AOAC 2018 Methods

rehydration of a sponge with 25 mL BPW, rinsing aseptically, swabbing 100 cm surface and adding

sponge to buffer and stomaching for 1–2 min.

( c ) Chicken Ccarcasses .--The sampling protocol followed FSIS Directives for chicken carcass (1, 2). 400mL BPW or n-BPW were added to a bag with a chicken carcass, bag was sealed and shaken for 1 minute (3).

100 mL of rinsate was collected for testing.

E. Procedure

( a ) Place Peel Plate onto a level surface. Apply pressure with fingers to the rear rectangular platform to keep plate flat. ( b ) Lift cover vertically upwards completely exposing the dried media culture disc. Leave cover adhered to back of plate. ( c ) While holding cover up, keep plate flat on surface, vertically dispense 1.0 mL of sample or sample dilution to the center of exposed Peel Plate disc. Expel pipet contents rapidly with even force and within

2 to 3 s. Sample will self-wick to the edges of the disc. It is acceptable to lift and rotate plate to swirl

sample to edges when sample conditions interfere with wicking.

( 1 ) In the case of cereal, 5 plates, should be rehydrated per sample. Alternatively, 5 mL homogenized

sample are added to one high volume plate.

( d ) Re-apply the adhesive cover without wrinkling. Press cover around edges of plate to ensure proper seal. ( e ) Incubate plates with adhesive cover down, clear side up. ( 1 ) Incubate at 37 ± 1°C for 24 up to 48 h.

( 2 ) Plates can stack by aligning the 3 feet. Stacking up to 20 will not affect plate heat transfer.

F. Interpretation and Test Result Report

( a ) At the end of incubation period, observe plates for colonies viewed through the clear side of the Peel Plate ECB. Each colored spot, regardless of color, represents one CFU. The sum of spots is reported as

3