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What is ELISA?
ELISA is an abbreviation for "enzyme-linked immunosorbent assay."
What is an ELISA test?
An ELISA test uses components of the immune system and chemicals for the detection of immune responses in the body (for example, to infectious microbes). The ELISA test involves an enzyme (a protein that catalyzes a biochemical reaction). It also involves an antibody or antigen (immunologic molecules). Examples of the uses of an ELISA test includes to diagnose infections such as HIV (human immunodeficiency virus) and some allergic diseases.
What is the use of an ELISA test?
ELISA tests are primarily used for the detection of proteins (as opposed to small molecules and ions such as glucose and potassium). The substances detected by ELISA tests can include hormones, bacterial antigens, and antibodies that the body has made in response to infection or vaccination.
How does ELISA testing work?
There are variations of the ELISA test, but the most basic type consists of an antibody attached to a solid surface. This antibody has affinity for (will latch on to) the substance of interest, such as a hormone, bacteria, or another antibody. For example, human chorionic gonadotropin (HCG), the commonly measured protein which indicates pregnancy, can be detected by ELISA. A mixture of purified HCG linked to an enzyme and the test sample (blood or urine) are added to the test system. If no HCG is present in the test sample, then only HCG with linked enzyme will bind to the solid surface. The more HCG that is present in the test sample, the less enzyme linked HCG will bind to the solid surface. The substance on which the enzyme acts is then added and the amount of product is measured in some way, such as a change in color of the solution.
What are the advantages of ELISA testing?
ELISA tests are generally accurate tests. They are considered highly sensitive and specific (accurate) and compare favorably with other methods used for the detection of substances in the body. The ELISA testing method is more straightforward and easier to perform than older laboratory techniques, which often required radioactive materials.
"Function and clinical applications of immunoglobulins"