Hepatitis B surface antigen (HBsAg) testing is important for the detection of hepatitis B virus (HBV) infection. Published studies suggest good performance among commercially available automated HBsAg assays but also highlight clinically relevant differences. These differences include sensitivity and the ability to detect both wild-type and mutant HBV strains. Comparative studies important to the clinical use of the HBsAg assay are reviewed and discussed.
