Antigen Measurement Using ELISA

Abstract

The initial description of the enzyme-linked immunosorbent assay (ELISA) almost 30 yr ago (1) marked a technological advance that has had an immense impact in both clinical diagnostic and basic scientific applications. This assay represents a simple and sensitive technique for specific, quantitative detection of molecules to which an antibody is available. Although there are a huge number of variations based on the original ELISA principle, this chapter focuses on perhaps the two most useful and routinely performed: (1) the indirect sandwich ELISA---providing high sensitivity and specificity and (2) the basic direct ELISA---useful when only one antibody to the sample antigen is available.