Radioimmunoassay:
Radioimmunoassay (RIA) developed by Rosalyn Yalow and Soloman Berson (1958) is an extensively used popular technique for assaying biologically important substances such as hormones, vitamins, drugs, virus, etc. in extremely small amounts of body fluids such as blood. For this unique discovery Dr Rosalyn Yalow was awarded Nobel Prize in Medicine in 1977 where insulin was determined using 131I as tracer. RIA is an extensively used technique in medical diagnostic laboratories worldwide for the determination of hormones (B, TA, TSH, etc.), drugs, viruses, and other organic species.