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Periodically decontaminate laboratory benches and equipment (pipettes, cap/decap tools, etc.)
1
with a 1- 5% (v:v in water) household bleach solution or DNA removal solution.
2
3
S
AMPLE
E
NRICHMENT
4
Table 2 presents guidance for the enrichment of food and environmental samples. It is the
5
user’s responsibility to validate alternate sampling protocols or dilution ratios to ensure this test
6
method meets the user’s criteria.
7
8
Foods
9
5.
Allow the Demi-Fraser Broth enrichment medium (includes ferric ammonium citrate) to
10
equilibrate to ambient laboratory temperature.
11
6.
Aseptically combine the enrichment medium and sample according to Table 2. For all meat
12
and highly particulate samples, the use of filter bags is recommended.
13
7.
Homogenize thoroughly by blending, stomaching, or hand mixing for 2 ± 0.2 minutes.
14
Incubate at 37 ±1°C according to Table 2.
15
8.
For raw dairy products, transfer 0.1 mL of the primary enrichment into 10 mL of Fraser
16
Broth. Incubate at 37 ±1°C for 20-24 hours.
17
18
Environmental samples
19
Sample collection devices can be a sponge hydrated with a neutralizing solution to inactivate
20
the effects of the sanitizers. 3M recommends the use of a biocide-free cellulose sponge.
21
Neutralizing solution can be Dey-Engley (D/E) Neutralizing Broth or Letheen broth. It is
22
recommended to sanitize the area after sampling.
23
24
25
WARNING: Should you select to use Neutralizing Buffer (NB) that contains aryl sulfonate
26
complex as the hydrating solution for the sponge, it is required to perform a 1:2 dilution (1 part
27
sample into 1 part sterile enrichment broth) of the enriched environmental sample before testing
28
in order to reduce the risks associated with a false-negative result leading to the release of
29
contaminated product
30
31
The recommended size of the sampling area to verify the presence or absence of the pathogen
32
on the surface is at least 100 cm
2
(10 cm x 10 cm or 4”x4”). When sampling with a sponge,
33
cover the entire area going in two directions (left to right then up and down) or collect
34
environmental samples following your current sampling protocol or according to the FDA BAM
35
AOAC Research Institute
Expert Review Panel Use Only
OMAMAN-29/OMAMAN-30 Combined Collaborative Study Protocol
OMA ERP - June 2016
ERP Use Only