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3M MDA2 E. coli O157:H7 Collaborative Study
May 2016
OMA-2016-May-XXXX
DRAFT DOCUMENT
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d)
Serological Pipette Bulbs (Automatic Pipette)
– For sampling and delivering of 1 mL - 10 mL
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e)
Serological pipettes
. – Aerosol resistant
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f)
Stomacher®
. – Seward or equivalent
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g)
Filter Stomacher® bags
. – Seward or equivalent
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h)
Sterile collection sponge and swab
. – Environmental surface sampling
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i)
Thermometer
. – Calibrated range to include 100 ± 1°C range
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j)
Incubators
. – Capable of maintaining 35±2°C, 42±1°C and 41.5±1°C
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k)
Dry Bath Incubator
. – Capable of maintaining a temperature of 100 ± 1 ºC
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l)
Dry double block heater unit.
– Capable of maintaining 100 ± 1°C; or
a water bath
capable of
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maintaining 100 ± 1°C
10
m)
Refrigerator
. – capable of maintaining 2-8°C, for storing the 3M MDA2
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n)
Computer
. – compatible with the 3M Molecular Detection System (instrument)
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g)
Safety Precautions
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The 3M™ Molecular Detection Instrument is intended for use with samples that have undergone
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heat treatment during the assay lysis step, which is designed to destroy organisms present in
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the sample. Samples that have not been properly heat treated during the assay lysis step may
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be considered a potential biohazard and should NOT be inserted into the 3M Molecular
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Detection Instrument.
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The user should read, understand and follow all safety information in the instructions for the 3M
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Molecular Detection System and the 3M MDA2 –
E. coli
O157 (including H7). Retain the safety
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instructions for future reference.
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h)
Sample Preparation
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a)
Foods -
3M recommends the use of 3M BPW ISO for the enrichment of food samples. It is
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the user’s responsibility to validate alternate sampling protocols or dilution ratios to ensure
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this test method meets the user’s criteria.
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(1)
Pre-warm BPW ISO enrichment medium to 41.5 ± 1°C.
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(2)
Aseptically combine the enrichment medium and sample according to information
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below. For all meat and highly particulate samples, the use of filter bags is
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recommended.
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(a)
Ground beef – 325g + 975 mL BPW ISO (pre-warmed to 41.5 ± 1°C). Homogenize the
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sample for 2 ± 0.2 min. Incubate at 41.5 ±1°C for 10-18 hr.
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(b)
Sprouts – 25g + 225 mL 3M BPW ISO (pre-warmed to 41.5 ± 1°C ). Homogenize the
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sample for 2 ± 0.2 min. Incubate at 41.5 ±1°C for 18-24 hr.
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(c)
Frozen whole blueberries – 25g + 225 mL 3M BPW ISO (pre-warmed to 41.5 ± 1°C ).
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Gently agitate the sample for 2 ± 0.2 minutes (DO NOT STOMACH). Incubate at 41.5
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±1°C for 18-24 hr.
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(d)
Spinach – Add 200g + 450 mL BPW ISO (pre-warmed to 41.5 ± 1°C ) in a sterile re-
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sealable plastic bag and gently agitate by hand. Incubate at 41.5 ±1°C for 18-24 hr.
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(e)
Run the 3M Molecular Detection Instrument following the 3M Molecular Detection
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System User Manual – Reserving enriched test portion for confirmation.
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i)
Post-enrichment
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OMAMAN-35 B: Collaborative Study Protocol
ERP USE ONLY
January 2017
AOAC Research Institute
Expert Review Panel Use Only