The ELISA, Enzyme-Linked Immunosorbent Assay

Featured Article: Engvall E, Perlmann P. Enzyme-linked immunosorbent assay (ELISA). Quantitative assay of immunoglobulin G. Immunochemistry 1971;8:871–4.1 This paper was my first as a graduate student of Professor Peter Perlmann at Stockholm University. At the time, RIAs were in full bloom, but they were too sophisticated for many areas of research and diagnosis because they required expensive equipment and used antigens and antibodies labeled with radioactive isotopes with short half-lives. We wanted something simpler with the same sensitivity. Techniques for labeling antibodies with enzymes had been described for immunohistochemistry (1), and we thought they could be useful for serologic assays as well. First, we gave the prospective enzyme immunoassay a name: enzyme-linked immunosorbent assay, or ELISA (an important decision). Second, we chose to use an enzyme for which there was, at the time, a soluble and sensitive substrate–product system, namely alkaline phosphatase. Third, we used the procedure of a standard …