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3M Molecular Detection Assay Salmonella Collaborative Study
July 2012
OMA-2012-July-XXX
5.5.10
Refrigerator
. – capable of maintaining 2-8°C, for storing the 3M
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Molecular Detection Assay
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5.5.11
Computer
. – compatible with the 3M Molecular Detection Instrument
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5.6
Determination
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5.6.1
Enrichment
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5.6.1.1
Raw ground beef
- aseptically add the 25g test portion to 225 mL
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pre-warmed (37°C) 3M BPW ISO.
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5.6.1.1.1
Homogenize thoroughly in a filter bag for 2 min.
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5.6.1.1.2
Incubate 8 hr at 37 ± 1°C.
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5.6.1.2
Wet dog food
- aseptically add the 375g test portion to 3375 mL
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pre-warmed (37°C) 3M BPW ISO.
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5.6.1.2.1
Homogenize thoroughly in a filter bag for 2 min.
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5.6.1.2.2
Incubate 18 hr at 37 ± 1°C.
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5.6.2
Prepare the 3M Molecular Detection speed loader tray, chill block insert,
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heat block insert and instrument.
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5.6.3
Transfer 20 µL enriched sample into a LS tube.
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5.6.4
Transfer 20 µL Negative Control [NC] into a Lysis Solution [LS] tube
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after all enriched samples have been completed.
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5.6.5
Invert 3-5 times and heat 15±1 min at 100±1°C.
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5.6.6
Place tubes (without rack lid) in chill block insert for 10±1 min.
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5.6.7
Replace rack lid and invert 3-5 times. Allow to sit on bench at least 5 min.
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5.6.8
Transfer 20 µL sample lysate from the upper portion of fluid in the LS
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tube into regent tube. Mix gently by pipetting up and down 5 times.
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5.6.9
Transfer 20 µL of NC lysate into a reagent tube.
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5.6.10
Transfer 20 µL of NC lysate into a Reagent Control (RC) tube.
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5.6.11
Load capped tubes into speed loader tray and close lid.
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5.6.12
Start assay.
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5.6.13
Results and Interpretation - An algorithm interprets the light output curve
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resulting from the detection of the nucleic acid amplification. Results are
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analyzed automatically by the software and are color-coded based on the
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result. A Positive or Negative result is determined by analysis of a number
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of unique curve parameters. Presumptive positive results are reported in
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real-time while Negative and Inspect results will be displayed after the run
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is completed. Presumptive positive results should be confirmed using your
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preferred method or as specified by local regulations.
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NOTE:
Even a negative sample will not give a zero reading as the
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system and 3M Molecular Assay
Salmonella
amplification reagents
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have a “background” relative light unit (RLU).
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In the rare event of any unusual light output, the algorithm labels this
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as “Inspect.” 3M recommends the user to repeat the assay for any
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Inspect samples. If the result continues to be Inspect, proceed to
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DRAFT DOCUMENT
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