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3M MDA 2
Listeria
species and
L. monocytogenes
Collaborative Study
OMA-2016-MONTH-XXX
5/4/16
5.3.9
Dey-Engley (D/E) Neutralizing Broth
5.3.10
Demi-Fraser Broth
5.4
Additional media
5.4.1
Fraser broth
5.4.2
Oxford Agar (OX)
5.4.3
Modified oxford agar (MOX)
5.4.4
Horse blood overlay agar (HL)
5.4.5
Sheep blood agar (SBA)
5.5
Apparatus
5.5.1
Pipettes
. – capable of 20µL
5.5.2
Multi-channel pipette
. – capable of 20µL
5.5.3
Sterile pipette tips.
– capable of 20µL
5.5.4
Stomacher®
. – Seward or equivalent
5.5.5
Filter Stomacher® bags
. - Seward or equivalent
5.5.6
Thermometer
. – calibrated range to include 100 ± 1°C range
5.5.7
Incubators
. – capable of maintaining 37 ± 1°C
5.5.8
Dry double block heater unit.
– capable of maintaining 100 ± 1°C;
OR
a water bath
capable of maintaining 100 ± 1°C
5.5.9
Freezer
. – capable of maintaining -10 to -20°C, for storing the 3M
Molecular Detection Chill Block Tray
5.5.10
Refrigerator
. – capable of maintaining 2-8°C, for storing the 3M
MDA
5.5.11
Computer
. – compatible with the 3M Molecular Detection System
(instrument)
5.6
Determination
5.6.1
Enrichment
5.6.1.1
Deli turkey
- aseptically add the 125g test portion to 1125 mL
Demi Fraser broth.
5.6.1.1.1
Homogenize thoroughly in a filter bag for 2 ± 0.2 min
5.6.1.1.2
Incubate 24-30 hr at 37 ± 1°C.
5.6.1.2
Raw chicken breast
- aseptically add the 25g test portion to 475
mL Demi Fraser broth.
5.6.1.2.1
Homogenize thoroughly in a filter bag for 2 minutes ±
30 seconds
5.6.1.2.2
Incubate 28-32 hr at 37 ± 1°C.
5.6.2
Prepare the 3M Molecular Detection speed loader tray, chill block insert,
heat block insert and instrument.
5.6.3
Equilibrate the LS tubes to room temperature (20-25 ºC) by setting LS
tube overnight 16-18 hours. Or on the laboratory bench for at least 2
hours.
5.6.4
Invert the capped LS tubes to mix, up to 4 hours before use.
5.6.5
Transfer 20 µL enriched sample into a LS tube.
AOAC Research I stitute
Expert Review Panel Use Only
OMAMAN-29/OMAMAN-30 Combined Collaborative Study Protocol
OMA ERP - June 2016
ERP Use Only