MOST PROBABLE NUMBER (MPN)
CALCULATOR
Version 2.0
User and System Installation and
Administration Manual
Version 4.0
August 2013
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MPN Calculator User Manual
Acknowledgements
The EPA-MPN program was prepared by Avineon, Inc., 4825 Mark Center Drive, Suite
700, Alexandria, VA 22311-1846 under EPA Contract Number GS-35F-0018J, Task
Order Number 1517 and modified under subsequent task orders. This User and System
Installation and Administration Manual was prepared by Avineon, Inc. and modified by
the U.S. Environmental Protection Agency.
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TABLE OF CONTENTS
1.0 Introduction 1
2.0 Installation 2
2.1 Installation Requirements 2
2.2 Installation Problems 2
3.0 Default behavior configurations 2
3.1 Using the MPN Calculator for bacterial and viral MPN calculations 2
3.2 Limitations on MPN Calculator Usage 4
3.3 Solution Evaluation 4
3.4 Including Other Values to MPN Calculations 6
3.5 Exact Limit Calculation 7
3.6 Results Precision 8
3.7 Maximum Number of Iterations 9
4.0 Keyboard data entry mode 10
4.1 Standard Serial Dilutions 10
4.2 Other (Non-Standard) Dilutions 11
4.2.1 Constant Number of Tubes Per Dilution 12
4.2.2 Variable Number of Tubes Per Dilution 13
4.3 Saving Results 15
4.3.1 Save Results as a Text File 15
4.3.2 Save Results as an Excel File 16
4.3.3 Save Results as a Word File 17
5.0 file data entry mode 19
5.1 Input File Specifications 19
5.1.1 STANDARD Format Specifications 19
5.1.2 STANDARD Input File Example 20
5.1.3 SHORT/MAX Format Specifications 21
5.1.4 SHORT/MAX Input File Example 21
5.1.5 SHORT/MAX Input File Example 22
5.1.6 SHORT/MIX Input File Example 23
5.2 Output Specifications 23
5.3 Running with Input Files 24
5.4 Saving Results 26
5.4.1 Save Results as a Text File 26
6.0 View history 28
6.1 History Panel Discussion 28
6.2 Date and Time Formats 30
6.3 Search Examples 30
6.3.1 Search for Records Computed on a Specific Date 30
6.3.2 Search for Records Computed Between Dates 31
6.3.3 Search for 2-Fold Serial Dilution Records 31
6.4 Save Matched Records 32
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7.0 Records saving & database archiving 34
7.1 Archive Location 34
7.2 Archive Size 35
7.3 Auto-Save Records 36
8.0 References 37
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1.0 INTRODUCTION
Mr. Albert J. Klee (Risk Reduction Engineering Laboratory, United States Environmental
Protection Agency, Cincinnati, OH 45268, USA) developed and published a FORTRAN console
program to determine Most Probable Number (MPN) estimates in 1993 (see reference 8.3). The
program was developed for bacteriologists and named "mpn.exe." It computes the MPN value
estimate based upon a probability algorithm, the Spearman-Karber estimates, the Salama
correction for bias, the approximate confidence limits of Cornish & Fisher, and the exact
confidence limits of Loyer & Hamilton. Data is input using the keyboard or an input text file.
The program contained a series of default values based upon typical bacteriological analyses, but
allowed the user to change the defaults values. These included defaults for the Confidence Level
(95%), the Number of Dilutions (3), the Number of Tubes per Dilution (5), and the Size of the
Initial Volume (10 mL). Users can also toggle the default setting of "10-Fold Serial Dilutions" to
"Non-Standard Dilutions." For 10-fold dilutions, data is input as the number of positive tubes
per dilution level. For non-standard dilutions, users input both the number of positive tubes per
dilution level and the amount of sample represented at each dilution level.
Following EPA's publication of an Information Collection Rule in the mid 1990s requiring large
public drinking water utilities to monitor their water for contaminants, including viruses, Mr.
Klee developed a modified program for virologists, named "mpnv.exe " This version computes
only the MPN and the confidences limits (Cornish & Fisher, or Loyer & Hamilton). It contains
default values for the number of dilutions (1), the number of replicates per dilution (20), and the
inoculum volume (1 mL). Users can choose the default setting of "5-Fold Serial Dilutions" or
change the default to "Non-Standard Dilutions." For 5-fold dilutions, data is input as the number
of positive replicates per dilution level. For non-standard dilutions, users input both the number
of positive replicates per dilution level and the amount of sample represented at each dilution
level.
The MPN and MPNV programs were developed to run using the DOS operating system. They
run efficiently in MS-DOS command prompt window only under Windows operating systems
through Windows XP. Version 2.0 of the MPN Calculator was developed to run on XP and later
operating systems. There are two versions available: one for 32 bit (x86) based operating
systems and one for 64 bit systems. There are no versions available that run using the Mac
operating system.
The new MPN Calculator is an easy-to-use stand alone Windows application built by Avineon,
Inc. for the EPA. The calculator was built using Microsoft .NET (dot NET) version 3.5 SP1 (C#)
and Windows Presentation Foundation technologies. The new calculator not only combines the
main functionalities of both "mpn.exe" and "mpnv.exe", it allows users to save computed results
to 3 different file formats (TEXT, WORD and EXCEL) and to automatically record all results in
a local database for later retrieval. The algorithms for computing the Most Probable Numbers
(MPN) continue to be based on the Mr. Klee's "mpn.exe" FORTRAN code. The graphical user
interface (GUI) was redesigned (based on the old FORTRAN program's user interface).
The current version (2.0) of the EPA-MPN Calculator corrects a problem associated with the
calculation of MPN values associated with certain abnormal results (see section 3.2 for a
definition of abnormal results).
The following sections contain instructions on how to install, configure and use the new MPN
Calculator.
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2.0 INSTALLATION
2.1 Installation Requirements
Installation of the EPA-MPN program requires administrative rights. Users may need to have
the software installed by Information Technology personnel with these rights. The program
requires the prior installation of the latest versions of Microsoft .NET Framework and SQL
Server express appropriate for the installed operating system. Both of these can be downloaded
freely and installed by an individual with administrative rights by following the directions on the
Microsoft websites. The download site for .NET Framework is http://msdn.microsoft.com/en-
us/vstudio/aa496123.aspx and for the SQL Server Express is http://www.microsoft.com/en-
us/download/details.aspx?id=29062. After installing these files, download and save the x86
version of the EPA-MPN-Setup.msi installation file for 32 bit versions of Windows 7 by clicking
on the following link, http://www.epa.gov/nerlcwww/documents/x86-EPA-MPN-Setup.msi or
the version for 64 bit versions of Window 7 and Windows 8 by clicking of the following link,
http://www.epa.gov/nerlcwww/documents/64bit-EPA-MPN-Setup.msi. After the download is
complete, double click on the downloaded installation file and follow the file's installation
instructions.
2.2 Installation Problems
Please notify Dr. Shay Fout at fout.shay@epa.gov concerning problems with the installation or
use of the program or with any suggestions for its improvement. Note: some computers running
early Microsoft Windows version or non-Microsoft platforms may not run files with an "msi"
extension. Should this problem occur, an executable file and instructions for installing the MPN
program are available upon request.
3.0 DEFAULT BEHAVIOR CONFIGURATIONS
3.1 Using the MPN Calculator for bacterial and viral MPN calculations
The default opening screen is as shown:
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MPN Calculator User Manual
U.S. ENVIRONMENTAL PROTECTION AGENCY
An
*7 ol
LlSEZJ
I Most Probable Number (MPN) Calculator File Edit Tools Help
Data Entry Mode:
Keyboard
M
Dilution type:
Standard 5-Fold Serial
M
Approximation type;
@1
Cornish & Fisher Limits
Confidence level:
95%
0|
Standard Serial Dilutions
Number of Dilutions:
Number of Tubes per dilution: 5
Inoculum volume (ml): | |
Number of positive tubes in each dilution separated by commas:
Keyboard Results
Most Probable Number, MPN (per ml):
The MPN Calculator has added functionality over the older program, but some of the
terminology of the original programs is retained. In the screen shot above the term "Number of
Tubes per dilution" is equivalent to the term "Number of Replicates per Dilution" used by the
MPNV program. The term "Inoculum volume (ml)" is equivalent to the term "Size of the Initial
Volume" used in the MPN program. The program defaults as installed are 1 dilution (i.e., an
undiluted sample), 5 tubes per dilution (i.e., 5 replicates), an inoculum volume of 10 mL, and
standard 5-fold serial dilutions. The MPN and MPNV programs used standard 10-fold and
standard 5-fold dilutions, respectively. All other dilutions were non-standard and required the
user to input both the number of positive samples and their volumes. The MPN Calculator
allows the user to select standard 2-fold, 5-fold, or 10-fold dilution defaults. When these defaults
are selected, only the number of positive tubes (replicates) per dilution has to be entered.
Bacterial and viral MPN analyses often use different approaches for making and using dilutions.
These differences were taken into account when the original MPN and MPNV programs and the
new MPN Calculator were developed. Dilutions based upon the requirement to measure the
bacterial content in 100 mL of water are used when performing bacterial analysis of drinking
water,. Ten-fold dilutions typically are done either by directly assaying volumes of 10, 1.0, and
0.1 mL (or another dilution series depending on the likely bacterial content of the sample) or by
filtering each volume separately and then assaying the resulting filter. In each case, the ten-fold
lesser amounts represent serial 10-fold dilutions. To use the MPN Calculator to determine the
MPN of an analyses using 5 tubes each with 10, 1.0, and 0.1 mL volumes, the user would change
the Calculator's default settings to 3 dilutions and standard 10-fold dilutions. The default for the
number of tubes per dilution and the inoculum volume would remain at 5 and 10 mL,
respectively. After entering the positive tubes per dilution and clicking "RUN," the program will
show the MPN value per mL and the 95% Cornish and Fisher confidence limits. Note that the
MPN value is on a per mL basis. This value must be multiplied by 100 to obtain the MPN/100
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mL value. As an example, in the case of a 3 dilution assay (10, 1, 0.1 mL) using 5 tubes per
dilution and resulting in 5 (10 mL dilution), 1 (1 mL dilution), and 0 (0.1 mL dilution) positive
tubes per dilution, the MPN calculator gives a value of 0.33 MPN per mL with 95% confidence
values of 0.11 to 0.94 per mL or 33 (11-94) MPN per 100 mL. For this combination Table
9221. IV in Standard Methods (2005) gives a value of 30 (10-120) MPN per 100 mL. One of the
default settings in the MPN Calculator is the number of decimal places to use in MPN
calculations. For MPN values greater than 1, the default should be set to "0," because the
decimal values are not significant figures (see Section 1050 in Standard Methods for a discussion
of significant figures). Due to the wide confidence limits, even the second 3 in 33 is not
significant; therefore, Standard Methods rounds the result to 30.
Viral analyses are performed by preparing the dilutions and then using the same volume from
each dilution to inoculate the appropriate set of replicates. This approach is often also used with
bacterial analyses from surface waters and biosolids, but is necessary for virus assays because
the inoculum volume affects the adsorption efficiency of virus to cells in a tissue culture flask.
The use of different inoculum volumes would therefore result in an uncontrolled and unknown
variable. To prepare a 10-fold three dilution series for a virus assay, one might take 2 mL of an
undiluted sample and add it to 18 mL of a diluent to prepare a 1:10 dilution. After mixing, 2 mL
of the 1:10 dilution would be added to another 18 mL of the diluent to prepare a 1:100 dilution.
If an inoculum volume of 1 mL were used, then 1 mL of the undiluted sample would be
inoculated into each of 5 replicate tubes (e.g., tissue culture flasks), 1 mL of the 1:10 dilution
would be inoculated into each of 5 additional replicate tubes, and 1 mL of the 1:100 dilution
would also be inoculated into each of 5 additional replicates. The program defaults would be set
to 3 dilutions, 5 tubes per dilution, 1 mL inoculum volume, and standard 10-fold dilutions.
3.2 Limitations on MPN Calculator Usage
The MPN Calculator gives MPN values equivalent to those in Standard Methods (2005) for all
combinations given in Table 9221.IV. The calculator, however, uses an algorithm for the
calculation of confidence limits that results in similar, but not equivalent, values from those in
Standard Methods.
MPN data are not directly comparable unless consistent rules for usage are followed.
Calculations should be based upon the highest dilution at which all replicates are positive and the
next two to three higher dilutions. The number of dilutions used should always be consistent.
Experiments can result in abnormal results. Abnormal results include any values where the
number of positive replicates increase with dilution. The occurrence of abnormal results in more
than 1% of the data sets suggests technical issues or problems under which the statistics used to
develop an MPN may not apply; thus, MPN values calculated from abnormal results should be
not be used or used with caution only when there is a scientifically defensible reason for their
occurrence. Technical problems which may lead to abnormal results include 1) dilutions made
on clumped organisms at low concentrations, especially if the diluent results in the release of
organisms from clumps, and 2) the presence of inhibitory substances that are diluted out before
the target organism, e.g., when measuring virus concentration in environmental samples by PCR.
3.3 Solution Evaluation
There are two ways to compute MPNs: either manually (via the keyboard) or by loading dilution
data sets from a text file (also known as an input file).
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The new input files are the exact same as the input files used by the two previous FORTRAN
programs "mpn.exe", and "mpnv.exe". Since these FORTRAN programs were built for a
specific type of dilution (10-Fold Serial Dilution for "mpn.exe", and 5-Fold Serial Dilution for
"mpnv.exe"), they did not contain information about the type of dilution. For example, when
loading an input file through "mpnv.exe", the program automatically applies "5-Fold Serial
Dilution" for any standard dilution data sets encountered in the file.
Because the new input files are the same as the old and do not include the specific type of
dilution, the default for the dilution type must be set in the MPN Calculator before use. To
configure the default dilution type for file input:
Launch the MPN Calculator.
On the menu bar in the main window, click on "Tools" and then select "Preferences".
U.S. ENVIRONMENTAL PROTECTION AGENCY
Most Probable Number (MPN) Calculator Eiie Edit
view History
Standard Serial Dilutions
Number of Dilutions:
Number of Tubes per dilution:
Data Entry Mode:
Keyboard
Dilution type:
Inoculum volume I.ml):
Standard 5-Fold Serial
fvumaer ot positive tubes in each dilution seoaratec by commas:
Approxim atio n ty pe
Cornish & Fisher Limits
Keyboard Results
Most Probable Number, MPN [per ml):
Confidence eve I:
The "Preferences" window will appear.
Click on the "Dilution Type" tab
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OK
Preferences:
Dilution Type
When using file for data input, default the type of dilutions to:
ฉiTwo-Fold Serial Dilution
MPN
System Precision
Five-Fold Serial Dilution
Ten-Fold Serial Dilution
Calculation
Check the radio button corresponding to the desired dilution type and then click on the "OK"
button to save the setting and return to the main window (see screen capture below).
In the above example, "Two-Fold Serial Dilution" was checked; however, whichever dilution
type is selected, that dilution type will be applied to all standard dilution data sets found in any
input file.
Note:
To keep the default the same as the "mpn.exe" program, check the "Ten-Fold Serial
Dilution" radio button.
To keep the default the same as the "mpnv.exe" program, check the "Five-Fold Serial
Dilution" radio button.
3.4 Including Other Values to MPN Calculations
The "mpn.exe" program also computes confidence limits, Spearman-Karber estimates, and bias
corrections. The "mpnv.exe" program on the other hand only adds the confidence limits to the
MPN values.
The new MPN Calculator can be configured to compute any number of these values in addition
to the MPNs. To configure the application to add these values when computing the MPN, follow
the below steps:
Launch the MPN Calculator.
On the menu bar in the main window, click on "Tools", and then select "Preferences". The
"Preferences" window will appear.
Click on the "MPN" tab.
Check the desired checkbox(es), then click on the "OK" button to save the setting and return
to the main window (see screen capture below).
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MPN Calculator User Manual
U.S. environmental protection agency
Preferences:
Dilution Type MPN Syste
sm
Precision
Calculation
When computing the MPN, also include:
[V];Include confidence
limits.
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MPN Calculator User Manual
In the above example, "Include confidence limits", and "Bias correction" checkboxes were
checked. This setting instructs the program to include confidence limits and bias corrections
when computing MPN values.
Note:
To keep the default the same as the "mpn.exe" program, check all three checkboxes.
To keep the default the same as the "mpnv.exe" program, check the "Include confidence
limits" checkbox.
Note: when using input files to compute MPNs, checking or un-checking the "Include
confidence limits" has no effect on the end results. Instructions taken from the input files take
precedence.
3.5 Exact Limit Calculation
In the "mpn.exe" or "mpnv.exe" programs, the exact limits of Loyer & Hamilton can only be
computed if the total number of positive tubes combinations does not exceed 4,096. This number
represents the size of an array of double precision numbers that is used for every exact limit
calculation. For example, suppose there is a standard serial dilution with 4 dilutions and 8 tubes
per dilution. In this case, the total number of positive tubes combinations is 9*9*9*9 = 6561
(there are 9 possible results in each dilution). Even though both FORTRAN programs are
configured to compute the Loyer & Hamilton's limits, they both "ignore the setting" and the
approximate limits of Cornish & Fisher are calculated instead. This 4,096 limit was a threshold
set with the limitation of computing power in the early 1990s.
In the new MPN Calculator, the number of positive tubes combination is configurable. The
default value is set to 54,096. This value means that for each exact limit calculation, the program
may use an array of double precision numbers of the size up to 54,096 elements. To decrease or
increase this number:
Launch the MPN Calculator.
On the menu bar in the main window, click on "Tools", and then select "Preferences". The
"Preferences" window will appear.
Click on the "System" tab
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MPN Calculator User Manual
Type in the desired number in the textbox, then click on the "OK" button to save the setting
and return to the main window (see screen capture below).
U,S, ENVIRONMENTAL PROTECTION AGENCY
OK
15000
Dilution Type
MPN
Preferences:
When computing the exact limits of Loyer & Hamilton..
Default to Cornish & Fisher when S exceeds:
(S: number of all possible combinations of positive tubes)
System
Precision Calculation
In the above example, the threshold is set to 15,000. With this setting, the program will switch to
the approximate limits of Cornish & Fisher if, for a given series of dilutions, the total number of
positive tubes combinations exceeds 15,000, even if the exact limit of Loyer & Hamilton is
requested.
3.6 Results Precision
The new MPN calculator can be configured to truncate all computed results to a certain number
of digits after the decimal point: the default is 2. To change this number:
Launch the MPN Calculator
On the menu bar in the main window, click on "Tools", and then select "Preferences". The
"Preferences" window will appear.
Click on the "Precision" tab.
Type in the desired number in the textbox, then click on the "OK" button to save the setting
and return to the main window (see screen capture below).
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MPN Calculator User Manual
In the above example, the number of digits after the decimal point is set to 3.
3.7 Maximum Number of Iterations
In the "mpn.exe" or the "mpnv.exe" program, to be successful, a search for the approximate
limits must reach its target within 10 iterations. Beyond this number, both programs consider that
the algorithm does not converge, and the search for the approximate limits is considered to have
failed. In the same way, to be successful, a search for the exact limits must reach its target within
30 iterations. Beyond this threshold, the algorithm is not convergent. These threshold numbers
were hard-coded in both FORTRAN programs. In the new MPN calculator, these numbers are
configurable. To configure these numbers:
Launch the MPN Calculator.
On the menu bar in the main window, click on "Tools", and then select "Preferences". The
"Preferences" window will appear.
Click on the "Calculation" tab.
Type in the desired number in the textboxes, then click on the "OK" button to save the
setting and return to the main window (see screen capture below).
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U.S. ENVIRONMENTAL PROTECTION AGENCY
Preferences:
Calculation
Maximum iterations for Cornish & Fisher limits:
Maximum iterations for Lover & Hamilton limits:
OK
Dnution Type
MPN
System
Precision
In the above example, calculations of Cornish & Fisher limits are limited to 10 iterations (the
default value), and calculations of Loyer & Hamilton limits are limited to 30 iterations (the
default value). On most modern computers these defaults can be set to much higher values (e.g.,
50 and 100, respectively).
4.0 KEYBOARD DATA ENTRY MODE
Keyboard data entry mode allows computing one MPN value at a time only, by entering dilution
data manually (via keyboard). To compute multiple MPN values at a time, see the "File Data
Entry Mode" section. As in "mpn.exe" or "mpnv.exe", users can run the entered data with two
types of dilutions:
A standard serial dilution (which can be either "Standard 2-Fold", "Standard 5-Fold", or
"Standard 10-Fold"), or
A Non-Standard dilution.
4.1 Standard Serial Dilutions
To calculate MPNs using standard serial dilutions, follow the below steps:
Launch the new MPN Calculator.
In the main window, click on the "Data Entry Mode:" dropdown list and select the
"Keyboard" option.
Click on the "Dilution type:" dropdown list and select one of the three standard serial
dilution options:
o "Standard 2-Fold Serial"
o "Standard 5-Fold Serial"
o "Standard 10-Fold Serial".
Click on the "Approximation type:" dropdown list and select one of the two available
options: "Cornish & Fisher Limits" or "Loyer & Hamilton Limits".
Click on the "Confidence level:" dropdown list and select one of the four available
options:
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o "99%",
o "95%",
o "90%", or
o "50%".
In the "Standard Serial Dilutions" group box, type in:
o The number of dilutions in the "Number of Dilutions:" textbox.
o The number of tubes in the "Number of Tubes per dilution:" textbox.
o The initial inoculum volume (in ml) in the "Inoculum volume (ml):" textbox.
o The comma-separated list of observed positive tubes of the series of dilutions in
the "Number of positive tubes in each dilution separated by commas;" textbox.
Note: Press the "Tab" key or "Shift" + "Tab" keys to move forward or backward
respectively between textboxes
Click on the "RUN" button for results (see example screen below)
^D5r"^\ U.S. ENVIRONMENTAL PROTECTION AGENCY
^ Data Entry Mode;
J Most Probable Number (MPN) Calculator Eile Edit loois Help
| Keyboard
Dilution type:
| Standard 5-Fold Serial ~ |
Approximation type:
| Loyer St Hamilton Limits ~ |
Confidence level;
| 95%
Standard Serial Dilutions
Number of Dilutions:
Number of Tubes per dilution:
Inoculum volume (ml):
3
5
10
Number of positive tubes in each dilution separatee by commas:
5,3,0
Keyboard Results
Most Probable Number, MPN [per ml)f
SPEARMAN-KARBER Estimate:
MPN Corrected for Bias (Salama):
Lower 95% Confidence Limit (Loyer St Hamilton):
Upper 95% Confidence Limit (Loyer & Hamilton):
In the example screen above, the program computed the MPN value, the Spearman-Karber
estimate, the bias correction, and the Loyer & Hamilton Confidence Limits for a Standard 5-Fold
Serial dilution with:
o 3 as the number of dilutions in the series,
o 5 as the number of tubes per dilution,
o 10ml as the initial inoculum volume,
o And 5, 3, 0 as the number of observed positive tubes (5 observed positive tubes in
the first dilution, 3 in the second and 0 in the third).
(See section 2 for configuring the program to compute other values on top of the MPN).
4.2 Other (Non-Standard) Dilutions
With non-standard dilutions, the number of tubes per dilution can either be constant or variable.
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Constant Number of Tubes Per Dilution
Launch the new MPN Calculator.
In the main window, click on the "Data Entry Mode:" dropdown list and select the
"Keyboard" option.
Click on the "Dilution type:" dropdown list and select "Non-Standard".
Click on the "Approximation type:" dropdown list and select one of the two available
options: "Cornish & Fisher Limits" or "Loyer & Hamilton Limits".
Click on the "Confidence level:" dropdown list and select one of the four available
options:
o "99%",
o "95%",
o "90%", or
o "50%".
In the "Non-Standard Dilutions" group box, do the following:
o Type in the number of dilutions in the "Number of Dilutions:" textbox.
o Check the "Constant" radio button in the "Number of Tubes per dilution is:" radio
button list.
o Type in the number of tubes per dilution in the "Number of Tubes per dilution:"
textbox
o Type in the comma-separated list of inoculum volumes (in ml) in the "Inoculum
volumes for each dilution, separated by commas:" textbox.
o Type in the comma-separated list of observed positive tubes of the series of
dilutions in the "Number of positive tubes in each dilution separated by commas:"
textbox.
Note: Press the "Tab" key or "Shift" + "Tab" keys to move forward or backward
respectively between textboxes.
Note: The number of elements (separated by commas) in the last 2 textboxes
must match the number specified in the "Number of Dilutions:" textbox.
Click on the "RUN" button for results (see example screen below).
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U.S. ENVIRONMENTAL PROTECTION AGENCY
J&ZJ1
Most Probable Number (MPN) Calculator Eile Edit ioois Help
Data Entry Mode'
| Keyboard
Dilution type:
I Non-Standard
Approximation type;
| Cornish & Fisher Limits ~ |
Confidence levels
Non-Standard Dilutions
J^umber of Dilutionsi 3
Number of Tubes per dilution is: 'd'Constant Variable
Number of tubes per dilution: 5
Inoculum volumes for each dilution, separated by commas;
5, 1, 0,1
Number of positive tubes observed in each dilution, separated by commas:
5,4,2
Keyboard Results
Most Probable Number, MPN (per ml):
MPN Corrected for Bias (Thomas):
Lower 90% Confidence Limit (Cornish & Fisher}:
Upper 90% Confidence Limit (Cornish & Fisher):
2.21
1.88
0.93
5.02
In the example screen above, the program computed the MPN value, the bias correction, and the
Cornish & Fisher Confidence Limits for a Non-Standard dilution with constant number of tube
per dilution with:
o 3 as the number of dilutions.
o The number of tubes per dilution being constant and equal to 5.
o The inoculum volumes in each successive dilution being 5ml in the first dilution,
lml in the second dilution, and 0.1ml in the third,
o The numbers of observed positive tubes being 5 in the first dilution, 4 in the
second and 2 in the third.
Note: See section 2 for configuring the program to compute other values on top of the MPN.
4.2.2 Variable Number of Tubes Per Dilution
Launch the new MPN Calculator.
In the main window, click on the "Data Entry Mode:" dropdown list and select the
"Keyboard" option.
Click on the "Dilution type:" dropdown list and select "Non-Standard".
Click on the "Approximation type:" dropdown list and select one of the two available
options: "Cornish & Fisher Limits" or "Loyer & Hamilton Limits".
Click on the "Confidence level:" dropdown list and select one of the four available
options:
o "99%",
o "95%",
o "90%", or
o "50%"
In the "Non-Standard Dilutions" group box:
o Type in the number of dilutions in the "Number of Dilutions:" textbox.
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o
o
o
o Check the "Variable" radio button in the "Number of Tubes per dilution is:" radio
button list.
Type in the comma-separated list of number of tubes per dilution in the "Number
of Tubes for each dilution, separated by commas:" textbox.
Type in the comma-separated list of inoculum volumes (in ml) in the "Inoculum
volumes for each dilution, separated by commas:" textbox.
Type in the comma-separated list of observed positive tubes of the series of
dilutions in the "Number of positive tubes in each dilution separated by commas:"
textbox.
Note: Press the "Tab" key or "Shift" + "Tab" keys to move forward or backward
respectively between textboxes.
Note: The number of elements (separated by commas) in the last 3 textboxes
must match the number specified in the "Number of Dilutions:" textbox.
Click on the "RUN" button for results (see example screen below).
U.5, ENVIRONMENTAL PROTECTION AGENCY
J Most Probable Number (MPN) Calculator
Eile Edit Tools Jtielp
Z1 PflCft
Non-Standard Dilutions
Number of Dilutions:
Number of Tubes per dilution is
^ Data Entry Mode
Keybeard
O Variable
^cr stant
^ Dilution type;
| Non-Standard
Number or tubes for each dilution, separated by commas
6.4
Inoculum volumes for each dilution, s a pa rated by commas;
10.1.0.1
0 Approximation type:
| Cornish & Fisher Limits ~
Number ot positive tubes observed in each dilution, separated by commas
Confidence level:
| 90}
6,3,1
Keyboard Results
Most Probable Number, MPN (per ml):
MPN Corrected for Bias (Thomas):
Lower 90% Confidence Limit (Cornish & Fisher}
Upper 90% Confidence Limit (Cornish &. Fisher):
:
In the example screen above, the program computed the MPN value, the bias correction, and the
Cornish & Fisher Confidence Limits for a Non-Standard dilution with variable number of tubes
per dilution, with:
o 3 as the number of dilutions.
o The number of tubes per dilution being 6 in the first dilution, 4 in the second
dilution, and 2 in the third,
o The inoculum volumes in each successive dilution being 10ml in the first dilution,
1ml in the second dilution, and 0.1ml in the third,
o And the numbers of observed positive tubes being 6 in the first dilution, 3 in the
second and 1 in the third.
Note: See section 2 for configuring the program to compute other values on top of the MPN).
Page 14
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MPN Calculator User Manual
4.3 Saving Results
Results can be saved in one of the following formats: Excel spreadsheet, Word document, or
Text file.
4.3.1 Save Results as a Text File
Right-click on the result textbox.
In the pop-up context menu, select "Save As Text".
& U.S. ENVIRONMENTAL PROTECTION AGENCY
I Most Probable Number (MPN) Calculator File Edit Tools Help
2* pflctf
Non-Standard Dilutions
Number of Dilutio
Number of Tubes per dilution is:
Data Entry Mode
Keyboard
O Variable
Dilution type
Number ot tubes for each dilution, separated by commas:
6.4.2
Non-Standard
Inoculum volumes for each dilution, separated by commas;
10.1.0.1
Approximation type:
Cornish & Fisher Limits ~
Number of positive tubes observed in each dilution, separated by commas
6,3,1
Confidence leve
Keyboard Results
Most Probable Number, MPN (per ml}
MPN Corrected for Bias (Thomas)
Lower 90% Confidence Limit (Cornish 6. Fisher}:
Upper 90% Confidence Limit (Cornish & Fisher}:
Save As Text
Save As Excel
Save As Word
In the "Export Results To Text File " dialog box, navigate to the location where the results
will be saved, then type in the text file name.
Export Results To Text File
Save in: | TESTSCRIPT_DATA
Name Date modif... Type
Recent Places
Desktop
i
Serge Kaing
Computer
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Network
- *- a df
Size
No items match your search.
File name:
Save as type:
jtest Nonstandard
pTXTfM)
-
"31
Click on the "Save" button.
Page 15
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MPN Calculator User Manual
In the "MPN Calculator Message" dialog box, click on the "OK" button to finish.
Lju MPN Calculator Message
Exported successfully to D:\PUBLI
\TESTSCRIPT DATAXtestNonStandard.txt
.3.2 Save Results as an Excel File
Right-click on the result textbox.
In the pop-up context menu, select "Save As Excel".
^ U.S. ENVIRONMENTAL PROTECTION AGENCY
} Most Probable Number (MPN) Calculator File Edit Tools Help
Data Entry Mode;
[ Keyboard
Dilution typei
Non-Standard
Approximation type:
| Cornish &. Fisher Limits ~ |
Confidence level:
Non-Standard Dilutions
Number of Dilutions: 3
Number of Tubes per dilution is: Constant ง) Variable
Number of tubes for each dilution, separated by commas:
6,4,2
Inoculum volumes for each dilution, separated by commas:
10,1,0.1
Number of positive tubes observed in each dilution, separated by commas:
6,3,1
Keyboard Results
Most Probable Number, MPN [per ml}:
MPN Corrected for Bias (Thomas) :
Lower 90% Confidence Limit (Cornish &. Fisher):
Upper 90% Confidence Limit (Cornish &. Fisher):
1.8
1.41
0.56
r
Save As Text
Save As Excel
Save As Word
Page 16
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MPN Calculator User Manual
In the "Export Results To Excel File " dialog box, navigate to the location where the results
will be saved, then type in the text file name.
ฆst Export Results To Excel File
~EI3
Recent Places
Computer
Desktop
Network
Save in: ] , TESTSCRIPT_DATA
2] Name
Rle name: jtest Nonstandard
Save as type: | Excel (*jds)
Date mod if... Type
No items match your search.
Cancel
Save
Click on the "Save" button.
In the "MPN Calculator Message" dialog box, click on the "OK" button to finish.
M MPN Calculator Message
Exported successfully to D:\PUBLIC
1 "ESTSCRI FT DATA\testN o nSta n d a rd. x Is
.3.3 Save Results as a Word File
Right-click on any result textbox.
In the pop-up context menu, select "Save As Word"
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MPN Calculator User Manual
^ฐS^\ U.S. ENVIRONMENTAL PROTECTION AGENCY
I Most Probable Number (MPN) Calculator File Edit Tools Help
Data Entry Mode:
| Key beard
Dilution type:
Non-Standard
Approximation type:
I Cc-mish & Fisher Limits ~
Confidence level:
Non-Standard Dilutions
Number of Dilutions; 3
Number of Tubes per dilution is: Constant 0' Variable
Number of tubes for each dilution, separated by commas:
6,4,2
Inoculum volumes for each dilution, separated by commas;
10,1,0.1
Number of positive tubes observed in each dilution, separated by commas:
6,3,1
Keyboard Results
Most Probable Number, MPN (per ml);
MPN Corrected for Bias (Thomas):
Lower 90% Confidence Limit (Cornish & Fisher):
Upper 90% Confidence Limit (Cornish & Fisher):
1,8
1.41
ฐ. 56
3.ae
Save As Text
Save As Excel
Save As Word
In the "Export Results To Word File" dialog box, navigate to the location where the results
will be saved, then type in the text file name.
-fr Export Results To Word File
Save in: | TESTSCRIPT_DATA
Recent Places
Desktop
Serge Kaing
A-
Computer
5r'
Network
Name
Date modif... Type Size
No items match your search.
Rle name: |test Nonstandard
Save as type: |Word f.doc)
"3
Save
Cancel
Click on the "Save" button.
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MPN Calculator User Manual
In the "MPN Calculator Message" dialog box, click on the "OK" button to finish.
Ji MPN Calculator Message
Exported successfully to D:\PUBLIC
\TESTSCRI PT_DATA\test N o nSta n d a rd .doc.
5.0 FILE DATA ENTRY MODE
5.1 Input File Specifications
The MPN Calculator accepts 3 types of input file formats: "STANDARD", "SHORT/MAX",
and "SHORT/MIN".
5.1.1 STANDARD Format Specifications
Any line that starts with a semicolon is a COMMENT line (e.g. All blank lines are ignored.
When LINE is mentioned in the following discussion, it is meant to exclude BLANK or
COMMENT lines.
The first line must contain the string value "STANDARD".
The second line contains two pieces of information:
o One of the following three-character codes for the confidence level desired:
ฆ "99%",
ฆ "95%",
ฆ "90%", or
ฆ "50%".
-AND-
o One of the following two-character codes for the types of limits desired (Cornish &
Fisher or Loyer & Hamilton):
ฆ "CF", or
ฆ "LH"
The following lines in the file then contain information for the individual dilution data sets.
The first line of a dilution data set always contains the following two pieces of information
(separated by a comma or one or more spaces):
o The number of dilutions, and
o The number of tubes per dilution (e.g. either a number of the string value
"VARIABLE").
If standard dilutions (2-fold, 5-fold, 10-fold dilutions) are to be calculated for the data set,
then the inoculum volume must be entered on the 1st line following the number of tubes per
dilution.
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MPN Calculator User Manual
If standard dilutions (2-fold, 5-fold, 10-fold dilutions) are used, the second line contains the
number of positive tubes (separated by a comma or one or more spaces) observed in the
successive dilutions.
If non-standard dilutions are to be calculated for the data set, then the second and following
lines contain the data for each of the dilutions (one dilution data set to a line) (e.g. the
inoculum volume, the number of tubes per dilution if this was a variable, and the number of
positive tubes separated by a comma or one or more spaces).
5.1.2 STANDARD Input File Example
The following is a sample "STANDARD" MPN input file containing three dilution data sets.
Cornish & Fisher limits at the 95% confidence level are specified for all the sets.
STANDARD
95% CF
;BLUE RIDGE - TUESDAY RUN
3 10 1
10 6 1
;SPECIAL ANALYSIS FOR T.A. BROWN
3 8
1 10
.1 2
.01 0
The first dilution data set is a standard serial dilution with 3 dilutions, 10 tubes per dilution, and
an inoculum volume of 1ml. The number of observed positive tubes in each of the 3 dilutions is
10 for the first dilution, 6 for the second dilution and 1 for the third dilution.
Note: This is a standard serial dilution because an inoculum volume of 1ml is present in the first
line of the dilution data set. However, the dilution type (2-Fold, 5-Fold, 10-Fold) is unknown. To
see how this is determined by the program, see section 4.3.
The second dilution data set is a non-standard dilution with 3 10-fold dilutions and 8 tubes per
dilution. The number of observed positive tubes in each of the 3 dilutions is 10 for the first
dilution, 2 for the second dilution, and 0 for the third. It is a non-standard dilution because the
inoculum volume was not specified in the first line of the dilution data set. It is a 10-fold dilution
because the inoculum volumes decreased by a factor of 10.
The third dilution data set is also a non-standard dilution with 3 dilutions, but with a variable
number of tubes per dilution.
First dilution: inoculum volume = ,1ml, number of tubes per dilution = 10, and number of
observed positive tubes =10
Second dilution: inoculum volume = 0.03ml, number of tubes per dilution = 5, and
number of observed positive tubes = 4
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MPN Calculator User Manual
Third dilution: inoculum volume = 0.0045ml, number of tubes per dilution = 6, and
number of observed positive tubes = 0
5.1.3 SHORT/MAX Format Specifications
Any line that starts with a semicolon is a COMMENT line (e.g. All blank lines are ignored.
When LINE is mentioned in the following discussion, it is meant to exclude BLANK or
COMMENT lines.
The first line must contain the string value "SHORT/MAX".
The second line contains two pieces of information:
o One of the following three-character codes for the confidence level desired:
ฆ "99%",
ฆ "95%",
ฆ "90%", or
ฆ "50%"
-AND-
o One of the following two-character codes for the types of limits desired (Cornish &
Fisher or Loyer & Hamilton):
ฆ "CF", or
ฆ "LH"
The following lines in the file then contain information for the individual dilution data sets.
The first line of a dilution data set contains the following three pieces of information
(separated by a comma or one or more spaces):
o The number of dilutions,
o The number of tubes per dilution, and
o The initial inoculum volume in ml.
The following lines then contain the data for each of the dilutions, one dilution data set to a
line (e.g. the inoculum volume, the number of tubes per dilution if this was a variable and the
number of positive tubes separated by a comma or one or more spaces).
Note: The number of lines (e.g. the number of dilution data sets) must match the number of
dilutions specified in the first line of the dilution data sets.
5.1.4 SHORT/MAX Input File Example
If the number of dilutions, the number of tubes per dilution, and the initial inoculum volume are
constant over all dilution data sets, the input files can be simplified by specifying the
"SHORT/MAX" format. The following is a "SHORT/MAX" data file with 4 dilution data sets:
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MPN Calculator User Manual
SHORT/MAX
95% CF
3 5 1
5,3,0
5.4.2
5,0,0
5.4.3
The first dilution data set is a standard serial dilution with 3 dilutions, 5 tubes per dilution, and an
initial inoculum volume of 1ml. The observed numbers of positive tubes are 5 for the first
dilution, 3 for the second, 0 for the third dilution.
For the second dilution data set, the observed numbers of positive tubes are 5 for the first
dilution, 4 for the second, and 2 for the third dilution.
For the third dilution data set, the observed numbers of positive tubes are 5 for the first dilution,
0 for the second and third dilution.
For the fourth dilution data set, the observed numbers of positive tubes are 5 for the first dilution,
4 for the second, and 3 for the third dilution.
Note: "SHORT/MAX" notation is only for standard serial dilutions because the number of
dilutions, the number of tubes per dilution, and the initial inoculum volume must be present.
However, the dilution type (2-Fold, 5-Fold, 10-Fold) is unknown. To see how this is determined
by the program, see section 4.3.
5.1.5 SHORT/MAX Input File Example
Any line that starts with a semicolon is a COMMENT line. All blank lines are ignored and when
LINE is mentioned in the following discussion, it is meant to exclude BLANK or COMMENT
lines.
The first line must contain the string value "SHORT/MIN".
The second line contains two pieces of information:
o One of the following three-character codes for the confidence level desired:
ฆ "99%",
ฆ "95%",
ฆ "90%", or
ฆ "50%".
-AND-
o One of the following two-character codes for the types of limits desired (Cornish &
Fisher or Loyer & Hamilton):
ฆ "CF", or
ฆ "LH".
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MPN Calculator User Manual
The following lines in the file then contain information for the individual dilution data sets.
The first line of a dilution data set contains the following three pieces of information
(separated by a comma or one or more spaces):
o The number of dilutions,
o The number of tubes per dilution, and
o The initial inoculum volume in ml.
The following lines contain the data for each of the dilutions, one dilution data set to a line (e.g.
the inoculum volume, the number of tubes per dilution if this was a variable and the number of
positive tubes separated by a comma or one or more spaces).
Note: The number of lines (e.g. the number of dilution data sets) must match the number of
dilutions specified in the first line of the dilution data sets.
5.1.6 SHORT/MIN Input File Example
Contents of SHORT/MIN input files are exactly the same as those of SHORT/MAX input files
except at the very first line, where the string value "SHORT/MIN" replaces "SHORT/MAX":
below is an example.
SHORT/MIN
95% CF
3 5 1
5,3,0
5.4.2
5,0,0
5.4.3
5.2 Output Specifications
The "SHORT/MIN" input file format instructs the program to compute ONLY the MPN values
(regardless of any other settings) for each of the dilution data sets found in the input file.
The output of "STANDARD" and "SHORT/MAX" formats are identical. These types of input
file formats instruct the program to compute the MPN values for each of the dilution data sets
present in the input file, as with the "SHORT/MIN" format. Additionally, the program can
compute 3 other types of values depending on the settings in the "Preferences" window.
The Spearman-Karber estimate
The bias correction
The confidence limits (Cornish & Fisher, or Loyer & Hamilton).
To instruct the program to additionally compute one or all three of these values, follow the below
steps:
Launch the MPN Calculator.
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MPN Calculator User Manual
On the menu bar, click on "Tools", and then select "Preferences". The "Preferences"
window will appear.
On the "MPN" tab, check the desired value(s) to be included in the calculation.
U,S, ENVIRONMENTAL protection agency
OK
Dilution Type
Preferences:
When computing the MPIM. also include:
MPN
V Spearman-Karber estimate
171 Bias correction
System
Include confidence limits
Precision
Calculation
Click on the "OK" button to save your setting, and then close the "Preferences" window.
In the example above, all 3 values were checked. This setting instructs the program to compute
the Spearman-Karber estimate, the bias correction and the confidence limits in addition to the
MPN values for each of the dilution data sets found in any input file.
5.3 Running with Input Files
Input files do not contain information that tells the program the type of standard serial dilution
(2-Fold, 5Fold, or 10-Fold dilution) to apply to a dilution data set when needed, so the following
steps are needed to run the calculator with input files:
Make sure that your data file complies with the specifications mentioned above.
Launch the MPN Calculator.
On the menu bar, click on "Tools", and then select "Preferences". The "Preferences"
window will appear.
On the "Dilution Type" tab, check the desired dilution type: "Two-Fold Serial Dilution",
"Five-Fold Serial Dilution" or "Ten-Fold Serial Dilution".
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MPN Calculator User Manual
U.S. ENVIRONMENTAL PROTECTION AGENCY
Preferences:
Dilution Type MPN System Precision Calculation
When using file for data input, default the type of dilutions to:
0 iTwo-Fold Serial Dilution
Five-Fold Serial Dilution
Ten-Fold Serial Dilution
Cancel
Click on the "OK" button to save your setting, and then close the "Preferences" window.
In the example above, the "Two-Fold Serial Dilution" radio button was checked. This setting
instructs the program to apply 2-Fold Dilution Type to all standard dilution data sets found in
any input file.
In the main window, click on the "Data Entry Mode:" dropdown list and select the "File"
option.
In the "Input File" box of the main window, click on the "Browse" button.
In the "Open Dilution Data Set" dialog box, select the file to open.
Click the "Open" button
ฆ Open Dilution Data Set File
Recent Races
Desktop
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|M
Serge Kaing
Computer
Network
| ). TESTSCRIPT_DATA
Name Date modified
0 MIN_CF99.dat
0 MIN_LH50.dat
0 MIN_LH90.dat
0 MIN_LH95.dat
0 MIN_LH99.dat
0 STD_CF50.dat
[Sj STD_CF90.dat
0STD_CF95.dat
0 STD_CF99.dat
@ STD_LH50.dat
0 STD_LH90.dat
j _STD_LH95.dat
0 STD_LH99.dat
IS et M"
Type
Rle name:
Rles of type:
|STD_LH95.dal
| Data file f .dart)
"31
Open
In the "File Results" box, click on the "RUN" button to start computing MPN values.
The results are displayed in the "File Results" group box (see screen capture below).
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MPN Calculator User Manual
^/Vvu.s. ENVIRONMENTAL PROTECTION AGENCY
'A
I '.} Most Probable Number (MPN) Calculator EMe Edit loois Help
Data Entry Mode!
Dilution type;
| Standard 2-Fold Serial
Approximation type:
| Loyer St Hamilton Limits
Confidence level:
| 95%
Input File
Click on the Browse button be ow the select a data file:
D:\PUB LICNTE STSCRI PT_DATA\STD_LH 95.cat
3/3
MPN CF Lower CF Upper LH Lower LH Upper Bias
1 1.62 0,91 2,56 1.16 1.74 1.58
2 47.15 23.5 91,62 21.01 75.52 41.92
3 43.73 21.21 98 14.27 96.84 36.36
In the example result screen above, we can conclude that:
The file named "STD_LH95.dat" was selected as the input file
The program is configured to treat all standard serial dilution data sets contained
in the file as those of "Standard 2-Fold Serial" dilutions.
The input file instructs the program to compute exact limits of Loyer & Hamilton
at 95% confidence interval.
There are 3 dilution data sets in the input file.
5.4 Saving Results
Results from file inputs can also be saved into an Excel spreadsheet, a Word document, or Text
file.
5.4.1 Save Results as a Text File
The following describes the steps needed to save the results into a Text file.
Follow the steps described in section 4.3 to load an input file and compute MPNs and other
values.
In the "File Results" box, right-click on the result list.
Select "Save As Text".
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MPN Calculator User Manual
U.S. ENVIRONMENTAL PROTECTION AGENCY
I Most Probable Number (MPN) Calculator
File Edit Tools
P*ot^
,0 Data Entry Mode:
Dilution type:
| Standard 2-Fold Serial
^ Approximation type:
1 Loyer &. Hamilton Limits
Confidence level:
Input File
Click on the Browse button below the select a data file:
D: \PUBUC\TESTSCRIPT_DATA\STD_LH9 5.dat
File Results
3/3
MPN CF Lower CF Upper LH Lower LH Upper SK Estimate Bias
1 1.62 0.91 2.56 1.16 1.74 2.14 1.58
2 47.15 23.5 91.62 21.01 75.52 0 41.92
3 43.73 21.21
98 14.77 96.84
0 36.36
Save As Text
Save As Excel
Save As Word
In the "Export Results To Text File" dialog box, choose the desired location to save the file,
and then type in the text file name.
& Export Results To Text File
Save in: | . TESTSCRIPT.DATA
Desktop
B
Serge Kaing
Computer
C*
Network
Name Date modif... Type
[ ) testNonStandard.txt
Rle name: (test File Results
Save as type: |TXT f.txt)
- *ฆ B flฐ i"
1
Click on the "Save" button.
In the "MPN Calculator Message" dialog box, click the "OK" button to finish.
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MPN Calculator User Manual
MPN Calculator Message
Exported successfully to D:\PU3LIC
\TESTSCRIFT_DATA\testFileResults.txt.
NOTE:
To save results to a Word document, repeat the steps described above, but select "Save
As Word" in the popup context menu.
To save results to an Excel spreadsheet, repeat the steps described above, but select "Save
As Excel" in the popup context menu.
6.0 VIEW HISTORY
By default, all dilution data sets and their corresponding results are saved locally in a SQL
Server Compact Edition database. The following pieces of information are saved:
Dilution Data Set:
o Data entry mode: either Keyboard or Input File
o User name: login name of the user who entered the dilution data
o Dilution type: 2-Fold Serial, 5-Fold Serial, 10-Fold Serial, or Other (non-standard)
o Number of dilutions
o Number of tubes per dilution: a comma-separated list of integers
o Inoculum volumes: a comma-separated list of double precision numbers
o Observed positive tubes: a comma-separated list of integers
o Confidence Level: 99%, 95%, 90% or 50%
o Approximation type: approximate (Cornish & Fisher), or exact (Loyer & Hamilton)
o Comment (comment of a given dilution data set, if any, only from input file)
MPN Records
o MPN value: computed most probable number
o Lower X% Confidence limit (Cornish & Fisher, or Loyer & Hamilton)
o Upper X% Confidence Limit (Cornish & Fisher, or Loyer & Hamilton)
o Spearman-Karber estimate (if computed)
o Bias correction (if computed)
o Compute date
6.1 History Panel Discussion
To open the History panel, click on "Tools" on the menu bar, and then select "View History"
(see screen capture below).
Page 28
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MPN Calculator User Manual
U,5, environmental protection agency
History: Database: | EPA-MPN.sdf
Filter
User: skaing From date: Comment:
Entry mode: * | To date:
Dilution type: f AH T | Confidence level: f AH
Search Results
Search for MPN records
MPN CF Lower CF Upper LH Lower LH Upper SK Estimate Bias Conf. Level Dilution Type
The History panel has 3 main sections: "Database", "Search Results", and "Filter". The "Search
Results" section is used to display records matching the search criteria specified in the "Filter"
section. The "Database" section is used to specify which database the search operations should
operate on (the default is the current database). When the History panel loads, the "Database"
dropdown list is populated with all the database files that have been archived so far, including
the current database. The "Filter" section contains seven (7) fields. Each field can be used by
itself or can be combined with the others to form search criteria. The seven fields are as follows:
User: This field is used to look for records that were computed under a given login name
(the default is the current user's login name).
Entry mode: This field is used to look for records whose dilution data sets were entered
via the Keyboard or Input Files (the default behavior is All e.g. Keyboard AND Files).
Dilution type: This field is used to look for records with a certain type of dilution (the
default is All e.g. "2-Fold Serial" AND "5-Fold Serial" AND "10-Fold Serial" AND
"Other" Dilutions).
From date: This field is used to look for records that were computed/saved on a given
date/time. It also can be used to specify the lower bound of a date range (the default is
empty).
To date: This field is used to look for records that were computed/saved on a given
date/time. It can also be used to specify the upper bound of a date range (the default is
empty).
NOTE: see section 5.2 for details.
Confidence level: This field is used to look for records with confidence limits computed
with 99%, 95%, 90%, or and 50% confidence intervals (the default is All e.g. all 4
levels).
Comments: This field is used to look for records whose dilution data sets came from
input files and have some comments. Comments from input files are lines that start with a
semi-column. See section 4 for more details).
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MPN Calculator User Manual
6.2 Date and Time Formats
Accepted date formats are US date/time formats. The following formats are valid:
"MM/DD/YYY",
"MM/DD/YY",
"MM/DD/YY HH:MM AM",
"MM/DD/YYYY HH:MM PM".
If ONLY ONE of the "From date:" or "To date:" fields has a valid date/time value, then
If the date/time value does not have a time component then the program will search
for the entire 24 hour range of the specified date.
If the date/time value does have a time component, then the program will search from
the specified time until the end of the specified date (e.g. 11:59:59 PM).
If the "From date:" date is later then the "To date:" date, the user is notified of the incoherent
date/time range.
6.3 Search Examples
The search criteria and results described below are specific to the desktop on which the MPN
Calculator is installed. Modify the search criteria accordingly.
Launch the MPN Calculator.
On the menu bar, click on "Tools", and then select "View History". The "History"
window will appear.
6.3.1 Search for Records Computed on a Specific Date
rr
,S. ENVIRONMENTAL PROTECTION AGENCY
History:
Filter
User:
Entry mode: [^
Dilution type: fAjP
Database:
EPA-MPN.sdf
skaing From date:
10/27/09 11 AM Comment:
T To date:
T Confidence level: A"
Search for MPN records
Search Results
MPN
CF Lower CF Upper
LH Lower LH Upper
SK Estimate
Bias
Conf. Level Dilution Type
1
1.62
0.72
2.91
0.83
2.3
2.14
1.58
99%
2-Fold
2
47.15
18.27
123.4
16.83
100.8
0
41.92
99%
Other
3
43.73
16.52
160.09
11.53
124.36
0
36.36
99%
Other
4
1.62
1.36
1.93
1.39
1.63
2.14
1.58
50%
2-Fold
5
47.15
38.55
60.1
36.11
47.55
0
41.92
50%
Other
6
43.73
35.71
57.41
23.39
58.27
0
36.36
50%
Other
In the "From date:" textbox, type in a date time value. In the example screen above, the
date entered is October 27th 2009, at 11 AM.
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MPN Calculator User Manual
Click on the "Search for MPN records" button.
In the example screen above, the "Search Results" section shows that there are 6 records that
were computed between 11 AM and Midnight on October 27th 2009, under the login name
"skaing".
6.3.2 Search for Records Computed Between Dates
This section narrows the search criteria by a date range.
In the "To date:" textbox, type in "10/27/09 12 PM".
Click on the "Search for MPN records" button.
C U.S. ENVIRONMENTAL PROTECTION AGENCY
History:
Filter
User:
Entry mode:
Dilution type:
Search Results
E^A-MPN.sdf
skaing From date:
All
T To date:
10/27/09 11 AM Comment:
10/27/09 12 PM
All
T Confidence level: A"
Search for MPN records
MPN CF Lower CF Upper LH Lower LH Upper SK Estimate Bias Conf. Level Dilution Type
1 1.62 0.72 2.91 0.83 2.3 2.14 1.58 99% 2-Fold
2 47.15 18.27 123.4 16.83 100.8 0 41.92 99% Other
3 43.73 16.52 160.09 11.53 124.36 0 36.36 99% Other
In the example screen above, the "Search Results" panel shows that there are 3 records that
were computed between 11 AM and 12 PM on October 27th 2009, under the login name
"skaing".
Next: let's narrow down the search criteria with a specific dilution type.
6.3.3 Search for 2-Fold Serial Dilution Records
Click on the "Dilution type:" dropdown list and select "Std 2-Fold Serial".
Click on the "Search for MPN records" button.
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rr
s, environmental protection agency
History:
Filter
User:
Entry mode:
Database:
EPA-MPN.sdf
All
skaing From date:
T To date:
10/27/09 11 AM Comment:
10/27/09 12 PM
Dilution type: [5td 2-Fold Seri ~ Confidence level: |
Search Results
Search for MPN records
MPN CF Lower CF Upper LH Lower LH Upper SK Estimate Bias Conf. Level Dilution Type
1 1.62 0.72 2.91 0.83 2.3 2.14 1.58 99% 2-Fold
In the example screen above, the "Search Results" panel shows that there is only one record that
was computed between 11 AM and 12 PM on October 27th 2009, under the login name "skaing"
and with a standard 2-fold serial dilution.
6.4 Save Matched Records
Matched records can be saved as a Text file, a Word document or an Excel spreadsheet.
In the "Search Results" panel, select the items to save (press and hold down the "Ctrl" key to
select multiple items).
Right-click on a selected item.
In the popup context menu, select "Save As Text", "Save As Word", or "Save As Excel".
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U.S. ENVIRONMENTAL protection agency
History:
Filter
Users
Entry mode: | ^"
Dilution type:
Search Results
All
Database: EPA-MPN.sdf
skaing From date:
Comment:
T To date:
T Confidence level: rฎ1"
Search for MPN records
MPN CF Lower CF Upper LH Lower LH Upper SK Estimate Bias Conf. Level Dilution Type
10-Fold
Other
Other
10-Fold
Other
Other
10-Fold
10-Fold
10-Fold
4.35
47.15
43.73
4.35
47.15
43.73
4.35
74.23
2.97
2.05
23.5
21.21
3.53
38.55
35.71
0
0
0
9.22
91.62
98
5,65
60.1
57.41
0
4.26
21.01
14.27
0
0
0
4.36
75.52
96.34
0
0
0
12.59
0
0
12.59
0
0
Save As Text
Save As Excel
3.7
41.92
36.36
3.7
41.92
36.36
0
0
0
Save As Word
95%
95%
95%
50%
50%
50%
99%
99%
99%
In the example screen above, 3 MPN were selected and saved as a text file.
In the popup dialog box, choose the location to save the file to, and then type in the file
name.
: Save Selected Items To Text File
Save in: I .. TESTSCRIPT DATA
Recent Places
Desktop
G
Serge Kaing
A1
Computer
Network
Name Date modif.., Type
F'"1 te stArc h i ve Re s u Its. bet
[_JtestFileResults.txt
testNonStandard.txt
3 ซ- B a !
Size
File name:
Save as type:
| testArchi1veR esults2j txt
TXT r.tKt)
~3
Click on the "Save" button.
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MPN Calculator Message
Exported successfully to D:\PUBLIC
\TE5TSCRIPT_DATA\testArchiveResults2.txt.
In the popup dialog box, click on "OK" to finish.
7.0 RECORDS SAVING & DATABASE ARCHIVING
The new MPN Calculator, by default, automatically saves all computed results and the
corresponding input dilution data into a local Microsoft SQL Server Compact Edition (MSSQL
CE) v3.5 database file. This default behavior can be turned off by setting the value of the
"AutoSaveRecords" flag to the Boolean "False" in the application's configuration file. See
further in this section the steps for locating and editing the configuration file. Since all MSSQL
CE v3.5 database files are limited to a maximum size of 4GB, the Calculator also has a
mechanism that automatically archives the current database file into a configurable location (the
"ArchiveLocation") once it reaches a certain threshold (the "ArchiveSize").
The following sections describe how to configure the value of this threshold, the archive
location, and how to switch on/off the automatic records saving feature. These 3 values are set in
the application's configuration file named "EPA-MPN.exe.config", which is located in the
application's installation folder and can be edited with any text editor.
7.1 Archive Location
The MPN Calculator automatically archives its database file in the ARCHIVE folder under the
application's installation directory. To change this location, follow the below steps:
Exit the MPN Calculator.
With NOTEPAD.exe, open the file named "EPA-MPN.exe.config" in the application's
installation folder.
Locate the xml tag named "". This tag should be located at the end of
the file (see screen capture below).
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_j EPA-MPN.exe.config - Notepad
File Edit Format View Help
a -ฃ3-
Arcm veLocati on serianzeAs =
.\ARCHlVE
True
' should read:
. ARCHIVE.
The ".\ARCHIVE" represents the default location. This value means that the application will
automatically archive its database file in the "ARCHIVE" folder, in the application's installation
directory.
Change the value between the "" and "" tags to the desired location (e.g. the
value "D:\DATA\MPN-ARCHIVE").
Save the changes.
Exit NOTEPAD.exe to finish.
7.2 Archive Size
The MPN Calculator automatically starts the archiving process once its database file reaches a
certain threshold defined in the application's configuration file: the default value is
2,000,000,000 bytes, i.e. 2 GB. To change this value,
Exit the MPN Calculator.
With NOTEPAD.exe, open the file named "EPA-MPN.exe.config" in the application's
installation folder.
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Locate the xml tag named "". This tag should be located at the end of
the file (see screen capture below).
J EPA-MPN.exe,config - Notepad | <=. H B 11-^1
File Edit Format View Help
csettinq name="ArcniveLocation" serializeAs="string">
.\ARCHlVE
True
>
2QQQQQQQQQ
Within the "" and "" tags, locate the ""
tag named "ArchiveSize" i.e. the line that reads: .
If this is the first time that the application's configuration file is being edited, then the line
below '' should read:
< value >2000000000.
The value 2,000,000,000 represents the default threshold value in number of bytes. This means
that once the application's database file reaches 2GB, the archiving process starts. At the end of
this process the application's database file will return to its starting size (of about 200KB) and a
new archived database file of about 2GB will be created in the archive location defined in 6.1
Archive Location.
Change the value between the "" and "" tags to the desired value (e.g. the
value "5000000" for 5MB).
Save the changes.
Exit NOTEPAD.exe to finish.
7.3 Auto-Save Records
By default, the MPN Calculator automatically saves all computed results and associated dilution
data sets in its database file. The ArchiveLocation (see section 6.1) and the ArchiveSize (see
section 6.2) do not have any impact on the application's behavior if the automatic records saving
feature is turned off because the application's database file will not be growing. To turn this
feature off, follow the below steps:
Exit the MPN Calculator.
With NOTEPAD.exe, open the file named "EPA-MPN.exe.config" in the application's
installation folder.
Locate the xml tag named "". This tag should be located at the end of
the file (see screen capture below).
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EPA-MPN.exe.config - Notepad
File Edit Format View Help
csetting name="ArcniveLocation" serializeAs="string">
.\ARCHlVE
>
csetting name= AutoSaveRecords serianzeAs= strin
luH
True< ilu
2GGGGGGGGG
Within the "" and "" tags, locate the ""
tag named "AutoSaveRecords" i.e. the line that reads: .
If this is the first time that the application's configuration file is being edited, then the line
below '' should read:
Triie< value>.
Change the value between the "" and "" tags to the "False".
Save the changes.
Exit NOTEPAD.exe to finish.
8.0 REFERENCES
8.1 Cornish, E.A., and Fisher, R.A. 1937. Moments and cumulants in the specification of
distributions. Rev. Int. Statist. Inst. 5, 307-320.
8.2 Hamilton, M.A., Russo, R.C., and Thurston, T.V. 1977. Trimmed Spearman-Karber
method for estimating medium lethal concentrations in toxicity bioassays. Environ. Sci. Technol.
11, 714.
8.3 Klee, A.J. 1993. A computer program for the determination of most probable number and
its confidence limits. J. Microbiol. Methods. 18, 91-98.
8.4 Loyer, M.W., and Hamilton, M.A. 1984. Interval estimation of the density of organisms
using a serial-dilution experiment. Biometrics 40, 907-916.
8.5 Salama, I. A., Koch, G.G., and Tolley, H.D. 1978. On the estimation of the most probable
number in a serial dilution technique. Commun. Stat. Theor. Methodol. A7, 1267-1281.
8.6 Standard Methods for the Examination of Water and Wastewater, 21st Edition. 2005.
American Public Health Association.
8.7 Swaroop, S. 1951. The range of variation of the most probable number of organisms
estimated by the dilution method. Ind. Jour. Med. Res. 39, 107-134.
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8.8 Thomas, H.A. 1955. Statistical analysis of coliform data. Sewage Industr. Wastes 45,
212-222.
8.9 Wilde, D.J. 1964. Optimum Seeking Methods. Prentice-Hall Inc., Englewood Cliffs, NJ.
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