Radioimmunoassay (RIA) is a sensitive and quantitative method used to measure the concentration of antigens in vitro. Nanomolar and picomolar concentrations of hormones in biological fluids can be detected by RIA. It is the first immunoassay technique to analyze small amounts of analyte. This assay is highly sensitive and can quantify tiny amounts of analyte level with the help of antibodies. The increasing usage of RIA in biopharmaceutical industries has led to an increased demand of this technique. Pronalyse with experienced staffs provides RIA for pharmacokinetics analysis to ensure quality and safety.