Chemiluminescent and colorimetric enzymatic assays for the detection of PCR-amplified Salmonella sp. products in microplates.

To improve Salmonella detection, we developed nonradioactive hybridization assays of amplified products from pure Salmonella cultures. Biotin-labeled PCR products were trapped by internal probes covalently bound to CovaLink-NH MicroWells and detected by colorimetric or chemiluminescent enzymatic reactions. The sensitivities of colorimetric assays using peroxidase and alkaline phosphatase were similar to those obtained with an ethidium bromide-stained agarose gel; both procedures allow the detection of 50 Salmonella cells. Chemiluminescence was 10-fold more sensitive than colorimetry.