Expand ELISA. On what principle is ELISA test based?

Perlmann and Engvall described the Enzyme-linked immunosorbent assay (ELISA) in 1971, and it is a widely used analytical biochemistry assay. The assay employs a solid-phase enzyme immunoassay to detect the presence of ligand in a liquid sample by using antibodies directed against the protein. ELISA is an enzyme-linked immunosorbent assay that is used in analytical biochemistry and aids in disease detection.

The ELISA is based on the principle of antibody-antigen interactions, which states that specific antibodies bind to the target antigen. When the interaction occurs, the substrate will be able to bind to the enzyme, and substrate conversion will occur, yielding a positive result.

These methods can detect the interaction in two ways, which are listed below:

1. Sandwich ELISA: The sample is sandwiched between two layers of antibodies, and if an interaction occurs, a substrate reaction is observed in addition to a conjugated antibody and substrate. This technique aids in the detection of rotavirus and HIV in the body.

2. Direct ELISA: In this method, the sample is added first, followed by the enzyme-conjugated antibody. If any interaction occurs, the reaction will be visible upon substrate addition.

 Enzyme-linked immunosorbent assay (ELISA). The ELISA is based on the principle of antibody-antigen interactions, which states that specific antibodies bind to the target antigen. Teh two ways by which an infection can be detected using ELISA test is Sandwich ELISA and Direct ELISA.