HBsAg Antibody / Hepatitis B surface antigen

Hepatitis B surface antigen (HBsAg) is a glycoprotein on the surface of hepatitis B virus. After hepatitis B infection, HBsAg appears as the first viral marker. HBsAg can be detected in blood, saliva, breast milk, sweat, tears, nasopharyngeal secretions, semen and vaginal secretions of patients 2 to 6 months after infection with HBV. HBsAg antibodies are mainly used for the diagnosis of hepatitis B virus.