Purpose: To compare the equivalence of sample preparation for analysis performed manually using the PickPen device and in an automated manner utilizing the Assurance GDS PickPen PIPETMAX (PPMX) instrument equipped with a PickPen head in a variety of foods by multiple of methods.
Methods: A total of 556 samples of various matrices were analyzed by multiple methods. Inoculated samples were enriched according to kit directions for use. Paired samples were taken. One set was prepared manually while the other set was processed by the PPMX. Both sets of prepared samples were analyzed on the BioControl Rotor-Gene Q instrument. Positives were confirmed and matched for the two sample comparative preparation methods and Ct (amplification cycle threshold) values compared for all positive samples.
Results: A total of 556 samples were tested. Four hundred and thirty-one (431) samples were confirmed positive with both the manually processed and those prepared using the PPMX automated system. One hundred twenty-five (125) samples were negative by both methods. There were no discrepant results. The mean Ct values across all the positive curves were within 0.2 of each other. Seven different detection assays were evaluated. In total, 22 different foods and two surfaces were tested.
Significance: This validation study demonstrates the equivalence of the evaluated sample preparation method comparing manual processing with the new automated system, the Assurance GDS PickPen PIPETMAX.