Hepatitis B Surface Antigen Test - Hepatitis B Surface Antigen (HBsAg) Test

An immunoassay (enzyme-linked immunosorbent assay - ELISA) is used for the qualitative detection of hepatitis B virus surface antigen (HBsAg) in serum or blood plasma. The presence of HBsAg is a primary diagnostic marker for hepatitis B virus (HBV) infection, whether acute or chronic, indicating active viral replication in the liver.