Immunoassays

The enzyme immunoassay (EIA) is one of the most powerful of all immunochemical techniques. First described in the early 1970s, these assays are now used routinely in laboratory analyses and diagnostics. In biology and biotechnology, the EIA is a valuable and versatile tool used to detect and quantitate antigens and antibodies. Application of the appropriate EIA permits rapid quantification of different antigens and antibodies (referred to here as analytes) present at very low concentrations within a mixture. These assays are extremely sensitive and provide valuable information that would be difficult to determine by other techniques. Here we detail the development and optimization of the enzyme-linked immunosorbent assay (ELISA), a term generally used for any plate-based immunoassay that incorporates enzyme-, chemiluminescence-, or fluorescence-based reporters. It is amenable to standardization, automation, and large-scale sampling.