ERP Micro December 2019

Validation Study to Demonstrate the Equivalence of a Matrix Extension and Minor Modifications of Assurance® GDS for E . coli O157:H7 Tq Method to the Reference Culture Method Summary of Proposed Changes The objective of this study is to demonstrate equivalance of a matrix extension and two minor modifications for the GDS EHEC method to the reference methods. First is the extension of matrices to include finely textured beef (FTB, 375 g), carcass cloths and green onions (25 g). The FTB samples will be frozen when added to the media for enrichment. Secondly, a modification is the use of an automated DNA extraction system, Assurance® GDS PickPen TM PIPETMAX® (PPMX), for sample preparation. The PPMX is a modular automated system to complete the routine pipetting and the PickPen TM IMS concentration of target organism. The machine automates all reagent dispensing, performs the PickPen TM IMS protocols and dispenses concentrated DNA into the Amplification tubes. The PPMX will be validated as an alternative sample preparation method alongside the standard method for GDS EHEC for beef trim, FTB and carcass cloths. Finally, the third modification is an alternative amplification tube size for the assay. A smaller alternative tube size for the amplification tube (HT, High Throughput) has previously been developed for GDS EHEC. The internal amplification contents remain unchanged; only the exterior tube size is modified. The HT amplification tube will also be validated alongside the standard (size) amplification tube for GDS EHEC for use by the manual and automated DNA extraction methods by demonstrating consistency of the two tube formats. The HT amplification tubes will be analyzed on beef trim, FTB and carcass cloth.