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a)
Probability of Detection (POD).—
The proportion of positive analytical outcomes for a
1
qualitative method for a given matrix at a given analyte level or concentration. POD is
2
concentration dependent. Several POD measures can be calculated; POD
R
(reference method
3
POD), POD
C
(confirmed candidate method POD), POD
CP
(candidate method presumptive
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result POD) and POD
CC
(candidate method confirmation result POD).
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b)
Difference of Probabilities of Detection (dPOD).—
Difference of probabilities of detection is
6
the difference between any two POD values. If the confidence interval of a dPOD does not
7
contain zero, then the difference is statistically significant at the 5% level.
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Principle of the Method
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3M™ Molecular Detection Assay 2 -
Listeria
is used with the 3M™ Molecular Detection
12
System for the rapid and specific detection of
Listeria
species in enriched food and
13
environmental samples.
14
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The 3M Molecular Detection Assays use loop-mediated isothermal amplification to rapidly
16
amplify nucleic acid sequences with high specificity and sensitivity, combined with
17
bioluminescence to detect the amplification. Presumptive positive results are reported in real-
18
time while negative results are displayed after the assay is completed. Presumptive positive
19
results should be confirmed using the laboratory’s preferred method or as specified by local
20
regulations.
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General Information
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Listeria
is a small, Gram-positive rod that can be found in soil or carried by animals. Many
25
foods have been associated with
Listeria
contamination: uncooked meats, uncooked
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vegetables, cantaloupe, pasteurized and unpasteurized milk, and other dairy and processed
27
foods. [5] The resulting illness, listeriosis, from
Listeria monocytogenes
ingestion is rare but
28
can be fatal. The disease may appear as meningitis in adults and can affect unborn children
29
due to its ability to cross through the placenta.
Listeria
contamination often occurs post-
30
cooking, before packaging as
Listeria
can survive longer under adverse environmental
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conditions that can most other vegetative bacteria that present a concern for the food safety
32
industry. [6] Manufacturing facilities implement sanitation practices and regular surface
33
screening for the presence of
Listeria
on food contact surfaces to monitor their food
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production environments. The regular surface screening for non -
Listeria monocytogenes
35
species is used as an indicator to monitor for the risk of
Listeria monocytogenes
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contamination and is typically part of a food manufacturing facility’s Hazard Analysis
37
Critical Control Point (HACCP) plan. The 3M MDA 2 -
Listeria
was developed to provide
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rapid and specific detection of
Listeria
in enriched food samples and on food processing
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surfaces.
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Materials and Methods
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Test Kit Information
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a)
Kit Name.
—
Molecular Detection Assay 2 –
Listeria
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AOAC Research Institute
Expert Review Panel Use Only
OMAMAN-29 D/ PTM Validation Report 111501
OMA ERP - June 2016
ERP Use Only