[Theoretic scheme of immunoenzyme analysis (the "sandwich" variant)]

The sandwich variant of the enzyme-linked immunosorbent assay (ELISA) is a simple serological reaction of three components, and the antigen-antibody interaction follows the law of active masses. To increase the sensitivity of ELISA with respect to the antigen, the plates should be sensitized with moderate concentrations of antibodies and the confugate should be introduced at relatively low concentrations. To increase the activity of the conjugate, the plates should be sensitized with high concentrations of antibodies, but in this case the sensitivity of ELISA will not be high.