3M Listeria MDAL96 Manual Del Usuario página 7

3M Molecular Detection Assay Listeria Protocols using Demi-Fraser Broth Base
AOAC® Official Method of Analysis
AOAC® Performance Tested Methods
In AOAC OMA and PTM studies, the 3M Molecular Detection Assay Listeria was found to be an effective method for the detection of Listeria using
Demi-Fraser Broth Base. The matrices tested in the study are shown in Table 3. The limit of detection of the 3M Molecular Detection Assay Listeria
method is 1-5 colony forming units per validated test portion size.
Table 3: Enrichment protocols using Demi-Fraser Broth Base (no FAC).
Sample Matrix
Full fat cottage cheese
Beef hot dogs
Deli turkey
AOAC OMA
2014.06
Cold smoked salmon
AOAC PTM
#081203
(modification)
Environmental
Surfaces
Bagged raw Spinach
AOAC PTM
#081203
(modification)
Whole cantaloupe
Environmental
For Other
Heat-processed dairy
Matrices
Other foods**
*A 24-26 hr primary enrichment in Demi-Fraser Broth Base (no FAC) followed by a 24-26 hr secondary enrichment in Fraser Broth Base (no FAC) is
also acceptable for these matrices.
**Other Foods includes meat, poultry, fish, seafood, produce, vegetable and vegetable-based products, and raw dairy.
(OMA) 2014.06
SM
(PTM) Certificate #081203
SM
Demi-Fraser Broth Base (no FAC)
Sample
Size
Broth
Enrichment
Volume
(mL)
25 g 225
25 g 225
25 g 225
25 g 225
Stainless
1 swab 10
steel
Concrete 1 sponge 100
Stainless
steel, 1 sponge 225
concrete
25 g 225
Enough
volume to
allow melon
to float
[volume
1 melon
may be
1.5 times
the weight
of the
cantaloupe]
1 swab 10
1 sponge 100
1 sponge 225
25 g 225
25 g 225
Primary Enrichment
Enrichment
Enrichment
Temperature
Time (hr)
(±1°C)
37 24-28
37 24-28
37 24-28
37 24-28
37 26-30
37 24-26
37 24-26
37 26-30
37 24-28
37 24-26
6
(English)
Secondary Enrichment
Fraser Broth Base (no FAC)
Enrichment Enrichment
Medium Temperature
(mL) (±1°C)
Not required
Not required
Not required
Not required
Not required
Transfer 0.1
mL into 10
37
mL Fraser
Broth Base
Transfer 0.1
mL into 10
37
mL Fraser
Broth Base
Not required*
Not required*
Fraser broth
(no FAC): 0.1
37
mL into 10
mL
Enrichment
Time (hr)
24-26
24-26
24-26