AOAC RI ERP Final Action Recommendations eBook

Dupont BAX Salmonella PTM Report Modification Approved 2012 / PTM Certification No. 081201 For Expert Review Panel Use Only Do Not Distribute

MODIFICATION TO THE BAX® SYSTEM REAL-TIME PCR ASSAY FOR 1 SALMONELLA ( PERFORMANCE TESTED METHOD SM #081201) IN 2 SELECTED FOODS: ADDITION OF EIGHT PCR CYCLES TO IMPROVE 3 SENSITIVITY 4

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1. ABSTRACT

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In August 2012, the AOAC Research Institute (AOAC-RI) certified the BAX® System Real-Time 7 PCR Assay for Salmonella as comparable to the USDA-FSIS, U.S. FDA and Health Canada reference 8 methods for detecting Salmonella in raw ground beef, chicken carcass rinses, cream cheese, bagged 9 lettuce, dry pet food and stainless steel environmental samples. 10 11 low-level positive samples could be improved by slightly extending the processing time. Internal studies 12 showed that adding eight cycles to the PCR program for the real-time Salmonella assay minimizes the risk 13 of a false negative result for samples at or near the limit of detection, and slightly increases the method’s 14 sensitivity. 15 16 temperature profile of the PCR and detection process, and all step-by-step instructions for sample 17 enrichment and preparation. Moreover, because the real-time Salmonella assay already incorporates a 18 “hot-start” polymerase and Scorpion™ probe technology, the risk of non-specific product formation, or 19 other potentially negative effects from slightly extended PCR, is minimal. 20 21 method to both the current certified method and the appropriate reference culture methods on a range of 22 artificially contaminated matrices. In addition, inclusivity and exclusivity studies were performed to 23 demonstrate no significant change in the sensitivity and specificity of the assay. Since then, expanded use in real-world samples and additional research suggests that results for All components of the certified method remain unaltered, including PCR tablet chemistry,

AOAC INTERNATIONAL Several studies were conducted to compare the performance of the updated BAX® System

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