AOAC-RI ERP Book MICRO Sept 2016.pdf

OMAMAN-08/Collaborative Study Protocol March 2014 Expert Review Panel Use Only

3M Petrifilm SALX Collaborative Study

July 2013

OMA-2013-July-XXX

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Interpretation

5.10

5.10.1 Remove the 3M Petrifilm SALX Plates from the incubator and visually examine the isolated colonies. See Table 2. Do not count artifact bubbles that may be

present.

5.10.2 Note: Using indirect back lighting may enhance reading of colony color, discrete

yellow zones, and gas bubbles associated with a colony.

5.10.3 Presumptive positive Salmonella species are red to brown colonies with a yellow zone or associated gas bubble, or both (figure G). An associated gas bubble is defined as being located within one colony diameter distance from the colony

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(see Table 2 below).

Table 2: Interpretation for Presumptive Positive Salmonella species

Colony Color

Colony Metabolism

Result

Dark Red

Yellow zone

Red

Brown

Gas bubble





Presumptive +





Presumptive +







Presumptive +





Presumptive +





Presumptive +







Presumptive +





Presumptive +





Presumptive +







Presumptive +

AOAC Research Institute Expert Review Panel Use Only

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Non- Salmonella species (figure H):

• Blue colonies, green colonies, blue to green colonies, and/or black colonies with or without a yellow zone and/or associated gas bubble are non- Salmonella organisms. • Red, dark red, and brown colonies with no yellow zone and no associated gas are non-

Salmonella organisms.

• Red, dark red, and brown colonies with a magenta zone are non- Salmonella organisms.

If presumptive positive Salmonella colonies are not present, then report the results as

Salmonella not detected in the matrix.

If presumptive positive Salmonella colonies are present, then continue with the following

Biochemical Confirmation steps:

DRAFT DOCUMENT

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