 30.0 g
Yeast Extract 20.0 g
Sucrose 5.0 g
L-cysteine Hydrochloride 1.0 g
MgSO4-7H20 0.1 g
Bromcresol Purple 0.04 g
Agar 15.0 g
7.9.2 Preparation of Modified mCP Agar: Add medium ingredients from
7.9.1 to 900 mL water in a liter Erlenmeyer flask. Stir and heat to dissolve
in a boiling water bath. Bring the pH to 7.6 with 1 N NaOH. Autoclave for
3Peptone (Difco 0118), Difco Laboratories, Detroit, MI, or equivalent.
XI-6
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15 min at 121 °C (15 Ibs pressure). Cool to 50°C. Add the following
reagents aseptically and mix well:
D-cycloserine 0.4 g
Polymyxin B sulfate 0.025 g
4.5% FeCl3-6H20 solution 2.0 mL
0.5% Phenolphthalein diphosphate solution 20.0 mL
0.075% Indoxyl-p-D-Glucoside solution 80.0 mL
7.9.3 Dispense 4-4.5 mL into each petri plate using a sterile Cornwall syringe or
Brewer pipette. Store agar plates inverted in a plastic bag in a refrigerator
for no more than one month. It is recommended that the plates be stored in
an anaerobic chamber in the refrigerator for optimal preservation.
710 Modified Iron Milk Medium (7)
7.10.1 Composition/L
Fresh pasteurized, homogenized milk
(3.5%butterfat) 1.0 L
FeSO4-7H2O 1.0 g
7.10.2 Preparation: Dissolve ferrous sulfate in 50 mL water. Add slowly to 1 L
milk and mix with magnetic stirrer. Dispense 11 mL of medium into
culture tubes. Cap and autoclave 12 min at 118°C. CAUTION: Do not
exceed the recommended time and temperature limits to avoid coagulation.
7.11 Fluid Thioglycollate Medium4
7.11.1 Composition/L
L-Cystine 0.5 g
Agar (granulated) 0.75 g
NaCl 2.5 g
Dextrose (anhydrous) 5.0 g
Yeast extract 5.0 g
Tryptone 15.0 g
Sodium thioglycollate 0.5 g
Resazurin 0.001 e
4Fluid Thioglycollate Medium (BBL 12461), Becton-Dickinson Microbiology
Systems, Cockeysville, MD; (Difco 0432-02-6) Difco Laboratories, Detroit, MI; or
equivalent.
XI-7
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7.11.2 Preparation: Suspend 29.25 g of medium in 1 L of water. Mix thor-
oughly and heat to boil for 1-2 min or until solution is complete. Final pH
is 7.1 ±0.1. Dispense 15 mL portions into culture tubes. Cap and auto-
clave for 15 min at 121 °C. Store tubes in the dark at room temperature.
Do not refrigerate. If medium becomes oxidized (more than 30% of
medium is pink), reheat once only in boiling water bath and cool before
use.
712 Gram Stain Reagents
7.12.1 Gram stain reagent kits are commercially available and are recommended.
7.12.2 Ammonium oxalate-crystal violet (Hucker's): Dissolve 2 g crystal violet
(90% dye content) in 20 mL 95% ethyl alcohol. Dissolve 0.8 g
(NH4)2C2O4-H2O in 80 mL water; mix the two solutions and age for 24 h
before use. Filter through a 0.22 jim membrane filter. Store in a glass
bottle.
7.12.3 Lugol's solution, Gram's modification: Grind 1 g iodine crystals and 2 g
KI in a mortar. Add water, a few mL at time, and grind thoroughly after
each addition until solution is complete. Filter solution through a 0.22 jim
membrane filter, and rinse into an amber glass bottle with the remaining
water (using a total of 300 mL).
7.12.4 Counterstain: Dissolve 2.5 g safranin dye in 100 mL 95% ethyl alcohol.
Add 10 mL to 100 mL water. Filter through a 0.22 jim membrane filter.
7.12.5 Acetone alcohol: Mix equal volumes of ethyl alcohol (95%) with acetone.
8. Sample Collection. Preservation and Holding Times
8.1 Collection - Water samples are collected in sterile sample containers with leak-
proof lids.
8.2 Sample Preservation and Holding Conditions - Hold water samples at a temper-
ature below 10°C during transit to the laboratory by placing them on ice, surround-
ing them with blue ice or by refrigeration. Use insulated containers to maintain
storage temperature during transit. Take care that sample bottle closures are not
submerged in water during transit or storage.
8.3 Holding Time - Refrigerate samples upon arrival in the laboratory and analyze
within 8 h after collection. C. perfringens spores can survive for extended periods
XI-8
-------
at 1-4°C. However, since a correlation is planned with other indicators, the holding
time for C. perfringens must be limited to that of the other indicators.
9. Quality Control
9.1 Adherence to sampling procedures, preservation procedures and holding time
limits is critical to the production of valid data. Reject samples if appropriate
sampling, preservation and handling procedures have not been followed
9.2 Check and record temperatures in incubators daily to insure operation within stated
limits.
9.3 Check thermometers at least annually against a National Institute of Standards and
Technology (NIST) certified thermometer or one traceable to NIST and record the
results. Examine mercury columns for separation and reunite before use. Adjust or
post correction factors on equipment.
9.4 Use a loop to inoculate mCP agar plates with pure cultures of C. perfringens and E.
coli. Carry these plates through the entire analytical procedure, as positive and
negative controls.
9.5 For general quality control recommendations, see "Quality Assurance for Microbi-
ological Analyses" in ASTM Special Technical Testing Publication 867 (8).
10. Procedure for Analyses of Water Samples for Spores
10.1 Prepare mCP Agar according to Section 7.9.
10.2 Mark the bottoms of the petri plates and laboratory data sheets with sample
identities and volumes.
10.3 Grasp a sterile membrane filter by its edge using a sterile forceps and place on the
filter base, grid side up. Attach the funnel to the base of the filter unit; the mem-
brane filter is now held between the funnel and the base.
104 Procedure for Inactivation of Vegetative Cells - To obtain a count only of C.
perfringens spores, hold water samples in a waterbath at 60°C for 15 min to kill all
vegetative cells.
10.4.1 Equilibrate a waterbath at 60 C.
10.4.2 Determine the time necessary to bring a blank sample to 60°C. Use the
same size container and volume as used for water samples.
XI-9
-------
10.4.3 Immerse the containers containing the water samples in the waterbath for
the time necessary to warm sample to 60°C plus 15 min. Do not allow the
container cap or container opening to become contaminated by water in the
bath.
10.4.4 Cool the sample containers in cold tap water immediately after heat shock
and proceed with the analyses in 10.3.
10.5 For greatest accuracy, it is necessary to filter a sample volume that will yield a
countable plate. Select sample volumes based on previous knowledge, which will
produce membrane filter plates with 20-80 C. perfringens colonies. A narrow
range of dilution factors of 4 or 5 can usually be used to achieve the desired
number of colonies. An example of such factors is shown in Table XI-1. How-
ever, if past analyses of specific samples have resulted in confluent growth or "too
numerous to count" (TNTC) membranes from excessive turbidity, additional
samples should be collected and filtration volumes adjusted to provide isolated
colonies from one or more smaller volumes. The counts from smaller volumes can
be combined for a final count/total volume filtered.
10.6 Shake the sample bottle vigorously about 25 times and measure the desired volume
of sample into the funnel with the vacuum off. To measure the sample accurately
and obtain good distribution of colonies on the filter surface, use the following
procedures:
10.6.1 Sample volumes of 20 mL or more: Measure the sample in a sterile grad-
uated cylinder and pour it into the funnel. Rinse the graduate twice with
sterile dilution water, and add the rinse water to the funnel.
10.6.2 Sample volumes of 10-20 mL: Measure the sample with a sterile 10 mL or
20 mL pipet into the funnel.
10.6.3 Sample volumes of 1-10 mL: Pour about 10 mL of sterile dilution water
into the funnel without vacuum. Add the sample to the sterile water using
appropriate sterile pipet and filter the sample.
10.6.4 Sample volumes of less than 1.0 mL: Prepare appropriate dilutions in
sterile dilution water and proceed as applicable in steps 10.6.1-10.6.3
above.
10.6.5 To reduce the chance for carryover, when analyzing a series of samples or
dilutions, filter samples in the order of increasing volumes of original
sample. The time elapsing between preparation of sample dilutions and
filtration should be minimal and never more than 30 min.
XI-10
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Table XI- 1. Sample Volumes to Obtain Colony
Count on Membrane Filters *
(Range of 20 - 80 Colonies)
Sample Volume in mL
0.05
0.20
0.80
3.20
15.00
60.00
Added as:
5.0 mL of 10'2 dilution
2.0 mL of 10'1 dilution
8.0 mL of 10'1 dilution
3.2 mL of Undiluted Sample
15.0 mL of Undiluted Sample
60.0 mL of Undiluted Sample
*The range of volumes and dilutions selected for filtration of completely
unknown samples can be broader, to provide a factor of 10 or more.
Prepare at least three sample increments.
10.7 After adding the sample to filter funnel, turn on vacuum and filter the sample.
Rinse the sides of the funnel walls at least twice with 20-30 mL of sterile dilution
water. Turn off vacuum and remove the funnel from the filter base.
10.8 Flame forceps, cool and aseptically remove the membrane filter from the filter
base. Place the filter, grid side up, on the mCP agar using a rolling motion to
prevent air bubbles. Reseat the filter if bubbles occur.
10.9 Remove the lids from mCP agar plates. Invert lids and nest them under the
corresponding plate bottom for identification. Stack the plates in layers in the
anaerobic chamber, separating each plate with sterile filter paper. Incubate the
anaerobic chamber at 44.5°C for 24 h, maintaining anaerobic conditions through
the use of a commercial anaerobic system. If visible condensation does not occur
within 60 min after the BBL GasPak is activated, the reaction should be terminated
by opening the jar, and removing the GasPak. Inspect the chamber seal for
alignment and lubricant. Insert a new GasPak and seal the chamber. The dispos-
able anaerobic indicator (moistened flat fiber wick impregnated with 0.35%
methylene blue solution) is white to pale blue upon opening foil envelope. It turns
blue upon exposure to air. Under anaerobic conditions the methylene blue indica-
tor will decolorize (turn white) within 2 - 4 h. It should remain white through the
incubation period.
10.10 After 24 h, remove one agar plate at a time from the chamber and reclose the
chamber. Examine the mCP plate for straw-yellow colonies. If such colonies are
XI-11
-------
present, invert and expose the open agar plate 10-30 sec to the fumes from an open
container of concentrated ammonium hydroxide.
10.11 If C. perfringens colonies are present, the phosphate in the phenolphthalein
diphosphate will be cleaved from the substrate by acid phosphatase and typical
colonies of C. perfringens will turn a dark pink or magenta after exposure to fumes
of ammonium hydroxide.
10.12 Count pink or magenta colonies as presumptive C. perfringens.
10.13 Repeat steps 10.10 to 10.12 with the other culture plates.
11. Confirmation Tests
11.1 Pick at least 10 typical isolated C. perfringens colonies from the mCP plate and
transfer each into a separate thiogly coll ate tube. Incubate at 35 °C for 24 h.
Examine by gram stain and for purity. C. perfringens are short gram-positive
bacilli. Retain tubes for further testing.
11.2 Inoculate ten tubes of iron milk medium with 1 mL from the ten fluid thiogly collate
tubes and incubate in a 44.5 °C waterbath for two h. Examine hourly for stormy
fermentation with rapid coagulation and fractured rising curd.
11.3 Those colonies which are gram-positive, non-motile, and produce stormy fermenta-
tion of milk in these confirmatory tests are considered confirmed C. perfringens.
12. Data Analyses. Calculations and Reporting Results
12.1 Pink or magenta colonies counted on mCP medium are adjusted to a count/100 mL
and reported as: Presumptive C. perfringens colony forming units (CFU)/100 mL.
The presumptive count is normally used for routine monitoring.
12.2 If confirmation tests are performed, original counts on mCP agar are adjusted
based on the percent of colonies picked and confirmed. Report as confirmed C.
perfringens CFU/100 mL of water sample.
13. Method Performance Characteristics
13.1 The detection limit is one C. perfringens CPU per sample volume or sample
dilution tested.
XI-12
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13.2 The false positive rate is reported to be 7-9% by Bisson and Cabelli (2) and Fujioka
and Shizumura (10). The false negative rate is reported to be 3% by Fujioka and
Shizumura (10).
13.3 The single laboratory recovery is reported to be 79-90% by Bisson and Cabelli (2).
13.4 In a collaborative study, sixteen analysts from nine laboratories analyzed a sedi-
ment, a non-chlorinated wastewater and three spiked waters (marine water, lake
water and a finished drinking water), as unknowns. Analysts were provided range
values to reduce the number of dilutions necessary for the analyses.
13.4.1 The single operator precision as % Relative Standard Deviation (RSD)
ranged from 14-28% while the overall precision (as % RSD) ranged from
24-41%, for St/S0 (overall precision/single operation precision) ratios of
1.13-1.80. The larger RSD values were not generated with the more
difficult sample matrices of sediment and wastewater. Rather, they oc-
curred with the seeded finished drinking water sample and are believed to
have been caused by overestimates of the concentration of C. perfringens,
which resulted in marginally low plate counts with inherently greater
deviations. Overall, the St and S0 values were similar across sample types
and concentration levels of C. perfringens.
13.4.2 Although there were no "standards" available for this RR study, sample 5,
a seeded drinking water, had a reference count of 78 C. perfringens
CFU/100 mL. The laboratories in this study achieved a mean recovery of
67 CFU from Sample 5 for an 86 percent recovery.
13.4.3 Table XI-2 contains the statistical summary of the collaborative study
results.
Table XI-2. Statistical Evaluation of Results (CFU/100 mL)
(After Rejection of Outliers)
Sample
1
2
O
4
5
Initial n
30
36
30
36
27
Final n
30
35
30
35
27
X
2893.63
108.09
73.07
5985.71
67.22
S0
397.78
20.34
20.29
1400.70
18.64
s,
715.45
26.18
23.23
1585.80
27.60
%RSD
(S0)
13.75
18.82
27.77
23.40
27.73
%RSD
(St)
24.73
24.22
31.79
26.49
41.06
XI-13
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14. Pollution Prevention
14.1 Pollution prevention is any technique that reduces or eliminates the quantity or
toxicity of waste at the point of generation. It is the environmental management
tool preferred over waste disposal or recycling. When feasible, laboratory staff
should use a pollution prevention technique such as preparation of the smallest
practical volumes of reagents, standards and media or downsizing of the test units
in a method.
14.2 The laboratory staff should also review the procurement and use of equipment and
supplies for other ways to reduce waste and prevent pollution. Recycling should be
considered whenever practical.
15. Waste Management - The Environmental Protection Agency requires that laboratory
waste management practices be conducted consistent with all applicable rules and
regulations. The Agency urges laboratories to protect the air, water and land by minimiz-
ing and controlling releases from hoods and bench operations, complying with the letter
and spirit of sewer discharge permits and regulations and by complying with solid and
hazardous waste regulations, particularly the hazardous waste identification rules and land
disposal restrictions.
16. Key Words - Clostridium., Clostridium perfringens., anaerobic bacteria, spore-forming
bacteria, indicator organisms, pollution, water quality.
17. References:
1. Armon, R. and P. Payment, 1988. A modified mCP Medium for enumerating
Clostridiumperfringens from Water Samples. Can. J. Microbiol. 34: 78-79.
2. Bisson, J.W., and VJ. Cabelli, 1979. membrane filter enumeration method for
Clostridium perfringens, Appl. Environ. Microbiol. 37:55-66.
3. St. John, W.D., J.R. Matches, and M.M. Wekell, 1982. Use of iron milk medium for
enumeration of Clostridium perfringens. J. Assoc. Off. Anal. Chem. 65:1129-1133.
4. Brenner, K. and C. Rankin, 1990. New Screening Test to Determine the Acceptabil-
ity of 0.45 |im Membrane Filters of Analysis of Water, Appl. Environ. Microbiol.,
56:54-64.
5. Reagent Chemicals, American Chemical Society Specifications, American Chemical
Society, Washington, DC. For suggestions on testing reagents not listed by the
American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH
LTD, Poole, Dorset, U.K. and the United States Pharmacopeia.
XI-14
-------
6. American Society for Testing and Materials, Annual Book of ASTM Standards, Vol.
11.01. ASTM, Philadelphia, PA 19103-1187.
7. FDA Bacteriological Analytical Manual, 7th Ed., AOAC International, Arlington,
VA, 1992, Iron Milk Medium (modified), 476-477.
8. Bordner, R.H., J.A. Winter and P.V. Scarpino (eds.), 1978. Microbiological Meth-
ods for Monitoring the Environment, Water and Wastes, EPA-600/8-78-017, U.S.
Environmental Monitoring and Support Laboratory, Cincinnati, Ohio, 5-31 or
Bordner, R., 1985. Quality Assurance for Microbiological Analyses of Water, in:
Quality Assurance for Environmental Measurements . ASTM STP 867, Ameri-
can Society for Testing and Materials, Philadelphia, PA, pp. 133-143.5
9. Standard Methods for the Examination of Water and Wastewater, 18th ed. 1992.
APHA, Washington, D.C., 1992, Sections 9060A and 9060B.
10. Fujioka, R.S. and Shizumura, L.K. 1985. Clostridiumperfringens, A Reliable
Indicator of Stream Water Quality, JWPCF, 57:986-992.
XI-15
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APPENDIX A. VERIFICATION OF STATE CERTIFICATION
Please complete the following:
Laboratory Name:
Address:
City:
Contact Person:
Telephone: ( )
Laboratory Type: Utility:
State:
Zip:
Commercial:
State:
Other:
Certification: The information requested in this section is necessary to verify the
Drinking Water Laboratory certifications listed below. Please fill-out completely and
supply all requested documentation.
ANALYTICAL
METHODS
PERFORMED
TC-MF
TC-MTF
FC-MF
FC-MTF
EC + MUG
ONPG - MUG
NA + MUG
(Indicate
Methods
Performed
with a /)
STATE(S)
in Which
Certified
CERTIFICATION
Type
Certification Date
Please attach a copy of your current letter(s) or certificate(s) of approval for conducting
the above analyses and return to:
ICR Laboratory Coordinator
U.S. EPA, OGWDW
Technical Support Division
26 West Martin Luther King Drive
Cincinnati, Ohio 45268
ApA-1
-------
APPENDIX B. APPLICATION FOR LABORATORY APPROVAL
FOR THE INFORMATION COLLECTION RULE (ICR)
The U.S. Environmental Protection Agency (EPA) is proposing to require public water
systems which serve 10,000 people or greater to generate and provide the Agency with
specific monitoring data and other information characterizing their systems. Depending on the
population served, systems which use surface water, or ground water under the direct influence
of surface water, would be required to monitor their source water at the intake of each plant for
two disease-causing protozoa, Giardia and Cryptosporidium, total coliforms and fecal
coliforms or Escherichia coli. Systems which serve more than 100,000 people would be
required to monitor their source water at the intake of each plant for the microorganisms
indicated above, plus total culturable viruses. When pathogen levels equal or exceed one virus
or protozoan per liter in the source water, systems would also be required to monitor their
finished waters for these microorganisms.
Laboratories monitoring for protozoa and viruses would have to be approved by the U.S.
EPA. The attached information describes the minimal requirements for approval to perform
protozoan and/or virus analyses under the Information Collection Rule. Accepted applicants
will also be required to demonstrate capabilities based on analyses of unknown samples and an
on-site inspection of their facility.
Those interested in being approved must first demonstrate their qualifications by complet-
ing the attached application(s) and forwarding it (them) to:
ICR Laboratory Coordinator
U.S. Environmental Protection Agency
Office of Ground Water and Drinking Water
Technical Support Division
26 West Martin Luther King Drive
Cincinnati, Ohio 45268
Qualified applicants will be provided a copy of the ICR Microbial Laboratory Manual
describing fully the approval requirements.
Since total coliform and fecal coliform/E1. coli analyses proposed under the ICR are
required under the Drinking Water Laboratory Certification Program, laboratory approval for
these analyses is not required under the ICR if State certification can be verified (see Appen-
dix A).
ApB-1
-------
MINIMAL REQUIREMENTS FOR VIRUS LABORATORIES
Background Information:
For ICR approval, the virus analytical laboratories must have suitable facilities, equip-
ment, instrumentation, and an ongoing quality assurance (QA) program. Analysts must be
experienced in viral analyses and meet performance evaluation criteria. As laboratories are
approved, the U.S. EPA will provide an updated list of those laboratories with Agency
approved analysts to the public water systems that serve a population of 100,000 or more.
Analytical Methods:
The proposed virus protocol was published in the Federal Register. Vol. 59, No. 28,
February 10, 1994, 40 CFRPart 141 Monitoring Requirements For Public Drinking
Water Supplies; Proposed Rule; pp. 6430-6444. The final draft method will be provided to
those applicants that meet the minimal requirements set forth in this document. The final
method will be available at the time the ICR is promulgated.
Sample Collection:
Each analytical laboratory will be responsible for procuring, assembling, sterilizing, and
transporting the sample collection apparatus to the water system. Systems will be advised on
proper collection techniques by the analytical laboratory in accordance with the procedures in
the ICR virus protocol. A virus sampling video will be available to the system to reinforce
instructions received from the analytical laboratory.
Approval of an Analytical Laboratory:
The minimal requirements for personnel (education; training or equivalent experience),
facilities, equipment and instrumentation, QA/quality control (QC), etc. listed below must be
met and documented in the application before the laboratory and analysts will be judged
qualified to be considered for approval. If the above criteria are met, ICR approval to perform
analyses will require: 1) successful performance on QC samples, as defined in the virus
protocol, 2) satisfactory analyses on unknown performance evaluation (PE) samples, and 3) an
on-site evaluation of the laboratory and the analyst(s).
QC Samples/Cell Line:
EPA will provide QC samples containing known virus concentrations to laboratories
meeting minimal requirements. These samples are to be used initially and periodically
thereafter to demonstrate the analyst(s)' ability to process and analyze samples correctly.
Buffalo green monkey (BGM) cells will be provided to establish uniform cell cultures in all
laboratories.
ApB-2
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Minimal Requirements:
1. Personnel:
Principal Analyst/Supervisor: To be qualified for approval, a laboratory must have
a principal analyst who may also serve as a supervisor if an additional analyst(s) is to be
involved. The principal analyst/supervisor oversees or performs the entire analyses and
carries out QC performance checks on technicians and/or other analyst(s). This person
must be an experienced microbiologist with at least a B.A./B.S. degree in microbiology or
a closely related field and a minimum of three years continuous bench experience in cell
culture propagation, processing of virus samples, and animal virus analyses. This analyst
must have analyzed a PE sample set using the ICR virus method and results must fall
within acceptance limits. Also, the principal analyst must demonstrate acceptable
performance during an on-site evaluation by U.S. EPA personnel.
Analyst: This person(s) performs at the bench level under the supervision of a
principal analyst and can be involved in all aspects of analysis, including preparation of
sampling equipment, filter extraction, sample processing, cell culture, virus assay, and
data handling. The analyst must have two years of college lecture and laboratory course
work in microbiology or a closely related field. The analyst must have at least six months
bench experience in cell culture and animal virus analyses, including three months
experience in filter extraction of virus samples and sample processing. Six months of
additional bench experience in the above areas may be substituted for the two years of
college. Each analyst must have analyzed a PE sample set using the ICR virus method
and results must fall within acceptance limits. The analyst must also demonstrate
acceptable performance during an on-site evaluation.
Technician: This person extracts filters and processes the samples under the
supervision of an analyst, but does not perform cell culture work, virus detection or
enumeration. The technician must have at least three months experience in filter extrac-
tion and processing of virus samples.
2. Laboratory Facilities: Laboratories must have an air system regulated for temperature,
humidity and air cleanliness. Laboratories should be maintained under negative air pressure to
protect against accidental release of viral pathogens and should be equipped with ultraviolet
lights for decontamination of rooms during periods when personnel are absent. Laboratories
should maintain separate rooms for preparing cell cultures and processing virus samples.
However, in the absence of separate rooms, laminar flow hoods must be used for cell culture
preparation to prevent contamination. Freezers, incubators, and other large instruments should
be in rooms where they can be accessed without disturbing ongoing laboratory efforts. The
area provided for preparation and sterilization of media, glassware, and equipment should be
separate from other laboratory work areas, but close enough for convenience. Visitors and
through traffic must be minimized in work areas. ICR samples will be archived for future
ApB-3
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testing by polymerase chain reaction (PCR) methods which are sensitive to contamination.
Therefore, rooms for processing and assaying ICR samples must not have been used for
analyzing PCR products. For ICR studies, the minimal area recommended for each worker is
six to ten linear feet of usable bench space per analyst, exclusive of areas requiring specialized
equipment or used for preparatory and supportive activities. Bench tops should be stainless
steel, epoxy plastic, or other smooth impervious material that is inert and corrosion-resistant.
Laboratory lighting should be even, screened to reduce glare, and provide about 100 foot-
candles of light intensity on working surfaces.
High standards of cleanliness must be maintained in work areas. Laboratory bench surface
cleanliness and laboratory air quality must be monitored. The laboratory must have a pest
control program that includes preventive measures such as general cleanliness and prompt
disposal of waste materials. The laboratory must be in compliance with all applicable judicial
ordinances and laws for the managing and disposal of pathogenic agents.
3. Laboratory Equipment And Instrumentation: The laboratory must be equipped on-
site with the instrumentation and equipment needed to perform the virus sample collection,
extraction, concentration and assay as set forth in the ICR virus protocol. Included are
incubators, water baths, hot air sterilizing ovens, autoclaves, refrigerators with -20°C freezer
compartment, -70°C deep freezers, reagent grade water supply, balances, pH meter, centri-
fuges, temperature recording devices, and both upright and inverted microscopes. Laminar
flow hoods and UV lights are strongly recommended as added equipment within the analytical
laboratory.
4. Safety: Laboratory must meet Biosafety Level 2 Criteria as described in Biosafety in
Microbiological and Biomedical Laboratories, 3rd Ed., HHS Publication No. (CDC) 93-
8395. U.S. Government Printing Office, May, 1993. Immunocompromised individuals
must not work in or be admitted to this area.
5. QA/QC Procedures: A formal QA document must be prepared and should follow the
guidelines for a laboratory QA Plan, p. 7 in the Manual for the Certification of Laboratories
Analyzing Drinking Water. 1990, U. S. Environmental Protection Agency Publication No.
EPA/570/9-90/008, 3rd Ed., Washington, D.C., and Section II of this Manual. Laboratories
must have a written QA program that applies practices necessary to minimize errors in
laboratory operations that are attributable to personnel, equipment, supplies, processing
procedures, or analytical methods. These include records of routine monitoring of equipment
and instrumentation performance. Records of QC checks must be available to the U.S. EPA
for inspection. The procedures for preparation of reagents and cell cultures and performance
of the method must be followed exactly as written in the U.S. EPA ICR virus method.
Reagents must be stored no longer than the designated shelf life.
6. Record-Keeping And Data Reporting: A record system must be in use for tracking the
samples from sample collection through log-in, analyses and data reporting.
ApB-4
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INFORMATION COLLECTION RULE
APPLICATION FOR APPROVAL OF VIRUS LABORATORIES AND ANALYSTS 1
Laboratory:
Address:
City: State: Zip:
Contact Person:
Title:
Telephone: ( ) Fax: ( )
Type of Laboratory: Commercial Utility State Academic
Other (describe)
Principal Customers: Environmental Clinical Other
Type of Virus analyses: Human Animal Bacterial
Other (describe)
PERSONNEL QUALIFICATIONS
Name, education, virus analysis experience and field in which acquired (water, waste-
water, soils/sludge, shellfish, clinical, etc.)
Principal Analyst/Supervisor:
Education [University/Degree(s)]:
Experience:
JWhere additional pages are required, clearly mark them using the same headings as
in this application form.
ApB-5
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Analyst #1:
Education:
Experience:
Analyst #2:
Education:
Experience:
Analyst #3:
Education:
Experience:
Technician #1:
Education:
Experience:
Technician #2:
Education:
Experience:
Technician #3:
Education:
Experience:
ApB-6
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ON-SITE LABORATORY EQUIPMENT AND INSTRUMENTATION
ITEM
Reagent Water System
Sterilizing Oven
Incubator
Centrifuge
pH Meter
Temperature Recorder
Inverted Microscope
Upright Microscope
Autoclave
-70 °C Freezer
Refrigerator
Analytical Balance
UV Light System
Water Bath
Other(s) (describe)
Ona
Order
Number
TYPE/MODEL
Tlace a "/" in the "On Order" column next to items that are on order.
CURRENT LABORATORY PROGRAMS
Virus Method(s) (processing, assay)
Number of Analyses
Per Year Per Meth-
od and Virus
Groups Analyzed
ApB-7
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Sample Types (Matrices Tested):
Cell Culture (Mammalian):
Documented Laboratory QA Plan: Yes No_
Laboratory is in compliance with state and local ordinances and laws for handling and
disposal of pathogenic agents:
Yes No
Comments:
Estimated number of water samples that can be analyzed for virus/month using the
method:
The above application information is complete and accurate to the best of my knowl-
edge.
Laboratory Manager or Designee
Submit Application to: ICR Laboratory Coordinator
U. S. Environmental Protection Agency
Office of Ground Water and Drinking Water
Technical Support Division
26 West Martin Luther King Drive
Cincinnati, OH 45268
ApB-8
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MINIMAL REQUIREMENTS FOR PROTOZOAN LABORATORIES
Background Information:
For ICR approval, the protozoan analytical laboratories must have suitable facilities,
equipment, instrumentation, and an ongoing quality assurance (QA) program. Analysts must
be experienced in protozoan analyses and meet performance evaluation criteria. As laborato-
ries are approved, the U.S. EPA will provide an updated list of those laboratories with Agency
approved analysts to the public water systems that serve a population of 10,000 or more.
Analytical Methods:
The proposed protozoan method was published in the Federal Register. Vol. 59, No. 28,
February 10, 1994, 40 CFRPart 141 Monitoring Requirements For Public Drinking
Water Supplies; Proposed Rule; pp. 6416-6429. The final draft method will be provided to
those applicants that meet the minimum requirements set forth in this document. The final
method will be available at the time the ICR is promulgated.
Sample Collection:
Analytical laboratories will be responsible for procuring, assembling, and transporting the
sample collection apparatus to the water system. Systems will be advised on proper collection
techniques by the analytical laboratory in accordance with the procedures described in the
protozoan protocol. A sampling video will be available to the systems to reinforce instructions
received from the analytical laboratory.
Approval of the Analytical Laboratory:
The minimal requirements for personnel (education; training or equivalent experience),
facilities, instruments, QA/QC, etc. listed below must be met and documented in this applica-
tion before laboratories and analyst(s) will be judged qualified to be considered for approval.
If the above criteria are met, ICR approval to perform analyses also will require: 1) recovery of
both Giardia cysts and Cryptosporidium oocysts from QC samples, 2) satisfactory analyses on
unknown PE samples and 3) an on-site evaluation of the laboratory and the analyst(s).
QC Samples:
The U.S. EPA will provide QC samples containing known Giardia and Cryptosporidium
concentrations to laboratories meeting minimal requirements. These samples are to be used
initially and periodically thereafter to demonstrate the analyst(s)' ability to process and analyze
samples correctly.
ApB-9
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Minimal Requirements:
1. Personnel:
Principal Analyst/Supervisor: To be qualified for approval, a laboratory must have
a principal analyst who may also serve as a supervisor if an additional analyst(s) is to be
involved. The principal analyst/supervisor oversees or performs the entire analyses and
carries out QC performance checks on technicians and/or other analysts. The principal
analyst/supervisor must confirm all protozoan internal structures demonstrated at the
microscope by subordinates. This person must be an experienced microbiologist with at
least a B.A./B.S. degree in microbiology or a closely related field. The principal analyst
also must have at least one year of continuous bench experience with immunofluorescent
antibody (IF A) techniques and microscopic identification and have analyzed at least 100
water and/or wastewater samples for Giardia and/or Cryptosporidium. In addition, PE
samples must be analyzed using the ICR protozoan method and results must fall within
acceptance limits. The principal analyst/supervisor must also demonstrate acceptable
performance during an on-site evaluation.
Analyst: This person(s) performs at the bench level under the supervision of a
principal analyst/supervisor and is involved in all aspects of the analysis, including
preparation of sampling equipment, filter extraction, sample processing, microscopic
protozoan identification, and data handling. Recording presence or absence of morpho-
logical characteristics may be done by the analyst but must be confirmed by the principal
analyst. The analyst must have two years of college lecture and laboratory course work in
microbiology or a closely related field. The analyst also must have at least six months
bench experience, must have at least three months experience with IFA techniques, and
must have analyzed at least 50 water and/or wastewater samples for Giardia and/or
Cryptosporidium. Six months of additional bench experience in the above areas may be
substituted for two years of college. In addition, PE samples must be analyzed using the
ICR protozoan method and results must fall within acceptance limits. The analyst must
also demonstrate acceptable performance during an on-site evaluation.
Technician: This person extracts filters and processes the samples under the
supervision of an analyst, but does not perform microscopic protozoan detection and
identification. The technician must have at least three months experience in filter
extraction and processing of protozoa samples.
Laboratory Facilities: The laboratory must have dedicated, well-lighted bench space
commensurate with the number of samples to be analyzed. Six to ten feet of usable bench
space are required per analyst, exclusive of areas requiring specialized equipment or used for
preparatory and supportive activities. Bench tops should be stainless steel, epoxy plastic or
other smooth impervious material that is corrosion-resistant. Laboratory lighting should be
even, screened to reduce glare, and provide 100 foot-candles of light intensity on working
ApB-10
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surfaces. Laboratory floor space must be sufficient for stationary equipment such as refrigera-
tors and low-speed and large-capacity centrifuges. Facilities for washing and sterilization of
laboratory glassware, plasticware and equipment must be present. A dedicated space that can
be darkened must be available for the microscopic work. Laboratory areas should be kept free
of clutter and equipment and supplies should be stored when not in use. It is strongly recom-
mended that laboratories should be maintained under negative air pressure to protect against
accidental release of pathogens and should be equipped with ultraviolet lights for decontamina-
tion of rooms during periods when personnel are absent. High standards of cleanliness must
be maintained in work areas. The laboratory must have a pest control program that includes
preventive measures such as general cleanliness and prompt disposal of waste materials. The
laboratory must be in compliance with all applicable judicial ordinances and laws for manage-
ment and disposal of pathogenic agents.
3. Laboratory Equipment And Instrumentation: The laboratory must be equipped on-
site with a reagent water supply system, autoclave, refrigerator (4°C) with -20°C freezer
compartment, pH meter, slide-warming tray or incubator (37 ± 3°C), balance (top loader or
pan), membrane filtration equipment for epifluorescent staining, and hydrometer set. Specific
requirements for the microscope include differential interference contrast (DIG) or Hoffman
modulation optics (including 20X and 100X objectives). DIG or Hoffman modulation optics
should have epifluorescence capability. The epifluorescence vertical illuminator should have
either a 50 or 100 watt high-pressure mercury bulb with appropriate excitation and band-pass
filters (exciter filter: 450-490 nm; dichroic beam-splitting mirror: 510 nm; barrier or suppres-
sion filter: 515-520 nm) for examining fluorescein isothiocyanate-labeled specimens.
4. Safety: The laboratory must meet Biosafety Level 2 Criteria as described in Biosafety in
Microbiological and Biomedical Laboratories, 3rd Ed., HHS Publication No. (CDC) 93-
8395. U.S. Government Printing Office, May, 1993. Immunocompromised individuals
must not work in or be admitted to this area.
5. QA/QC Procedures: A formal QA document must be prepared and should follow the
guidelines for a laboratory QA Plan, p. 7 in the Manual for the Certification of Laboratories
Analyzing Drinking Water. 1990, U. S. Environmental Protection Agency Publication No.
EPA/570/9-90/008, 3rd Ed., Washington, D.C., and Section II of this Manual. Laboratories
must have a written QA program that applies QC practices necessary to minimize errors in
laboratory operations that are attributable to personnel, equipment, supplies, processing
procedures, or analytical methods. These include records of routine monitoring of equipment
and instrumentation performance. Records of all QC checks must be available to the U.S.
EPA for inspection. The procedures for the preparation of reagents and performance of the
method must be followed exactly as written in the U.S. EPA ICR protozoan method. Reagents
must be stored no longer than the designated shelf life.
6. Record-Keeping And Data Reporting: A record system must be in use for tracking the
samples from sample collection through log-in, analyses and data reporting.
ApB-11
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INFORMATION COLLECTION RULE
APPLICATION FOR APPROVAL OF PROTOZOAN LABS AND ANALYSTS
Laboratory:
Address:
City: State: Zip:
Contact Person:
Title:
Telephone: ( ) Fax: ( )
Type of Laboratory: Commercial Utility State Academic
Other (describe)
Principal Customers: Environmental Clinical Other
Type of Protozoa Giardia Cryptosporidium Entamoeba
Analyses: Other (describe)
PERSONNEL QUALIFICATIONS
Name, education, protozoan analysis experience and field in which acquired (water,
wastewater, clinical, etc.)
Principal Analyst/Supervisor:
Education [University/Degree(s)]:
Experience:
2Where additional pages are required, clearly mark them using the same headings as
in this application form.
ApB-12
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Analyst #1:
Education:
Experience:
Analyst #2:
Education:
Experience:
Analyst #3:
Education:
Experience:
Technician #1:
Education:
Experience:
Technician #2:
Education:
Experience:
Technician #3:
Education:
Experience:
ApB-13
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ON-SITE LABORATORY EQUIPMENT AND INSTRUMENTATION
ITEM
Autoclave
Refrigerator
Freezer
pH Meter
Analytical Balance
Top-loader Balance
Membrane Filtration Equip-
ment (for epifluorescent
staining)
Hydrometer Set
Reagent Grade Water Supply
Slide Warmer
Incubator
Centrifuge
Centrifuge Rotors
Other(s) (describe)
On
Order
Number
TYPE/MODEL
Place a "/" in the "On Order" column next to items that are on order.
ApB-14
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Vendor Name:
MICROSCOPE CAPABILITY
Model:
Optical Capability:
Epifluorescence
DIC
Hoffman Modulation
Mercury Lamp
FITC Cube Specs.
Yes
Yes
Yes
No
No
No
watt bulb
nm exciter filter;
nm beam splitting dichroic mirror; or
nm barrier or suppression filter
Objective
Power
Type
(Achromate, Neofluor,
oil, etc.)
Numerical
Aperture
Used with
(Epifluor,
D.I.C., etc.)
CURRENT LABORATORY PROGRAMS
Protozoan Method(s)
Number of Analyses
Per Year Per Method
ApB-15
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Sample Types (Matrices Tested):
Documented Laboratory QA Plan: Yes No_
Laboratory is in compliance with state and local ordinances and laws for handling and
disposal of pathogenic agents:
Yes No
Comments:
Estimated number of water samples that can be analyzed for protozoa/month using
the ICR method:
The above application information is complete and accurate to the best of my knowl-
edge.
Laboratory Manager or Designee
Submit Application to: ICR Laboratory Coordinator
U. S. Environmental Protection Agency
Office of Ground Water and Drinking Water
Technical Support Division
26 West Martin Luther King Drive
Cincinnati, OH 45268
ApB-16
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APPENDIX C. CHECKLIST FOR LABORATORY APPROVAL FOR
GIARDIAAND CRYPTOSPORIDIUM
ApC-l
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ICR Protozoan Laboratory Checklist
Laboratory:
Address:
City:
State:
Zip:
Type of Laboratory (Check):
Commercial:
Utility:
State:
Academic:
Other (Describe):
Principal Customers:
(Check)
Environmental:
Other (Describe):
Clinical:
Type of Protozoan
Analyses:
(Check each)
Giardia:
Cryptosporidium:
Entamoeba:
Other (describe):
Laboratory Contact Person:
Title:
Telephone:
Fax:
Principal Analyst/Supervisor Name:
Analyst Name:
Name of Person Being Evaluated:
Laboratory Evaluated by:
Date:
ApC-2
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ICR Protozoan Laboratory Checklist
Question
Are the personnel listed on the ICR approval application still with the
laboratory?
Are there any personnel in the laboratory not listed on the ICR approval
application?
Is the documentation available showing that the principal analyst/super-
visor has analyzed 100 water and/or wastewater samples for Giardia
and/or Cryptosporidiuml
Is the documentation available showing that the analyst has analyzed 50
water and/or wastewater samples for Giardia and/or Cryptosporidiunf!
Is the laboratory well lighted (approximately 100 foot-candles of light
intensity on work surfaces)?
Are 6-10 ft of bench space available per analyst?
Are the bench tops made of a smooth, impervious surface?
Is the laboratory floor space sufficient for the stationary equipment?
Is glassware washing equipment available?
Is the laboratory neatly organized with unused equipment and supplies
being stored (free of clutter)?
Are high standards of cleanliness and prompt disposal of waste materials
exhibited?
Is the laboratory equipped with ultraviolet lights and under negative air
pressure?
Does the laboratory have a reagent grade water system?
Does the laboratory have an autoclave?
Does the laboratory have a refrigerator (4°C) with a -20 °C freezer
compartment?
Does the laboratory have a pH meter associated with two or three calibra-
tion buffers?
Does the laboratory have either an incubator or slide warming table
calibrated to 37 ± 3 °C?
Answer
Yes
No
ApC-3
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ICR Protozoan Laboratory Checklist
Question
Does the laboratory have either a top loader or pan balance associated
with calibration weights?
Does the laboratory have a properly maintained and adjusted stomacher?
Does the laboratory have a Hoefer filtration manifold, model FH 255V?
Are the well weights for the Hoefer manifold well maintained?
Are the microscope slides the appropriate size?
Is the laboratory using clear nail polish to seal the coverslips to the
slides?
Are the cover slips 25 mm2 and No. IVa?
Does the laboratory have a hydrometer set covering the range 1.0-2.0?
Does the laboratory have an epifluorescent microscope equipped with
either Hoffman modulation or differential interference contrast optics?
Is the microscope easily changed from epifluorescent optics to either
Hoffman modulation or differential interference contrast optics and vice
versa?
Does the laboratory have a 20X scanning objective with a numerical
aperture of 0.6 on the microscope?
Is the microscope equipped with an ocular micrometer or some other
measuring device?
Has the ocular micrometer been calibrated in conjunction with the 20X
and the 100X objectives?
Is a table of objective calibrations near the microscope?
Does the laboratory have a stage micrometer?
Does the laboratory have a 100X objective with a numerical aperture of
1 .3 on the microscope?
Answer
Yes
No
ApC-4
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ICR Protozoan Laboratory Checklist
Question
Is the epifluorescent portion of the microscope equipped with an appro-
priate excitation and band pass filters for examining fluorescein
isothiocyanate-labeled specimens (exciter filter: 450-490 nm; dichroic
beamsplitting mirror 510 nm; barrier or suppression filter: 515-520 nm)?
Is the mercury bulb in the epifluorescent lamp house either a 50 or a 100
watt bulb?
Does the laboratory keep a log or have an hour totalizer on the trans-
former of the number of hours on the mercury bulb?
Has the mercury bulb been used longer than 100 h in the case of 50 watt
bulb or longer than 200 h in the case of a 100 watt bulb?
Can the principal analyst/supervisor establish Kohler illumination on the
microscope?
Can the analyst establish Kohler illumination on the microscope?
Can the principal analyst/supervisor focus both microscope eyepieces?
Can the analyst focus both microscope eyepieces?
Did the principal analyst/supervisor adjust the interpupillary distance?
Did the analyst adjust the interpupillary distance?
Does the laboratory have a large capacity centrifuge?
Does the laboratory have a swinging bucket rotor capable of spinning
250 ml capacity or greater screw-cap conical bottles?
Does the laboratory have a swinging bucket rotor capable of spinning 50
ml capacity conical screw-cap tubes?
Does the laboratory have a formal QA laboratory plan prepared and
ready for examination?
Does the laboratory have records of all QC checks available for inspec-
tion?
Does the laboratory have an adequate record system for tracking sam-
ples from collection through log-in, analysis and data reporting?
Answer
Yes
No
ApC-5
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ICR Protozoan Laboratory Checklist
Question
Is a positive and a negative Quality Control filter run with each week's
batch of filters being analyzed?
Is the laboratory using Commercial filters with Commercial LT-10 filter
holders or Filterite filters with Filterite filter holders?
Are the sampling filters 10 in (25.4 cm) long and 1 //m in nominal
porosity?
Is the sampling apparatus configured appropriately for raw water sam-
pling?
Is the sampling apparatus configured appropriately for finished water
sampling?
Is the sampling apparatus cleaned well before reshipment and/or use?
Does the laboratory have a checklist or set of sampling instructions
which are used, when sampling is done by someone other than labora-
tory personnel?
Are reagents well labelled with preparation dates and who prepared the
reagent?
Does the laboratory have formulation or recipe cards for the preparation
of 2.0% sodium thiosulfate, 10% neutral buffered formalin, phosphate
buffered saline, 1% sodium dodecyl sulfate solution, 1% Tween 80
solution, elution solution, 2.5 M sucrose solution, Percoll-sucrose
solution, the ethanol/glycerin dehydration series, DABCO-glycerin
mounting medium, and 1% bovine serum albumin?
Is the laboratory using Ensys's hydrofluor-combo kit for staining Giar-
dia cysts and Cryptosporidium oocysts?
Is the Ensys hydrofluor-combo kit still within the expiration time set by
the manufacturer?
Is the Percoll-sucrose solution used within a week of preparation?
Is the elution solution used within a week of preparation?
Is the DABCO-glycerin mounting medium discarded six months after
preparation?
Answer
Yes
No
ApC-6
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ICR Protozoan Laboratory Checklist
Question
Is the 1% bovine serum albumin discarded six months after preparation?
Are disposable cutting tools used to cut the sampling filter down to the
core?
Are the disposable cutting tool blades reused?
Is the sampling filter in either a glass or stainless steel pan of the appro-
priate size, while it is being cut to the core?
Are the filter fibers divided appropriately before hand washing?
Is the total hand washing time a minimum of 30 min?
Is stomacher washing done in two five minute intervals with redistri-
bution of the filter fibers between the intervals?
Is the right amount of 10% neutral buffered formalin added to the
concentrated particulates at the appropriate time?
Are the concentrated particulates diluted appropriately before the
Percoll-sucrose flotation?
Is the Percoll-sucrose gradient prepared correctly in a clear conical
centrifuge tube?
Is a centrifugation nomograph for determining relative centrifugal force
(gravities) located close to the centrifuge(s)?
Is the Percoll-sucrose gradient centrifuged correctly with slow accelera-
tion and deceleration?
Is the Percoll-sucrose gradient interface harvested appropriately after
centrifugation?
Is the final volume of the interface 5 ml, when harvesting is complete?
Are 5-mm diameter 12-well red teflon heavy coated slides used to
determine the correct sample volume per filter in the IF A staining
procedure?
Is the sample volume per filter in the IFA staining procedure done
correctly?
Answer
Yes
No
ApC-7
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ICR Protozoan Laboratory Checklist
Question
Are support and Sartorius membranes handled with blunt end forceps
initially?
Are the support and Sartorius membranes properly hydrated before
application to the manifold?
Is the Hoefer manifold properly configured and adjusted before the
addition of the support and Sartorius membranes?
Do the Sartorius membrane filters the laboratory is using have a porosity
between 0.2 and 1.2 //m?
Is a positive and a negative IFA Control using a Sartorius filter run with
each run of the manifold?
Are the Hoefer manifold wells labelled well during the staining proce-
dure?
Does the sample application to the membranes on the manifold include
rinses of the wells and membranes with 1% bovine serum albumin
before and after application?
Is the primary antibody diluted correctly with IX phosphate buffered
saline and goat serum?
Is the right amount of primary antibody applied per membrane, and is it
incubated for the correct amount of time?
Is the primary antibody rinsed away correctly before the application of
the secondary antibody?
Is the secondary antibody diluted correctly?
Is the right amount of secondary antibody applied per membrane, and is
it incubated for the correct amount of time?
Are the Hoefer manifold well weights covered with aluminum foil
during the secondary antibody incubation?
Is the secondary antibody rinsed away correctly after the incubation
period?
Is the alcohol dehydration step done correctly?
Answer
Yes
No
ApC-8
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ICR Protozoan Laboratory Checklist
Question
Are the glass slides that are to receive the membranes from the manifold
labelled in advance?
Have the labelled glass slides been prewarmed for 20-30 min with 75 //L
of 2% DABCO-glycerin before the application of the membrane?
Is a fresh, clean pair of forceps used to transfer each membrane from the
Hoefer manifold to its respective glass slide?
Is care exercised to insure that the Sartorius membranes are applied top
side up to the slide?
Are the membranes allowed to clear before application of the cover slip?
Are the membranes flattened correctly, before sealing the cover slip?
Are all the edges of the cover slip sealed well with clear nail polish?
Is sample processing data being recorded as the method is being per-
formed?
Are the finished slides stored in an appropriate "dry-box"?
Is the dry -box of slides allowed to reach room temperature before being
opened?
Is the microscope aligned and adjusted before the analysts starts scan-
ning and reading slides?
Is the scanning of the slides done appropriately, with the entire coverslip
being scanned rather than just the membrane?
Are measurements done with the 100X objective?
Is the room in which the microscope is located darkened while the
microscope is being used?
Are the positive and negative control slides examined as prescribed in
the method, including the complete examination of 3 Giardia cysts and
3 Cryptosporidium oocysts?
Can the microscopist who is reading the sample slides easily change the
optics from epifluorescence to Hoffman modulation or differential
interference contrast optics?
Answer
Yes
No
ApC-9
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ICR Protozoan Laboratory Checklist
Question
Are confirmations of internal structures within Giardia cysts and
Cryptosporidium oocysts being confirmed by a principal analyst/su-
pervisor.
Is the microscopic data being entered onto the Giardia and Crypto-
sporidium report forms appropriately?
Are the results from each sample being calculated on the provided
computer spreadsheet?
Are the computer spreadsheet files backed up on more than one disk, to
insure data are not lost in the eventuality of some hardware failure?
Are the Hoefer manifold and the stainless steel wells cleaned as pre-
scribed in the method?
Are the forceps used during the IFA staining cleaned well between uses?
Is all glassware and plasticware washed well and stored appropriately
between uses?
Answer
Yes
No
ApC-10
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ICR Protozoan Laboratory Checklist
Comments:
ApC-ll
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APPENDIX D. CHECKLIST FOR LABORATORY APPROVAL FOR
TOTAL CULTURABLE VIRUS
ApD-1
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SECTION I - LABORATORY-SPECIFIC INFORMATION
ICR Virus Laboratory Checklist
Laboratory:
Address:
City: State: Zip:
Type of Laboratory (Check):
Commercial: University: Utility: State:
Other (Describe):
Principal Custom-
ers: (Check)
Environmental: Clinical:
Other (Describe):
Laboratory Contact Person:
Title:
Telephone:
Fax:
Laboratory Evaluated by; Date;
ApD-2
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1. Qualifications of Laboratory Personnel
Name
Position/Title
ICR
Position
To Be
Evaluated
(Y/N)
Time in
Present
Position
Academic
Training/
Degree
Job Training/
Experience/
Area
-------
S - Satisfactory
Codes for Marking Checklist
U - Unsatisfactory NA- Not Applicable
Item to be evaluated
2.
2.1
2.2
2.3
2.4
2.5
2.6
3.
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
4.
4.1
Evaluation
Laboratory Facilities
Laboratory rooms are clean, and temperature and humidity con-
trolled
Lighting at bench top is adequate
Bench tops have smooth, impervious surfaces
Working space per analyst is adequate
Storage space is adequate
Work is separated by room or by microbiological hoods
Laboratory Safety
Laboratory meets and follows "laboratory biosafety level 2 guide-
lines"
Access to laboratory is limited
Lab coats are used in the laboratory
Mechanical pipetting devices are used
Food is not stored or consumed in the laboratory
Appropriate biohazard signs are placed on laboratory access doors
A written biosafety manual is followed and available for inspection
Laboratory personnel are adequately trained
Laboratory has provision for disposal of microbiological wastes
Laboratory Equipment and Supplies
Laboratory pH Meter
Manufacturer Model
4.1.1 Accuracy ±0.1 units; scale graduations, 0. 1 units
4.1.2 pH buffer solution aliquots are used only once
4.1.3 Electrodes are maintained according to manufacturer's rec-
ommendations
ApD-4
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Item to be evaluated
QC
4.2
4.1.4
4.1.5
Commercial buffer solutions are dated when received and
discarded before expiration date
A record of pH measurements and calibrations used is
maintained
Evaluation
Light Microscope
Manufacturer
4.3
4.2.1
4.2.2
Model
Microscope is equipped with lenses to provide about 40X -
100X total magnification
Optical clarity is good
Inverted Light Microscope
Manufacturer
4.4
4.3.1
4.3.2
Model
Microscope is equipped with lenses to provide about 40X -
100X total magnification
Optical clarity is good
Microbiological Hood
Manufacturer
4.5
QC
QC
QC
4.4.1
4.4.2
Model
Hood is at least a class II biological safety cabinet
Hood is certified on an annual basis
Temperature Monitoring
4.5.1
4.5.2
4.5.3
4.5.4
Glass/mercury, dial thermometers or continuous recording
devices are used with appropriate equipment. Units are
graduated in no more than 0.5 °C increments. Mercury
columns are not separated
Calibration of glass/mercury thermometers is checked
annually and dial thermometers quarterly at the temperature
used against a reference NIST thermometer or one meeting
the requirements of NIST Monograph SP 250-23
Correction data are available for reference thermometers
Continuous recording devices are recalibrated annually
ApD-5
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Item to be evaluated
4.6
Evaluation
Incubator
Manufacturer Model
4.6.1 An internal temperature of 36.5 ± 1 °C is maintained
4.6.2 A temperature monitoring device is placed on a shelf near
area of use. The bulb or probe of the temperature monitor-
ing device is in liquid
QC
4.7
4.6.3 Temperature is recorded at least once per day for each
workday in use
Refrigerator
Manufacturer Model
4.7.1 An internal temperature of 1 ° to 5 °C is maintained
4.7.2 A temperature monitoring device is placed on a shelf near
area of use. The bulb or probe of the temperature monitor-
ing device is in liquid
QC
4.8
4.7.3 Temperature is recorded at least once per day for each
workday in use
Freezer, -20 °C
Manufacturer Model
4.8.1 An internal temperature of -20 ° ± 5 °C is maintained
4.8.2 A temperature monitoring device is placed on a shelf near
area of use.
QC
4.9
4.8.3 Temperature is recorded at least once per day for each
workday in use
Freezer, -70 °C
Manufacturer Model
4.9.1 An internal temperature of -70 ° ± 3 °C or lower is main-
tained
4.9.2 A temperature monitoring device is placed on a shelf near
area of use
ApD-6
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Item to be evaluated
QC
4.10
4.9.3 Temperature is recorded at least once per day for each
workday in use
Evaluation
Refrigerated Centrifuge
Manufacturer Model
4.10.1 Operates at a centrifugal force of at least 4,000 xg
4.10.2 Holds at 4°C during centrifugation run
4.10.3 Appropriate rotor holds 100 - 1000 ml bottles
QC
4.11
4.10.4 A log recording rotor serial number, run speed and time,
run temperature and operator's initials is kept for each
centrifugation run
Balance
Manufacturer Model
QC
QC
4.11.1 Balance is calibrated monthly
4.11.2 Correction data are available for S/S-1 calibration weights
4.11.3 An annual service contract or internal maintenance protocol
is maintained
4.12
Autoclave
Manufacturer Model
4.12.1 Unit is equipped with a temperature gauge with sensor on
exhaust
4.12.2 Unit depressurizes slowly so that media do not boil over
4.12.3 Unit's automatic timing mechanism is adequate
4.12.4 A service contract or internal maintenance protocol is
maintained
4.12.5 A maximum temperature-registering thermometer or heat-
sensitive tape is used with each cycle
QC
QC
4.13
4.12.6 Spore strips or ampoules are used on a monthly basis
4.12.7 Date, contents, sterilization time and temperature are re-
corded for each cycle
Hot Air Oven (if used)
Manufacturer Model
ApD-7
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Item to be evaluated
4.13.1 Hot air oven maintains temperature of 170 - 180°C for at
least 2 h
4.13.2 Bulb or probe of temperature monitoring device is placed
in sand during use. Thermometer graduated in no more
than 10°C increments
QC
4.14
4.13.3 Date, sterilization time and temperature are recorded for
each cycle
Pump
Manufacturer
Pump is self-priming
4.15
Polypropylene Container
Manufacturer/Source
Evaluation
Model
Model/Cat. No.
Container holds 40 L; contents can be mixed without spill-
ing
4.16
Positive Pressure Source (record for source used)
Compressed air
Compressed nitrogen
Laboratory air source
Manufacturer
Peristaltic pump
Manufacturer
4.17
Magnetic Stirrer
Manufacturer
4.18
Source for Reagent Grade Water
Type/Manufacturer
Model
Model
Model
Model/Cat. #
4.18.1 Still or deionization unit is maintained according to manu-
facturer's instructions
4.18.2 Reagent grade water is used to prepare all media and re-
agents
QC
4.18.3 The conductivity is tested with each use. Conductivity is
>0.5 megohms-cm at25°C
ApD-8
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Item to be evaluated
5. General Laboratory Practices
5.1 Analytical Media
5.1.1 General
5.1.1.1 Commercial media and chemicals are dated upon receipt.
Only analytical reagent or ACS grade chemicals are used
for preparation of media
5. 1 . 1 .2 Commercial dehydrated or liquid media are used for propa-
gation of tissue culture cells. Dehydrated media are pre-
pared and stored as recommended by manufacturers.
5.1.1.3 Commercial media and chemicals are discarded by man-
ufacturers' expiration dates. Laboratory prepared media are
discarded by the expiration dates indicated in the Virus
Monitoring Protocol
5. 1 . 1 .4 Each lot of medium is checked for sterility before use
QC 5.1.1.5 Lot numbers of commercial media and chemicals are re-
corded. Date of preparation, type of medium, lot number,
sterilization procedure, pH and technician's initials are
recorded for laboratory prepared media
5.1.2 Thiosulfate (2%)
Solutions are stored at or below room temperature and
discarded after six months
5.1.3 Hydrochloric acid
5.1.3.1 Solutions are prepared at least 24 h prior to use in sampling
or virus assays
5.1.3.2 Solutions are stored at or below room temperature and
discarded after six months
5.1.4 Sodium Hydroxide
5. 1 .4. 1 Solutions are prepared at least 24 h prior to use in virus
assays
5.1.4.2 Solutions are stored in polypropylene containers at room
temperature and discarded after 3 months
5.1.5 Beef Extract (1.5%)
5.1.5.1 Final pH is 9.5
Evaluation
ApD-9
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Item to be evaluated
5.1.5.2 Solution is stored at 4°C and discarded after one week or at
-20 °C and discarded after 18 months
Evaluation
5.1.6 Sodium Phosphate
5.1.6.1 Final pH is between 9.0 and 9.5
5.1 .6.2 Solutions are stored at or below room temperature and
discarded after six months
5.1.7 Washing Solution
5.1.7.1 Salt solution is cooled to room temperature before addition
of serum
5.1.7.2 Solutions are stored at 4°C and discarded after 3 months or
at -20 °C and discarded after 18 months
5.1.8 Chlorine
5.1.8.1 Final pH is between 6 and 7
5. 1 .8.2 Solutions are stored at or below room temperature and
discarded after one month
5.1.9 Iodine
Solutions are stored at room temperature and discarded
after six months
5.2 Sterilization and Disinfection
5.2.1 Autoclavable glassware, plasticware and equipment are
autoclaved at 121 °C for 1 h or, if appropriate, sterilized by
dry heat at 170°C for at least 1 h
5.2.2 Non-autoclavable supplies are disinfected with 0.1% chlo-
rine (pH 6-7) for 30 min or in a gas sterilizer according to
the manufacturer's recommendations
5.2.3 Contaminated materials are autoclaved at 121 °C for at
least 1 h
5.2.4 Adequate glassware washing facilities are available for re-
usable lab ware
5.2.5 Surfaces are disinfected before and after use and after spills
7. Quality Assurance
A written QA plan is followed and available for inspection
ApD-10
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SECTION II - ANALYST-SPECIFIC INFORMATION (To be filled out for each principal
analyst/analyst/technician seeking approval for ICR virus analysis):
Name of Analyst/Technician:
Item to be evaluated
Evaluation
6. Analytical Methodology
6.1 General
Only the virus analytical method dated July, 1995, is used for site
visit evaluation
6.2 QC Samples
A polypropylene container and pump are used to pump a negative
QC sample through a 1MDS filter in a standard sampling appara-
tus. All components of the system are sterile
6.3 Filter Elution
6.3.1 Residual water is blown out from the cartridge housing
before addition of beef extract
6.3.2 1MDS filters are slowly eluted with 1.5% beef extract
twice. The flow of beef extract is interrupted for 1 min
during each pass to enhance elution
6.3.3 An air filter is used with a positive pressure lab air source
6.4 Organic Flocculation
QC 6.4.1 The pH meter is standardized at pH 4 and 7
6.4.2 The pH electrode is disinfected before and after use
6.4.3 The pH of the eluate is adjusted slowly to 3.5 ± 0. 1 with 1
M HC1 with stirring at a speed sufficient to develop a vor-
tex
6.4.4 The eluate is stirred for 30 min after pH adjustment
6.4.5 The pH adjusted eluate is centrifuged at 2,500 xg for 15
min at 4 °C.
6.4.6 Supernatant from centrifuge run is properly discarded
6.4.7 Precipitate from centrifuge run is dissolved in 30 ml of
0.15 M sodium phosphate.
QC 6.4.8 The pH meter is standardized at pH 7.0 and 10.0
6.4.9 The pH electrode is disinfected before and after use
ApD-ll
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Name of Analyst/Technician:
Item to be evaluated
6.4.10 The pH of the dissolved precipitate is checked and read-
justed to 9.0-9.5, if necessary
6.4.11 The dissolved precipitate is centrifuged at 4,000-10,000 xg
for 10minat4°C
6.4.12 The supernatant from the 4,000-10,000 xg run is saved and
the precipitate properly discarded
6.4.13 The pH of the supernatant is adjusted to 7.0-7.5 with 1 M
HC1
6.4.14 The supernatant is treated to remove or reduce microbial
contamination. Sterilizing filters are pretreated before use
with beef extract
6.4.15 The final volume is recorded after treatment
6.4.16 The treated supernatant is divided into subsamples.
6.5
QC
Evaluation
Total Culturable Virus Assay
6.5.1 Passage 117 to 250 BGM cells from the U.S. EPA are
being cultured for ICR virus assays
6.5.2 Cultures are used 3-6 days after passage. Cultures are
washed prior to inoculation with serum free medium
6.5.3 At least 10 replicate cultures per subsample or subsample
dilution are inoculated with a proper inoculation volume
6.5.4 Inoculation volume does not exceed 0.04 ml/cm2
6.5.5 An adsorption period of 80-120 min is used. Adsorption
occurs at 22 to 3 6. 5 ± 1°C
6.5.6 Liquid maintenance medium is added and cultures are
incubated at 36.5 ± 1°C
6.5.7 A 2nd passage is performed using 10% of the medium
from the 1st passage. Samples positive in the 1st passage
are filtered prior to passage
6.5.8 Analyst demonstrates ability to perform MPN calculations
6.5.9 A positive and negative control is run with each sample
ApD-12
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DESCRIPTION OF CHECKLIST FOR LAB APPROVAL FOR VIRUS ANALYSIS
Note: Written records must be retained for five years for quality control items designated as
"QC".
1. Personnel
1.1 Principal Analyst/Supervisor
The principal analyst/supervisor is a qualified microbiologist with experience with environ-
mental virology. The principal analyst/supervisor oversees all analyses of samples for viruses.
1.1.1 Academic Training: Minimum of a bachelor's degree in the life sciences.
1.1.2 Job Training: Minimum of three years experience in cell culture and animal virus
analyses.
1.2 Analyst
The analyst performs at the bench level with minimal supervision and is involved in all aspects
of the analysis, including sample collection, filter extraction, sample processing and assay.
1.2.1 Academic Training: Minimum of two years of full time college with a major in
life science.
1.2.2 Job Training: Minimum of six months of full-time bench experience in cell
culture and animal virus analyses.
1.3 Technician
The technician extracts the filter and processes samples, but does not perform tissue culture
work.
1.3.1 Academic Training: No requirements.
1.3.2 Job Training: Three months experience in filter extraction of virus samples and
sample processing.
2. Laboratory Facilities
2.1 Laboratory facilities are temperature and humidity controlled. Laboratories are clean; a
pest control program is in place, if appropriate.
2.2 Work surfaces have adequate lighting (minimum of 100 foot-candles).
2.3 Laboratory bench tops have smooth, impervious surfaces.
ApD-13
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2.4 There is at least six to ten linear feet of usable bench space per analyst with a minimum of
36-38 inches of depth.
2.5 There is sufficient laboratory space for storage of media, glassware and equipment.
2.6 Filter extraction/sample processing is performed in a separate laboratory room from cell
culture and virus work. Cell culture and virus work are performed in separate rooms or in
separate microbiological hoods. A program is in place to ensure that no cross-contamination
occurs if the latter is used.
3. Laboratory Safety
3.1 The laboratory meets and follows laboratory biosafety level 2 guidelines.
3.2 Laboratories have limited access.
3.3 Lab coats are worn while working in laboratories.
3.4 Mouth pipetting is not allowed in the laboratory.
3.5 Food and drinks are not stored or consumed in the laboratory.
3.6 Biohazard signs identifying biohazards are placed on the laboratory access doors.
3.7 A written biosafety manual is followed and available for inspection.
3.8 Laboratory personnel have been given laboratory safety training.
3.9 The laboratory is in compliance with all applicable judicial ordinances and laws for virus
work and biological waste disposal.
4. Laboratory Equipment and Supplies
4.1 pH Meters
4.1.1 The accuracy and scale graduations of a laboratory pH meter are within ±0.1 pH
units. The accuracy and scale graduations of a portable pH meter for use with water
sampling are within ±0.2 pH units.
4.1.2 pH buffer aliquots are used only once.
4.1.3 Electrodes are maintained according to the manufacturer's recommendations.
ApD-14
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QC 4.1.4 Commercial buffer solution containers are dated upon receipt and when opened.
Solutions are discarded before the expiration date.
4.2 Light Microscope
4.2.1 The microscope is equipped with lenses to provide about 40X to 100X total
magnification.
4.2.2 Optical clarity is sufficient to accurately count cells in a hemocytometer.
4.3 Inverted Light Microscope
4.3.1 The microscope is equipped with lenses to provide about 40X to 100X total
magnification.
4.3.2 Optical clarity is sufficient to accurately demonstrate CPE.
4.4 Microbiological hood (if separate work areas are not available)
4.4.1 Hood is at least a class II biological safety cabinet.
QC 4.4.2 Hood is certified to be in proper operating condition on at least an annual basis.
4.5 Temperature Monitoring
4.5.1 Glass/mercury, dial thermometers or continuous recording devices are used to
monitor equipment. Units are graduated in 0.5°C increments or less. Mercury columns
in glass thermometers are not separated.
QC 4.5.2 The calibration at the temperature used of each glass/mercury thermometer is
checked annually against a reference National Institute of Standards and Technology
(formerly National Bureau of Standards) (NBS) thermometer or one that meets the
requirements of NIST Monograph SP 250-23. The calibration of each in-use dial ther-
mometer is checked quarterly.
QC 4.5.3 Correction data are available for all reference thermometers used for calibration.
QC 4.5.4 Continuous recording devices are recalibrated annually using the reference
thermometer described in QC 4.5.2.
4.6 Incubator
4.6.1 The incubator maintains an internal temperature of 36.5 ± 1 °C.
ApD-15
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4.6.2 A temperature monitoring device is placed on a shelf near area of use. The bulb
or probe of the temperature monitoring device is in liquid.
QC 4.6.3 The temperature is recorded at least once per day for each workday in use.
4.7 Refrigerator
4.7.1 The refrigerator maintains a temperature of 1 ° to 5 °C.
4.7.2 A calibrated temperature monitoring device is placed on a shelf near the area of
use. The thermometer bulb or probe is immersed in liquid.
QC 4.7.3 The temperature is recorded at least once per day for each workday in use.
4.8 Freezer,-20 °C
4.8.1 The freezer maintains a temperature of -20 ± 5 °C. The freezer may be a
compartment associated with 4.6.
4.8.2 A calibrated temperature monitoring device is placed on a shelf near the area of
use.
QC 4.8.3 The temperature is recorded at least once per day for each workday in use.
4.9 Freezer, -70 °C
4.9.1 The freezer maintains a temperature of -70 ± 3 °C or lower.
4.9.2 A calibrated temperature monitoring device is placed on a shelf near the area of
use.
QC 4.9.3 The temperature is recorded continuously during periods of use or at least once
per day for each workday in use.
4.10 Refrigerated Centrifuge
4.10.1 The centrifuge can be operated at a centrifugal force of at least 4,000 xg.
4.10.2 Centrifuge maintains an internal temperature of 4°C during run.
4.10.3 A rotor is available which is capable of 4,000 *g while holding centrifuge
bottles of 100- 1000ml.
ApD-16
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QC 4.10.4 A log recording rotor serial number, run speed, time of centrifugation, tempera-
ture of operation and operator is kept for each centrifuge run.
4.11 Balance
QC 4.11.1 The balance is calibrated monthly using Class S or S-l reference weights
(minimum of three traceable weights which bracket laboratory weighing needs) or
weights traceable to Class S or S-l weights.
QC 4.11.2 Correction data are available for the S or S-l calibration weights.
4.11.3 A service contract or internal maintenance protocol is established and records
are maintained.
4.12 Autoclave
4.12.1 The autoclave has a temperature gauge with a sensor on the exhaust, a pressure
gauge and an operational safety valve.
4.12.2 Autoclave depressurizes slowly to ensure that media do not boil over.
4.12.3 The autoclave's automatic timing mechanism is adequate. The autoclave
maintains sterilization temperature during the sterilizing cycle and completes an entire
liquid cycle within 45 min when a 12-15 min sterilization period is used.
4.12.4 A service contract or internal maintenance protocol is established and records
are maintained.
4.12.5 A maximum temperature-registering thermometer or heat-sensitive tape is used
with each autoclave cycle.
QC 4.12.6 Spore strips or ampules are used on a monthly basis.
QC 4.12.7 The date, contents, sterilization time and temperature is recorded for each
cycle.
4.13 Hot Air Oven (If used for sterilizing dry glassware.)
4.13.1 The oven maintains a stable sterilization temperature of 170 - 180°C for at
least two h.
4.13.2 A temperature monitoring device is used with the bulb or probe placed in sand
during use. The monitoring device is graduated in no more than 10°C increments.
ApD-17
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QC 4.13.3 The date, contents, sterilization time and temperature is recorded for each
cycle.
4.14 Pump
A self-priming pump is required for preparation of QC samples. It is recommended that the
pump be capable of pumping at a rate of 3 gal/min at 30 PSI.
4.15 Polypropylene Container
The container holds at least 40 L. The contents can be mixed without spilling or splashing.
4.16 Positive Pressure Source
An air or nitrogen source and pressure vessel or a peristaltic type pump is used for filter
elution.
4.17 Magnetic Stirrer
The magnetic stirrer is capable of maintaining a vortex during organic flocculation and pH
adjustments.
4.18 Source for Reagent Grade Water
4.18.1 Distillation and/or deionization units are maintained according to the manufac-
turer's instructions or water is purchased commercially.
4.18.2 Reagent grade water is used to prepare all media and reagents.
QC 4.18.3 The conductivity of the reagent grade water is tested with each use. The
conductivity is >0.5 megohms-cm at 25 °C.
5. General Laboratory Practices
5.1 Analytical Media
5.1.1 General
5.1.1.1 Commercial media and chemicals are dated upon receipt and when first
opened. Only analytical reagent or ACS grade chemicals are used for the prepara-
tion of media.
5.1.1.2 Use of commercial dehydrated or liquid media for propagation of tissue
culture cells are recommended due to concern about quality control. Dehydrated
media are prepared and stored as recommended by the manufacturers.
ApD-18
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5.1.1.3 Commercial media and chemicals are discarded by manufacturers'
expiration dates. Laboratory prepared media are discarded by the expiration dates
indicated in the Virus Monitoring Protocol.
5.1.1.4 Each lot of medium is checked for sterility before use as described in the
Virus Monitoring Protocol.
QC 5.1.1.5 The lot numbers of commercial media and chemicals are recorded. The
date of preparation, type of medium, lot number, sterilization procedure, pH and
technician's initials are recorded for media prepared in the laboratory.
5.1.2 Thiosulfate (2%)
5.1.2.1 A stock solution of 2% thiosulfate is prepared by dissolving 100 g of
Na2S2O3 in a total of 5000 ml of reagent grade water. The solution is autoclaved for
SOminat 121 °C.
5.1.2.2 2% thiosulfate is stored at or below room temperature for up to six months.
5.1.3 Hydrochloric acid (HC1)
5.1.3.1 Solutions of 0.1, 1 and 5 M HC1 are prepared by mixing 50, 100 or 50 ml
of concentrated HC1 with 4950, 900 or 50 ml of reagent grade water, respectively.
Solutions of HC1 are self-sterilizing and should be prepared at least 24 h prior to use.
5.1.3.2 Solutions of HC1 are stored at or below room temperature for up to six
months.
5.1.4 Sodium Hydroxide (NaOH)
5.1.4.1 Solutions of 1 M and 5 M NaOH are prepared by dissolving 4 or 20 g of
NaOH in a final volume of 100 ml of reagent grade water, respectively. Solutions
of NaOH are self-sterilizing and should be prepared at least 24 h prior to use.
5.1.4.2 Solutions of NaOH are stored in polypropylene containers at room
temperature for up to three months.
5.1.5 Beef Extract, 1.5%
5.1.5.1 Buffered 1.5% beef extract is prepared by dissolving 30 g of beef extract V
powder and 7.5 g of glycine (final glycine concentration = 0.05 M) in 1.9 L of
reagent grade water. The pH is adjusted to 9.5 with 1 or 5 M NaOH and the final
ApD-19
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volume is brought to 2 L with reagent grade water. The solution is autoclaved at
121 °C for 15 min.
5.1.5.2 Solutions of 1.5% beef extract are stored for one week at 4°C or for up to
18 months at-20°C.
5.1.6 Sodium Phosphate, 0.15 M
5.1.6.1 A solution of 0.15 M sodium phosphate is prepared by dissolving 40.2 g
of sodium phosphate (Na2HPO4 • 7H2O) in a final volume of 1000 ml of reagent
grade water. The pH is checked to ensure that it is between 9.0 - 9.5 and adjusted
with 1 M NaOH, if necessary. The solution is autoclaved at 121 °C for 15 min.
5.1.6.2 Solutions of 0.15 M sodium phosphate are stored at or below room
temperature for up to six months.
5.1.7 Washing Solution
5.1.7.1 Washing solution is prepared by dissolving 8.5 g of NaCl in a final volume
of 980 ml of reagent grade water. The solution is autoclaved at 121 °C for 15 min
and cooled to room temperature. 20 ml of bovine serum is added and the solution is
mixed thoroughly.
5.1.7.2 The wash solution is stored at 4°C for up to three months or at -20°C for
up to 18 months.
5.1.8 Chlorine, 0.1%
5.1.8.1 A solution of 0.1% chlorine (HOC1) is prepared by adding 19 ml of
household bleach to 900 ml of reagent grade water, adjusting the pH of the solution
to 6-7 with 1 M HC1 and bringing the final volume to 1 L with reagent grade water.
Solutions of 0.1% chlorine are self-sterilizing.
5.1.8.2 Solutions of 0.1% chlorine are stored at or below room temperature for up
to one month.
5.1.9 Iodine, 0.5%
5.1.9.1 A solution of 0.5% iodine is prepared by dissolving 5 g I2 in 1000 ml of
70% ethanol. Solutions of 0.5% iodine are self-sterilizing.
5.1.9.2 Solutions of 0.5% iodine are stored at room temperature for up to six
months.
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5.2 Sterilization and Disinfection
5.2.1 Autoclavable glassware, plasticware and equipment are sterilized by auto-
claving at 121 °C for 1 h or, if appropriate, by dry heat at 170°C for at least one h.
5.2.2 Non-autoclavable supplies are disinfected with 0.1% chlorine (pH 6-7) for 30
min or in a gas sterilizer according to the manufacturer's instructions.
5.2.3 Contaminated materials are sterilized by autoclaving at 121 °C for at least 1 h.
5.2.4 Adequate glassware washing facilities are available for washing re-usable
glassware.
5.2.5 All surfaces are disinfected with 0.5% iodine or 0.1% chlorine, pH 6-7 before
and after each use and after any spill or other contamination.
6. Analytical Methodology
6.1 General
Only the analytical methodology specified in the July, 1995, draft of the Virus Monitoring
Protocol for the Information Collection Rule is used for lab and analyst approval.
6.2 QC Samples
QC Each analyst and technician must prepare and process a negative QC sample during the
site visit (technicians will only be required to perform steps 6.3 to 6.4). A negative QC
sample is prepared by pumping 40 L of reagent grade water placed in a sterile polypro-
pylene container through a sterile standard sampling apparatus.
6.3 Filter Elution
6.3.1 Residual water is blown out from the cartridge housing.
6.3.2 Virus is eluted from the 1MDS filter by slowly passing 1000 ml of 1.5% beef
extract (pH 9.5) through the filter twice. The flow of beef extract is interrupted for 1
min during each pass to enhance elution.
6.3.3 An air filter is used with a positive pressure lab air source.
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6.4 Organic Flocculation
QC 6.4.1 The pH meter is standardized at pH 4 and 7.
6.4.2 The pH electrode is disinfected before and after use.
6.4.3 The pH of the eluate is adjusted slowly to 3.5 ± 0.1 with 1 M HC1 with stirring
at a speed sufficient to develop a vortex.
6.4.4 The eluate is stirred for 30 min after pH adjustment.
6.4.5 The pH adjusted eluate is centrifuged at 2,500 *g for 15 min at 4°C.
6.4.6 The supernatant is properly discarded after the centrifugation run.
6.4.7 The precipitate is dissolved in 30 ml of 0.15 M sodium phosphate.
QC 6.4.8 The pH meter is standardized at pH 7 and 10.
6.4.9 The pH electrode is disinfected before and after use.
6.4.10 The pH of the dissolved precipitate is readjusted to 9.0 - 9.5, if necessary.
6.4.11 The dissolved precipitate is centrifuged at 4,000 - 10,000 xg for 10 min at 4°C.
6.4.12 The supernatant is removed and saved after the centrifugation run. The pellet
is properly discarded.
6.4.13 The pH of the supernatant is adjusted to 7.0 - 7.5 with 1 M HC1.
6.4.14 The supernatant is treated to remove or reduce microbial contamination.
Sterilizing filters are pretreated before use with beef extract.
6.4.15 The final volume is recorded after treatment.
6.4.16 The treated supernatant is divided into subsamples.
6.5 Total Culturable Virus Assay
QC 6.5.1 Passage 117 to 250 BGM cell cultures obtained from the U.S. EPA are being
cultured for ICR virus assays.
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6.5.2 Cultures are used between three and six days after the most recent passage or
the laboratory has demonstrated that the culture time used is as sensitive as cultures at
three to six days. Cultures are washed prior to inoculation with serum-free medium.
6.5.3 At least ten replicate cultures per subsample or subsample dilution are
inoculated with an inoculation volume equal to l/20th the assay sample volume.
6.4.4 The inoculation volume does not exceed 0.04 ml/cm2.
6.5.5 Virus is allowed to adsorb onto cells for 80 - 120 min at room temperature or at
36.5 ±1°C.
6.5.6 Liquid maintenance medium is added and cultures are incubated at 36.5 ± 1 °C.
6.5.7 A 2nd passage is performed using 10% of the medium from the 1st passage.
Samples that were positive in the 1st passage are filtered before doing the 2nd passage.
6.5.8 The analyst demonstrates the ability to perform MPN calculations.
6.5.9 A positive and negative control is run with each sample.
7. Quality Assurance
The laboratory prepares and follows a written QA plan which is available for inspection during
the site visit.
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