ELISA

Enzyme Linked Immunosorbent Assay.

For the detection of proteins, viruses or low molecular weight compounds (for example: hormones, pesticides and toxins) and their concentration determination the Enzyme Linked Immunosorbent Assay is used.

In this enzyme immunoassays (EIA) a polystyrene multiwell plate is coated with a specific antibody (capture antibody) against the sample (analyte or antigens). This immobilized antibody binds a specific amino acid sequence (epitope) on the analyte. This is followed by incubation with a second antibody (detection antibody) which can be both monoclonal origin (from hybridoma cells) as well as polyclonal (from animal serum). If these antibodies are already conjugated to a fluorophore or an enzyme, the detection can be done directly. In the event that the second antibody is uncoupled a further conjugated antibody is necessary for the detection (indirect ELISA). Thus, a characteristic color change after the addition of a substrate or a monochromatic excitation (in the case of a fluorophore-conjugated antibody) can be achieved.

The  assay formats can also be divided into direct and indirect ELISA test, sandwich ELISA test and competitive or inhibitory ELISA test.

An ELISA kit offers you additional flexibility, by the ability to coat the polystyrene multiwell plate on your own.

Descriptive information about ELISA is available in our Data Library.