ELISA and Monoclonal Antibodies

Immunochemical methods have been used extensively to identify and quantify biologically important substances. The nature of the “antigen-antibody reaction” enables researchers to selectively monitor molecules of interest among a mixture of potentially interfering materials found in complex biological samples. Classical immunochemical techniques such as immunodiffusion and immunoprecipitation (see Chapter 1) do not in some cases offer sufficient detection sensitivity and are incapable of handling the large number of samples that are currently routinely processed. With the advent of radioimmunoassay (RIA: see Chapter 6), an analytical immunochemical technique has become available for measuring minute amounts of biologically active substances such as hormones, enzymes, and neuropeptides.