The Alert Test Kit for Detecting Salmonella

Laboratory Procedure MFLP-97
February 2001

1. APPLICATION

The method is applicable to the detection of Salmonella from feeds, raw foods and other samples to determine compliance with Sections 4 and 7 of the Food and Drugs Act. Where stipulated, the Official Methods and HPB Method should be used.

2. DESCRIPTION

The method has been shown to produce satisfactory results with artificially contaminated foods and naturally contaminated poultry rinse, raw ground turkey and rendered poultry meal in AOAC studies
(8.1). This method can be used successfully for the detection of Salmonella in other foods and food ingredients.

3. PRINCIPLE

Alert for Salmonella is a sandwich ELISA utilizing both monoclonal and polyclonal antibodies made against a Salmonella antigen. Following selective enrichment in tetrathionate broth and rappaportvasiliadis broth and post enrichment in M broth, test cultures are heated to release the antigen and then added to a microwell containing the bound polyclonal antibodies. During this first incubation, the antigen is captured by the bound antibodies. After a wash step, peroxidase-conjugated anti-Salmonella monoclonal antibody is added and allowed to react with the captured antigen. After a second wash, substrate is added which reacts with the peroxidase complex and develops blue color. The more blue color is indicative of the more Salmonella antigen present in the sample culture. A stop solution is added and the microwells are read on an EIA reader at 450 nm.

4. DEFINITION OF TERMS

See Appendix A of Volume 3.

5. COLLECTION OF SAMPLES

See Appendix B of Volume 3.

6. MATERIALS AND SPECIAL EQUIPMENT

The media listed under No. 2 to 11 are commercially available and are to be prepared and sterilized according to the manufacturer's instructions.

1) Alert Test Kit (Neogen Corporation,
phone: (517) 372-9200
Fax: (517) 372-0108)

2) Lactose broth

3) Tryptic soy broth