What is the definition of "ELISA"?

An enzyme-linked immunoassay (ELISA) is a test that detects antibodies in the blood. According to the University of Maryland Medical Center, this test is used to find out whether a patient has been exposed to a particular type of virus or other infectious agent.

An ELISA test can detect both current and past infections. As well as antibodies, an ELISA test can also be used to detect antigens (substances that provoke an immune response, such as bacteria or proteins) or enzymes. The test is performed by taking a blood sample from the patient and sending it to a laboratory for analysis.