title: Letter: Varieties of HBAg.
mesh_terms: D002467:Cell Nucleus / Q000276:immunology; D003593:Cytoplasm / Q000276:immunology; D006506:Hepatitis A / Q000276:immunology; D006510:Hepatitis B Antibodies / Q000032:analysis; D006511:Hepatitis B Antigens / Q000302:isolation & purification*; D006801:Humans; D008099:Liver / Q000276:immunology
chemical_list: D006510:Hepatitis B Antibodies; D006511:Hepatitis B Antigens