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Table 10. BAX® System Presumptive vs. Confirmed Results – Dairy Products

95% CI f

BAX® Presumptive

BAX® Confirmed

dPOD CPe

Test Portions

MPN a

Sample Type

Media

X b POD CP c

95% CI f

X b POD CC d

95% CI f

Control

5

0

0

(0, 0.43)

0

0

(0, 0.43)

0 0 0 0 0 0 0 0 0 0 0 0

(-0.45, 0.45) (-0.14, 0.14) (-0.45, 0.45) (-0.45, 0.45) (-0.14, 0.14) (-0.45, 0.45) (-0.45, 0.45) (-0.14, 0.14) (-0.45, 0.45) (-0.45, 0.45) (-0.14, 0.14)

Brilliant Green Water / BHI

Nonfat dry milk (25 g)

1.2 (0.79, 1.8) 9.4 (5.7, 16)

20

11

0.55

(0.34, 0.74) 11

0.55

(0.34, 0.74) (0.57, 1.0)

5 5

5 0 9 3 0 6 4 0 6 5

1.0

(0.57, 1.0)

5 0 9 3 0 6 4 0 6 5

1.0

Control

0

(0, 0.43)

0

(0, 0.43)

Ice cream (25 g)

LB

0.31 (0.17, 0.49)

20

0.45 0.60

(0.26, 0.66) (0.23, 0.88)

0.45 0.60

(0.26, 0.66) (0.23, 0.88)

1.8 (1.1, 2.7)

5 5

Control

0

(0, 0.43)

0

(0, 0.43)

Ice cream (25 g)

BPW

0.31 (0.17, 0.49)

20

0.30 0.80

(0.15, 0.52) (0.38, 1.0)

0.30 0.80

(0.15, 0.52) (0.38, 1.0)

1.8 (1.1, 2.7)

5 5

Control

0

(0, 0.43)

0

(0, 0.43)

Brilliant Green Water

Ice cream (25 g)

0.31 (0.17, 0.49)

20

0.3 1.0

(0.15, 0.52) (0.57, 1.0)

0.3 1.0

(0.15, 0.52) (0.57, 1.0)

1.8 (1.1, 2.7) (-0.45, 0.45) a MPN = Most Probable Number based on the POD of reference method test portions using the AOAC MPN calculator (with 95% confidence interval) 5

2 3 4 5 6 7 8 9

b X = Number of positive test portions

c POD CP = Candidate method presumptive positive outcomes divided by the total number of trials d POD CC = Candidate method confirmed positive outcomes divided by the total number of trials

e dPOD CP = Difference between the candidate method presumptive result and candidate method confirmed result POD values f 95% CI = If the confidence interval of a dPOD does not contain zero, then the difference is statistically significant at the 5% level

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