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Document 2 of 2 – 3M Petrifilm Salmonella Express PTM Study Report
Table 30. Statistical Analysis (POD) of 3M Salmonella Petrifilm Method Confirmed vs. Reference Method
1
(Independent Laboratory Data)
2
Matrix
MPN
a
/25g
(or 100g
for egg)
N
b
3M Petrifilm SALX Method
Confirmed
Reference Method
dPOD
C
f
95% CI
g
X
c
POD
c
d
95% CI
X
c
POD
R
e
95% CI
Ground
Chicken
N/A
h
5
0
0.000
0.000-0.435
0
0.000
0.000-0.435
0.000
-0.435-
0.435
0.79
20
12
0.600
0.387-0.781
11
0.550
0.342-0.742
0.050
-0.237-
0.326
Pasteurized
Liquid Egg
N/A
h
5
0
0.000
0.000-0.435
0
0.000
0.000-0.435
0.000
-0.435-
0.435
0.80
20
7
0.350
0.181-0.567
8
0.400
0.219-0.313
-0.050
-0.322-
0.233
Stainless
Steel
N/A
h
5
0
0.000
0.000-0.435
0
0.000
0.000-0.435
0.000
-0.435-
0.435
N/A
h
20
6
0.300
0.145-0.519
7
0.350
0.181-0.567
-0.050
-0.317-
0.226
a
MPN = Most Probable Number is based on the POD of reference method test portions using the AOAC MPN calculator,
with 95% confidence interval
b
N = Number of test portions
c
x = Number of positive test portions
d
PODC = Confirmed candidate method positive outcomes divided by the total number of
trials
e
PODR = Confirmed reference method positive outcomes divided by the total number of
trials
f
dPODC = Difference between the candidate method and reference method POD values
g
95% CI = If the confidence interval of a dPOD does not contain zero, then the difference is statistically significant at the 5% level
h
N/A = Not applicable
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