A protein connection assay is an analytic method to measure corticosteroids, cortisone, progesterone, testosterone and thyroxine.

(FIA) A fluorescent immunoassay (also called fluoroimmunoassay) is an analytic assay method based on a fluorescent-labeled antigen or antibody. Fluorescent measurements are usually more sensitive than spectrophotometric measurements. Therefore, FIA methods have greater analytical sensitivity than enzyme immunoassay techniques.

(ELISA) An enzyme linked immuno sorbent assay, also called ELISA, or enzyme immunoassay (EIA) is a diagnostic tool to measure the concentration of a particular molecule.

See also Radioimmunoassay.

Salomon Berson developed in 1959 (published in 1960) together with Rosalyn S. Yalow the radioimmunoassays.

See Radioimmunoassay.

(CPBA) The competitive protein binding analysis is a radioimmunoassay utilizing radioactive isotope labeled antigens, which compete with unlabeled antigens for chemical bond with specific antibodies. Binding proteins occur naturally and have affinity for other substances.