IMMUNOASSAY
The purpose of an immunoassay is to measure (or, in a qualitative assay, to detect) an analyte. Immunoassay is the method of choice for measuring analytes normally present at very low concentrations that cannot be determined accurately by other less expensive tests. Common uses include measurement of drugs, hormones, specific proteins, tumor markers, and markers of cardiac injury. Qualitative immunoassays are often used to detect antigens on infectious agents and antibodies that the body produces to fight them.
