AOAC-RI ERP Book Micro Jan 19 2017

OMAMAN-35 A : Collaborative Study Manuscript For ERP Use Only January 2017

the 3M MDA 2 – E. coli O157 (including H7) method were compared to samples analyzed using the USDA/FSIS 1 MLG reference method in an unpaired study design. All positive test portions were biochemically confirmed by 2 the API 20E biochemical testor by the VITEK 2 GNbiochemical identification test, AOAC Official Method 3 2011.17 [7]. 6 7 Each collaborating laboratory recorded results for the reference method and the 3M MDA 2 – E. coli O157 8 (including H7) method on the data sheets provided. The data sheets were submitted to the study director at the end 9 of testing for statistical analysis. Data was analyzed using the Least Cost Formulations, Ltd., AOAC Binary Data 0 Interlaboratory Study Workbook ( http://lcfltd.com/aoac/aoac-binary-v2-3.xls) provided by AOAC RI [8]. Data for 1 each test portion size was analyzed using the probability of detection (POD)statistical model [9].The probability of 2 detection (POD) was calculated as the number of positive outcomes divided by the total number of trials. The POD 3 was calculated for the candidate presumptive results, POD CP, the candidate confirmatory results (including false 4 negative results), POD CC , the difference in the candidate presumptive and confirmatory results, dLPOD CP, 5 presumptive candidate results that confirmed positive (excluding false negative results), POD C, the reference 6 method, POD R , and the difference in the confirmed candidate and reference methods, dLPOD C . A 7 dLPOD C confidence interval not containing the point zero would indicate a statistically significant difference 8 between the 3M MDA 2 – E. coli O157 (including H7)and the reference methods at the 5 % probability level. In 9 addition to POD, the repeatability standard deviation (s r ), the among laboratory repeatability standard deviation 0 (s L ), the reproducibility standard deviation (s R )and the P T value were calculated. The s r provides the variance of 1 data within one laboratory, the s L provides the difference in standard deviation between laboratories and the s R 2 provides the variance in data between different laboratories. The P T value provides information on the 3 homogeneity test of laboratory PODs [9]. 4 5 Statistical Analysis First Action 2016 9 0 (Applicable to detection of Escherichia coli O157 (including H7) in raw ground beef (73% lean), frozen 1 blueberries, fresh sprouts, and fresh baby spinach. 2 3 See Table 2016.1A for a summary of results of the inter-laboratory study. 4 See Table 2016.2A for detailed results of the inter-laboratory study 7 8 The 3M ™ Molecular Detection Assay (MDA) 2 – E. coli O157 (including H7) method is used with the 3M ™ 9 Molecular Detection System (MDS) for the rapid and specific detection of E. coli O157 (including H7) in enriched 0 foodsamples. The 3M MDA2 – E. coli O157 (including H7)uses loop-mediated isothermal amplification of unique 1 DNA target sequences with high specificity and sensitivity, combined with bioluminescence to detect the 2 amplification. Presumptive positive results are reported in real-time while negative results are displayed after the 3 assay is completed, 60 minutes. Samples are enriched in 3M ™ Buffered Peptone Water (BPW) ISO formulation. 6 Items (a)-(g) are available as the 3M ™ Molecular Detection Assay (MDA) 2 – E. coli O157 (including H7) 7 kit from 3M Food Safety (St. Paul, MN 55144-1000, USA). 8 AOAC Research Institute Expert Review Panel Use Only 5 6 A. Principle 4 5 B. Apparatus and Reagents 4 5 6 7 8 AOAC Official Method 2016.xx Escherichia coli O157:H7in Selected Foods 3M ™ Molecular Detection Assay(MDA) 2 – E. coli O157 (Including H7) Method

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