The ELISA, Enzyme-Linked Immunosorbent Assay
Featured Article: Engvall E, Perlmann P. Enzyme-
linked immunosorbent assay (ELISA). Quantitative
assay of immunoglobulin G. Immunochemistry
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 iso-
topes with short half-lives. We wanted something sim-
pler with the same sensitivity. Techniques for labeling
antibodies with enzymes had been described for im-
munohistochemistry (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
product system, namely alkaline phosphatase. Third,
we used the procedure of a standard RIA, i.e., a com-
petitive assay in which labeled antigen competed with
antigen in the sample for binding to antibodies co-
valently coupled to cellulose particles. Separation of
repeated centrifugation and washing. We had the first
ELISA calibration curve in early 1970. As usual, it took
a while to find a journal willing to publish the result.
We were continually asked why anyone would want to
be a proof-of-concept assay. Nevertheless, most rejec-
tions stated that the paper contained nothing new.
I think the very next developments were crucial in
use the technique of coating plastic with antigens or
antibodies to make a solid phase/immunosorbent (2).
ple. It is amazing how predictably and reproducibly
one can absorb a protein onto a polystyrene surface,
and how relatively durable the absorption is. The next
development was the introduction of microtiter plates
as the assay format(3). A standardized format allowed
the subsequent development of all sorts of gadgets for
the easy execution of assays in research and diagnostic
laboratories, including multichannel pipettes, washing
came monoclonal antibodies—a match for ELISA
made in heaven, particularly for sandwich assays for
measuring antigens (4). For many years, numerous
companies have sold a wide variety of antibodies,
enzyme-labeled reagents, coated 8-well strips, and kits
to facilitate research in many areas.
in my own laboratory for all sorts of applications (5),
but I was not involved in further assay development. It
has been very rewarding to watch from the sidelines
how the ELISA has been used in numerous important
diagnostic tests and how it has created a multibillion-
dollar industry. My favorite ELISAs are the quick and
easy ones that cannot be done any other way. For ex-
performed over 7 million tests for HIV in developing
countries with an extremely simple kit (Abbott Deter-
mine), manufactured and donated by Abbott Labora-
tories. The main goal is to identify pregnant women
infected with HIV to prevent mother-to-child trans-
mission during delivery. Animal health is another area
in which the ELISA has been and still is important. A
leading diagnostic company in the area of animal dis-
eases (IDEXX Laboratories), with billions of dollars in
diseases in dogs and cats; a large portion of that is in
simple and fast ELISAs.
After all this time, it is surprising that ELISA has
the PCR, chemiluminescence, or something else. The
reason? Few assay systems are as simple as the ELISA
ment. There is beauty in simplicity.
the intellectual content of this paper and have met the following 3 re-
quirements: (a) significant contributions to the conception and design,
acquisition of data, or analysis and interpretation of data; (b) drafting
or revising the article for intellectual content; and (c) final approval of
the published article.
Authors’ Disclosures of Potential Conflicts of Interest: No authors
declared any potential conflicts of interest.
1The Burnham Institute, La Jolla, CA.
2This paper has been cited more than 2150 times since publication.
* Address correspondence to the author at: The Burnham Institute, 10901 North
Torrey Pines Rd., La Jolla, CA 92037. E-mail firstname.lastname@example.org.
Received August 31, 2009; accepted September 17, 2009.
Previously published online at DOI: 10.1373/clinchem.2009.127803
Clinical Chemistry 56:2
Role of Sponsor: The funding organizations played no role in the
of data, or preparation or approval of manuscript.
1. Avrameas S. Coupling of enzymes to proteins with glutaraldehyde. Use of the
conjugates for the detection of antigens and antibodies. Immunochemistry
2. Engvall E, Jonsson K, Perlmann P. Enzyme-linked immunosorbent assay,
ELISA. II. Quantitative assay of protein antigen, immunoglobulin G, by means
of enzyme-labeled antigen and antibody-coated tubes. Biochim Biophys Acta
3. Voller A, Huldt G, Thors C, Engvall E. New serological test for malaria
antibodies. Br Med J 1975;1:659–61.
4. Uotila M, Ruoslahti E, Engvall E. Two-site sandwich enzyme immunoassay
with monoclonal antibodies to human alpha-fetoprotein. J Immunol Methods
5. Engvall E, Ruoslahti E. Binding of soluble form of fibroblast surface protein,
fibronectin, to collagen. Int J Cancer 1977;20:1–5.
Clinical Chemistry 56:2 (2010)