ENZYME LINKED IMMUNO SORBENT ASSAY(ELISA)

An antibody (Ab) reacts with the concerned antigen (Ag) in a highly specific manner reacts only with that determinant or region of an antigen for which it is to produce an complex. When soluble protein react with the Ab Ag complex aggulatinates. In either case either the amount Ag of Ab complex formed or the rate of its formation is used to determine either quality of the antigen or the antibody involved in the interaction. The various assay used for the purpose are follows.
(1) preciptin reaction (2) the luchterlony electrophoresis are reaction in gels (3) aggulation reaction and (5) labelled antibody reactions.

Elisa Procedure: A generalized procedure and the basis principle of ELISA as follows. The antigen of interest in immobilized on the surface of the test tube petriplate or microtier well for convenient handling of large numbers of test sample these plate have allowed to react with the absorbed antigen unreacted molecules of the antibody are washed away leaving only the Ag-Ab complex. In secondary reaction antiglobulin react with the all the antibody is added into the vessel and allowed to react with the Ag-Ab complex. In an other approach unlabelled specific to antigen is immobilized in a micro titer well.