THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
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ETV Joint Verification Statement
TECHNOLOGY TYPE: IMMUNOASSAY TEST KITS
APPLICATION:
DETECTING ANTHRAX AND RICIN
TECHNOLOGY NAME: QTL Biosensor
COMPANY: QTL Biosystems, LLC
ADDRESS:
WEB SITE:
E-MAIL:
2778 Agua Fria Street PHONE 877-785-2461
Santa Fe, New Mexico 87507 FAX: 505-424-8679
www.qtlbio.com
qtlinfo@qtlbio.com
The U.S. Environmental Protection Agency (EPA) supports the Environmental Technology Verification (ETV)
Program to facilitate the deployment of innovative or improved environmental technologies through performance
verification and dissemination of information. The goal of the ETV Program is to further environmental protection
by accelerating the acceptance and use of improved and cost-effective technologies. ETV seeks to achieve this goal
by providing high-quality, peer-reviewed data on technology performance to those involved in the design,
distribution, financing, permitting, purchase, and use of environmental technologies. Information and ETV
documents are available at www.epa.gov/etv.
ETV works in partnership with recognized standards and testing organizations, with stakeholder groups (consisting
of buyers, vendor organizations, and permitters), and with individual technology developers. The program evaluates
the performance of innovative technologies by developing test plans that are responsive to the needs of
stakeholders, conducting field or laboratory tests (as appropriate), collecting and analyzing data, and preparing
peer-reviewed reports. All evaluations are conducted in accordance with rigorous quality assurance (QA) protocols
to ensure that data of known and adequate quality are generated and that the results are defensible.
The Advanced Monitoring Systems (AMS) Center, one of six technology areas under ETV, is operated by Battelle
in cooperation with EPA's National Exposure Research Laboratory. The AMS Center evaluated the performance of
immunoassay test kits used to detect anthrax and ricin in water. This verification statement provides a summary of
the test results for the QTL Biosystems Biosensor.
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VERIFICATION TEST DESCRIPTION
The verification test for the QTL Biosensor was conducted at Battelle between November 2005 and March 2006
according to procedures specified in the Test/QA Plan for Verification oflmmunoassay Test Kits for the following
parameters: contaminant presence/absence; false positive/false negative response to interferents, drinking water
(DW) matrix effects, and cross-reactivity; consistency; method detection limit; field portability; ease of use; and
sample throughput. The ability of the QTL Biosensor to detect various concentrations of anthrax and ricin was
evaluated by analyzing performance test (PT) and DW samples. PT samples included American Society for Testing
and Materials Type II deionized (DI) water fortified with the target contaminant, an interferent, both, or only a
cross-reactive species. Target analytes were added to DI water at lethal dose concentrations as well as at several
concentrations selected based on the vendor-stated limit of detection (LOD). The effect of interferents was
evaluated by analyzing two types of interferent solutions. The first type contained both humic and fulvic acids in DI
water, and the second type contained magnesium (Mg) and calcium (Ca) in DI water. Both types of interferent
solutions were prepared with and without the addition of the contaminants at a single concentration level (10 times
the vendor-stated LOD). In addition, specificity was evaluated by exposing the QTL Biosensor to Bacillus
thuringiensis, a potentially cross-reactive compound for anthrax, and lectin from soybean, a potentially cross-
reactive compound for ricin. PT samples were analyzed in triplicate (with the exception of samples used to
determine the method detection limit for which seven replicates were analyzed). DW samples were collected from
four water utilities that use a variety of treatment methods. DW samples, both unconcentrated and concentrated by a
factor of 400, were analyzed in triplicate both with and without the addition of anthrax and ricin at a concentration
of 10 times the vendor-stated LOD. In addition to the PT and DW samples analyzed, method blank (MB) samples
consisting of DI water were analyzed to confirm negative responses in the absence of any contaminant and to
ensure that no sources of contamination were introduced during the analysis procedures.
QA oversight of verification testing was provided by Battelle and EPA. Battelle QA staff conducted a technical
systems audit and a data quality audit of 10% of the test data. This verification statement, the full report on which it
is based, and the test/QA plan for this verification are all available at www.epa.gov/etv/centers/centerl.html.
TECHNOLOGY DESCRIPTION
The following description of QTL Biosensor was provided by the vendor and was not verified in this test.
The QTL Biosensor is a handheld device that is similar to standard immunomagnetic sandwich assays and is
capable of detecting anthrax spores and ricin toxins in samples. The sample is added to the QTL Biosensor
cartridge which contains sensing reagents. The sensing reagents are composed of two materials: a magnetic
component and a fluorescent component. Receptors for the biological agent(s) of interest are contained in both
sensing reagents. Upon mixing the sample with the reagents, the magnetic and fluorescent components form a
complex with the biological agent(s) for which they are specific. A magnetic field is then applied. This separates all
magnetic materials (including any complexes containing the biological agent) from the solution, which contains
excess fluorophore. A wash is performed to remove all excess reagents materials from the sample chamber. Then,
an excitation wavelength of light is exposed to the magnetic pellet comprised of the biological agent complexes,
and the resulting fluorescence indicates the presence of the biological agent.
The QTL Biosensor contains both positive and negative controls to ensure the validity of results and proper
functioning of the QTL Biosensor. Both liquid and solid samples can be analyzed using the QTL Biosensor. Results
are displayed as a millivolt (mV) and percent of full scale (%FS) reading. The QTL Biosensor also has red/green
warning lights that can be set to a pre-determined mV threshold reading to indicate a positive/negative response
where a green light indicates no toxin below the mV threshold, and a red light indicates the presence of a toxin
above the mV threshold.
The QTL Biosensor includes an integrated bar code reader (use is optional), and a starter kit comes with 20 test
cartridges. Test cartridges are shipped with a sample collector, bio-hazard bag, and a bar code label. The cartridge
is single-use, self contained, self sealing, and includes all necessary reagents. It is 1.9 inches wide by 1.7 inches
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high by 0.5 inch deep. The QTL Biosensor is 11 inches long by 10 inches wide by 5 inches high and weighs 6
pounds. Its battery life is 16 hours of continuous operation, and it has a recharge cycle of 2 to 4 hours.
The QTL Biosensor has a liquid crystal display screen with a four-button user interface. The bar code reader
captures the cartridge type and serial number. Date, time, location, user identification, and serial numbers
(Biosensor and cartridge) are stored with each result. There is on-board data storage for the last 100 samples and
results can be uploaded electronically to a laptop computer (not included with the QTL Biosensor). The QTL
Biosensor pricing starts at $11,500, and the price of each cartridge is $21.
VERIFICATION OF PERFORMANCE
The tables that follow summarize the performance of the QTL Biosensor in detecting anthrax and ricin,
respectively.
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Anthrax Summary Table
Parameter
Contaminant-only
PT samples
Interferent
PT samples
DW samples
Cross-reactivity
False positives
False negatives
Consistency
Method Detection
Limit
Other Performance
Factors
Sample Information
DI water
0.5 mg/L humic and fulvic
2.5 mg/L humic and fulvic
50 mg/L Ca and Mg
250 mg/L Ca and Mg
Unconcentrated CA
Concentrated CA
Unconcentrated FL
Concentrated FL
Unconcentrated NY
Concentrated NY
Unconcentrated OH
Concentrated OH
1 x 106 spores/mL
Bacillus thuringiensis
Anthrax Concentration
(spore/mL)
200 (lethal dose)
1 x io5 (vendor-stated
limit of detection)
5 x IO5
1 x IO6
5 x IO6
unspiked
unspiked
1 x IO6
1 x IO6
unspiked
Positive Results out
of 3 Replicates
0
1
3
o
J
3
0
0
o
J
3
3
o
3
2
o
3
1
2
0
2
3
3
3
3
2
3
2
3
3
3
2
3
0
False positive results occurred in Ca and Mg interferent samples as well as the
Unconcentrated water from CA, FL, and NY and all concentrated drinking
water samples.
False negative results occurred only in the Unconcentrated CA, FL, and OH
drinking water samples.
Results were consistent (i.e., produced positive or negative results without
variation among replicates) in 21 out of 29 sets of replicates or 72%.
The method detection limit was determined to be the concentration generating
a 65 mV response. It was between IxlO5 spores/mL (vendor-stated limit of
detection) and 5xl05 spores/mL.
Long term storage of the test cartridges should be at 2-8 °C, but cartridges may
be kept at room temperature for up to six months. Analysis software was user-
friendly. The QTL Biosensor uses electricity or rechargeable batteries and
includes a rugged carrying case. Test cartridges and detector were used inside
and outside a laboratory by trained operator as well as non-technically trained
operator; sample throughput was 12 samples per hour.
Shading indicates results for unspiked sample.
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Ricin Summary Table
Parameter
Contaminant-only PT
samples
Interferent
PT samples
DW samples
Cross-reactivity
False positives
False negatives
Consistency
Method Detection
Limit
Other Performance
Factors
Sample Information
DI water
0.5 mg/L humic and fulvic
2.5 mg/L humic and fulvic
50 mg/L Ca and Mg
250 mg/L Ca and Mg
Unconcentrated CA
Concentrated CA
Unconcentrated FL
Concentrated FL
Unconcentrated NY
Concentrated NY
Unconcentrated OH
Concentrated OH
0.5 mg/L
Lectin from soybean
Ricin Concentration
(mg/L)
0.05 (vendor-stated limit of
detection)
0.25
0.5
2.5
15 (lethal dose)
unspiked
unspiked
0.5
0.5
unspiked
Positive Results out
of 3 Replicates
0
3
3
3
3
0
0
0
0
0
0
1
1
0
0
0
0
3
3
3
1
3
3
3
3
3
3
3
3
0
False positive results occurred in the Unconcentrated and concentrated FL
drinking water samples.
False negative results occurred only in the 250 mg/L Ca and Mg interferent
sample.
Results were consistent (i.e., produced positive or negative results without
variation among replicates) in 26 out of 29 sets of replicates or 90%.
The method detection limit was determined to be the concentration generating a
76 mV response. It was between 0.05 mg/L (vendor stated limit of detection)
and 0.25 mg/L.
Long term storage of the test cartridges should be at 2-8 °C, but cartridges may
be kept at room temperature for up to six months. Analysis software was user-
friendly. The QTL Biosensor uses electricity or rechargeable batteries and
includes a rugged carrying case. Test cartridges and detector were used inside
and outside a laboratory by trained operator as well as non-technically trained
operator; sample throughput was 12 samples per hour.
Shading indicates results for unspiked sample.
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Original signed by Gregory A. Mack 10/26/2006 Original signed by Jonathan G. Herrmann 11/12/2006
Gregory A. Mack Date Jonathan G. Herrmann Date
Vice President Director
Energy, Transportation, and Environment Division National Homeland Security Research Center
Battelle U.S. Environmental Protection Agency
NOTICE: ETV verifications are based on an evaluation of technology performance under specific, predetermined
criteria and the appropriate quality assurance procedures. EPA and Battelle make no expressed or implied
warranties as to the performance of the technology and do not certify that a technology will always operate as
verified. The end user is solely responsible for complying with any and all applicable federal, state, and local
requirements. Mention of commercial product names does not imply endorsement.
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