Microbiology Methods for ERP Review 3-2020

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( d ) Allow heated samples to cool to room temperature (15–25°C). This may be accelerated by 1 placing the test tubes in cold water for 5 min. 2 ( e ) Where appropriate frit filters will be used with denatured matrices that contain high 3 concentrations of particulates thereby minimizing sample handling errors. 4 ( f ) Change pipette tips in between samples.

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Pathogen Detection (Automated Sample Preparation Method)

( a ) Equilibrate test kit to room temperature (15–25°C) an hour before use. ( b ) Start the Dynex DS2 and allow instrument to conduct the ‘Self ‐ Test’. ( c ) Load required materials: pipette tips, reagents, washing buffer, etc.

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( d ) Empty waste.

( e ) Start heating block or heat water to 85–100°C prior to initiating testing.

( f ) Allow heated samples to cool to room temperature (15–25°C). This may be accelerated by

placing the test tubes in cold water for 5 min.

( g ) Where appropriate use frit filters with denatured matrices that contain high concentrations of

particulates to minimize sample handling errors.

F. Sample Enrichment and Preparation

( a )

Raw Beef Trim (375 g test portions)

Pre ‐ warm 1,125 mL of Solus BPW (ISO) Medium supplemented with Solus Salmonella supplement 22 [4.44 mL Solus Salmonella supplement per 1,000 mL Solus BPW (ISO)] to 37 ± 1°C for at least 2 h prior to 23 its addition to a 375 g test portion in the sampling bag. Homogenize by hand massaging for 2 min ± 30 s 24 and incubate at 41.5 ± 1°C for 20–22 h. 25 ( b ) Pasteurized Liquid Egg (100 g test portions) 26 Pre ‐ warm 900 mL of Solus BPW (ISO) Medium supplemented with Solus Salmonella supplement 27 [4.44 mL Solus Salmonella supplement per 1,000 mL Solus BPW (ISO)] to 37 ± 1°C for at least 2 h prior to 28 its addition to a 100 g test portion in the sampling bag. Homogenize by hand massaging for 2 min ± 30 s 29 and incubate at 41.5 ± 1°C for 20–22 h. 30 ( c ) Raw Salmon (fillet), Cheddar Cheese (shredded) and Romaine Lettuce (bagged) (25 g test 31 portions) 32 Add 225 mL of Solus BPW (ISO) Medium supplemented with Solus Salmonella supplement [4.44 mL 33 Solus Salmonella supplement per 1,000 mL Solus BPW (ISO)] to a 25 g test portion in the sampling bag. 34 Homogenize for 2 min ± 30 s and incubate at 41.5 ± 1°C for 20–22 h. 35 ( d ) Paprika (powder) and Black Peppercorns (whole) (25 g test portions) 36 Add 225 mL of Solus mBPW Medium supplemented with Solus Salmonella supplement [2.22 mL 37 Solus Salmonella supplement per 1,000 mL Solus mBPW] to a 25 g test portion in the sampling bag. 38 Homogenize for 2 min ± 30 s and incubate at 41.5 ± 1°C for 20–24 h. 39 ( e ) Cinnamon (powder) (25 g test portions) 40 Add 1,225 mL of Solus mBPW Medium supplemented with Solus Salmonella supplement [2.22 mL 41 Solus Salmonella supplement per 1,000 mL Solus mBPW] to a 25 g test portion in the sampling bag. 42

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