AOAC-RI ERP Micro June 2016

OMAMAN-29/OMAMAN-30 Combined Collaborative Study Protocol OMA ERP - June 2016 ERP Use Only

Periodically decontaminate laboratory benches and equipment (pipettes, cap/decap tools, etc.) 1 with a 1- 5% (v:v in water) household bleach solution or DNA removal solution.

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S AMPLE E NRICHMENT 4 Table 2 presents guidance for the enrichment of food and environmental samples. It is the 5 user’s responsibility to validate alternate sampling protocols or dilution ratios to ensure this test 6 method meets the user’s criteria. 9 5. Allow the Demi-Fraser Broth enrichment medium (includes ferric ammonium citrate) to 10 equilibrate to ambient laboratory temperature. 11 6. Aseptically combine the enrichment medium and sample according to Table 2. For all meat 12 and highly particulate samples, the use of filter bags is recommended. 13 7. Homogenize thoroughly by blending, stomaching, or hand mixing for 2 ± 0.2 minutes. 14 Incubate at 37 ±1°C according to Table 2. 15 8. For raw dairy products, transfer 0.1 mL of the primary enrichment into 10 mL of Fraser 16 Broth. Incubate at 37 ±1°C for 20-24 hours. 19 Sample collection devices can be a sponge hydrated with a neutralizing solution to inactivate 20 the effects of the sanitizers. 3M recommends the use of a biocide-free cellulose sponge. 21 Neutralizing solution can be Dey-Engley (D/E) Neutralizing Broth or Letheen broth. It is 22 recommended to sanitize the area after sampling. 23 24 25 WARNING: Should you select to use Neutralizing Buffer (NB) that contains aryl sulfonate 26 complex as the hydrating solution for the sponge, it is required to perform a 1:2 dilution (1 part 27 sample into 1 part sterile enrichment broth) of the enriched environmental sample before testing 28 in order to reduce the risks associated with a false-negative result leading to the release of 29 contaminated product 30 31 The recommended size of the sampling area to verify the presence or absence of the pathogen 32 on the surface is at least 100 cm 2 (10 cm x 10 cm or 4”x4”). When sampling with a sponge, 33 cover the entire area going in two directions (left to right then up and down) or collect 34 environmental samples following your current sampling protocol or according to the FDA BAM 35 AOAC Research Institute Expert Review Panel Use Only 7 8 Foods 17 18 Environmental samples

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