Immunoassay is a term frequently used in the field of laboratory science and immunology. It is a technique used to measure the concentration of antibody in a given sample. Immunoassay is also known as enzyme immunoassay or EIA, enzyme-linked immunosorbent assay or ELISA, and radioimmunoassay or RIA. Other synonyms for immunoassay include fluorescence immunoassay or FIA, chemiluminescent immunoassay or CLIA, and magnetic immunoassay or MIA. These techniques are extensively utilized in medical diagnostics, biotechnology, and pharmaceuticals. The development and evolution of immunoassay technology have revolutionized the field of diagnostics, enabling accurate detection and quantification of various analytes in biological samples.