Enzyme Linked Immunosorbent Assay. A sample containing an unknown amount of antigen is immobilised on the surface of a micro titre plate. An enzyme labelled antibody specific to the antigen of interest is added and forms a complex with the antigen, a series of washes are then carried out to remove any proteins or antibodies that are not specifically bound. Finally the substrate is added and converted to visible signal which corresponds directly to the quantity of antigen in the sample.
