[en] To establish radioimmunological procedures in order to detect the surface antigen (HBsAg) and the surface antibody (anti-HBs) of viral hepatitis B. Iodine-125 was incorporated into the antigen or monoclonal antibody with the employment of the Chloramine T method. Theoretical and experimental yield of labeling and specific activities were calculated for labeled molecules. In order to obtain the solid phase component, the surface antigen or surface antibody maintained in a buffer solution of carbonate-bicarbonate and posterior incubation with newborn calf serum at 10 percent, was coated to polystyrene beads. International reference standards and internal negative and positive quality control samples were employed during radioimmunoassays