AOAC 2019 First Action Methods

Table 2019.02A. Collaborative Study Results of MC-Media Pad ® RAC vs. USDA MLG 3.02

Difference of Means d 95% LCL, UCL

Difference of Means b,c

MC-Media Pad ® RAC

USDA MLG 3.02

Mean Log 10 CFU/g

Mean Log 10 CFU/g

Matrix

Lot

N a

s R

Lot

N

s R

s r

s r

a

Raw Ground Pork (24 Hours) Raw Ground Pork (48 Hours)

Low

9 3.438 0.08 0.12 9 4.768 0.07 0.14

Low

9 9

3.423 0.16 4.754 0.09

0.18 0.16

0.015 0.014

-0.038, 0.068 -0.013, 0.042

Medium

Medium

High

9 5.313 0.12 0.17

High

9

5.322 0.08

0.16

-0.008

-0.054, 0.037

Low

9 3.465 0.09 0.13 9 4.782 0.08 0.14

Low

9 9

3.423 0.16 4.754 0.09

0.18 0.16

0.042 0.029

-0.018, 0.101 0.005, 0.052

Medium

Medium

High

9 5.354 0.11 0.15

High

9

5.322 0.08

0.16

0.032

-0.001, 0.066

a Number of laboratories that reported complete results. b Mean Log 10 Candidate method – Mean Log 10 Reference method c A 95% confidence interval for the true mean difference within +0.5 indicates equivalence of the two methods d 95% Lower and Upper Confidence Limits

s r – Repeatability Standard Deviation s R – Reproducibility Standard Deviation