Comparative evaluation of different enzyme-linked immunosorbent assay systems for the detection of staphylococcal...

We compared four versions of the enzyme-linked immunosorbent assay for their suitability for detecting staphylococcal enterotoxins. The sandwich with labeled antibody proved to be the best. We used it with a sorbent consisting of antibody-coated polystyrene spheres reacted with 20 ml of food extract. The sensitivity of the test was 0.1 ng of enterotoxin per ml, which is far below clinical relevance. The succinimidyl-pyridyl-dithio-propionate enzyme coupling method of Pharmacia was superior to the two-step glutaraldehyde technique. Interfering protein A was eliminated by the simple addition of normal rabbit serum to the extracts. A diagnostic kit is now available.