title: Letter: RIA for HBAg: utility and nomenclature.
mesh_terms: D001782:Blood Donors; D006509:Hepatitis B / Q000517:prevention & control; D006511:Hepatitis B Antigens / Q000032:analysis*; D006801:Humans; D011863:Radioimmunoassay; D009626:Terminology as Topic
chemical_list: D006511:Hepatitis B Antigens