What is the ELISA test?

ELISA stands for enzyme-linked immunosorbent assay. It is a test used to determine if an individual has generated antibodies for a certain pathogen. In the test, inactivated antigens (for the pathogen) are coated onto a plate. In addition to antibodies from the patient serum, there is a second antihuman antibody linked to an enzyme. If the patient's antibodies bind to both the second antibody and the antigen, a color change occurs.