AOAC ERP MICRO AUGUST 2018

OMAMAN-44 A: Collaborative Study Manuscript Expert Review Panel Use Only August 2018

Pre-collaborative and Collaborative Report Peel Plate EB

Table 11. Evaluation of Peel Plate EB assay perturbations

Bacterial Strain

Paired T- Test Probability of equivalence

High and Low Condition

Mean cfu/mL

Log Difference a

Assay Perturbation

SD

CV%

LCL b

UCL c

Serratia marcescens ATCC 13880 Citrobacter fruendii ATCC 8090 Serratia marcescens ATCC 13880 Citrobacter fruendii ATCC 8090 Hafnia alvei ATCC 51815 Enterobacter aerogenes ATCC 13048

41 36 31 32 44 60 48 65 21 22

5 7 5 8 7 9

13% 17% 21% 19% 15% 14% 20% 15% 14% 14% 10%

35°C 39°C 35°C 39°C

20%

-0.059

-0.130

0.012

Temperature

54%

0.046

-0.030

0.123

900µL

<0.1%

0.131

0.093

0.170

1100 µL

Pipet Volume

10

900µL

<0.1%

0.135

0.064

0.206

1100 µL 22 hours 50 hours 22 hours 50 hours

9 3 3

6%

0.014

0.007

0.022

Assay Time

100 101

10

16%

0.002

-0.006

0.014

9

9%

a Mean log cfu/mL difference between the low and high pairs n=10 pairs. b 95% Lower confidence limit for difference of means. c 95% Upper confidence limit for difference of means.

ERP Use Only

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