An enzyme immunoassay for the detection of all Salmonella using a combination of a myeloma protein and a hybridoma antibody.

An enzyme immunoassay was developed for the detection of salmonellae in foods and stool samples. The test is sensitive and specific, showing virtually no cross-reactivity to other enteric organisms. The sensitivity is such that less than 10(6) Salmonella organisms can be detected, and this is not influenced even by a 3 log10 overgrowth of other bacteria. This assay can be performed routinely in any laboratory, and can be automated as much as desired. It can be performed from growth in liquid or on solid media. A myeloma protein (M467) and a hybridoma antibody (6H4) were attached to a polycarbonate coated metal bead. The beads were then incubated in a heat extract of the organisms for 20 min. After thorough washing by a magnetic transfer device, the beads were then incubated in a mixture of the 2 antibodies which were labeled with horseradish peroxidase. After another thorough washing and incubation in substrate, the reactions were either read by the naked eye or by spectrophotometry. The entire process following the culture takes less than 2 h.