AOAC-RI ERP Book MICRO Sept 2016.pdf

OMAMAN-08/Collaborative Study Protocol March 2014 Expert Review Panel Use Only

3M Petrifilm SALX Collaborative Study

July 2013

OMA-2013-July-XXX

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5.5.3 Sterile serological pipettes. – capable of 1mL 5.5.4 Pipettes . – capable of 100µL 5.5.5 Sterile pipette tips. – capable of 100µL 5.5.6 Stomacher® . – Seward or equivalent 5.5.7 Filter Stomacher® bags . - Seward or equivalent 5.5.8 Incubators . – capable of maintaining 41.5° ± 1°C 5.5.9 Incubator -capable of maintaining 35°C± 1°C

5.5.10 5.5.10Waterbath- capable of maintaining 42°C± 0.2°C(circulating,

thermostatically controlled)

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5.5.11 Freezer . – capable of maintaining -10° to -20°C, for storing opened SALX

pouches , hydrated SALX plates, SALX plates after incubation

5.5.12 5.5.11Refrigerator . – capable of maintaining 2° - 8°C, for storing unopened

3M SALX plates and SALX disks

5.5.13 Sterile distilled water 5.5.14 Sterile reverse osmosis water

5.5.15 Sterile Butterfield’s Phosphate Diluent

5.5.16 3M Petrifilm Flat Spreader

Enrichment

5.6

5.6.1.1 Raw ground beef (25g, high microbial load)

5.6.1.1.1

Aseptically add the 25g test portion to 225 mL pre-warmed (41.5°C)

3M Salmonella Enrichment Base with supplement. Mix in a Stomacher® bag with filter for 2 min.

5.6.1.1.2 5.6.1.1.3 5.6.1.1.4

Incubate 18-24 hr at 41.5 ± 1°C.

After primary enrichment incubation, transfer 0.1 mL of the primary enrichment into 10.0 mL Rappaport-Vassiliadis R10 (R-V R10) Broth.

Incubate at 41.5 ± 1.0°C for 8-24 hours.

5.6.1.2 Dry dog food (375g, low microbial load)

5.6.1.2.1

Aseptically add the 375g test portion to 3375 mL pre-warmed (41.5°C) 3M Salmonella Enrichment Base with supplement.

5.6.1.2.2 5.6.1.2.3

Mix in a Stomacher® bag with filter for 2 min. AOAC Research Institute Expert Review Panel Use Only Incubate 18-24 hr at 41.5 ± 1°C.

Plate Hydration

5.7

5.7.1 Use prescribed sterile diluents to hydrate the 3M Petrifilm SALX Plates: Butterfield’s Phosphate Diluent, distilled water, or reverse osmosis water. 5.7.2 Place the 3M Petrifilm SALX Plate on a flat, level surface (figure A). 5.7.3 Lift the top film and with the pipette perpendicular dispense 2.0 mL ± 0.1 mL of sterile diluent onto the center of bottom film (figure B). Do not close the top

film before dispensing the entire 2.0 mL volume.

5.7.4 Gently roll down the top film onto the diluent to prevent trapping air bubbles

(figure C).

5.7.5 Place the 3M TM Petrifilm TM Flat Spreader (Catalog #6425) on the center of the plate. Press gently on the center of the spreader to distribute the diluent evenly.

DRAFT DOCUMENT

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