3M Petrifilm Environmental Listeria Plate.

A validation study of the 3M Petrifilm Environmental Listeria (EL) Plate (3M Food Safety, St. Paul, MN) was conducted at Q Laboratories, Inc., Cincinnati, OH. The method was compared to the Health Canada MFHPB-30 reference method for the analysis of stainless steel environmental surfaces. Twenty replicates of the environmental surface were analyzed at a low and a high inoculum level. The low-level sampling area was inoculated with 0.2-2 CFU/5 cm2, and the high-level sampling area was inoculated with 2-5 CFU/5 cm2. Five control replicates were also analyzed at 0 CFU/5 cm2. There was no significant difference in the number of positives detected by the 3M Petrifilm EL Plate method and the Health Canada MFHPB-30 reference method for the environmental surface analyzed in this study.