title: Hepatitis B surface antigen (HBs Ag): tryptophan content and biological activity.
mesh_terms: D001966:Bromine; D006511:Hepatitis B Antigens / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D011863:Radioimmunoassay; D013053:Spectrophotometry; D013388:Succinimides / Q000031:analogs & derivatives; D014364:Tryptophan / Q000032:analysis*; D014443:Tyrosine / Q000032:analysis; D014508:Urea; D014764:Viral Proteins / Q000032:analysis
chemical_list: D006511:Hepatitis B Antigens; D013388:Succinimides; D014764:Viral Proteins; D014443:Tyrosine; D014364:Tryptophan; D014508:Urea; D001966:Bromine