Monoclonal Antibodies to Hepatitis B Surface Antigen

We have established stable clones of murine somatic cell hybrids that produce high affinity monoclonal antibodies to hepatitis B surface antigen (HBsAg)1. Characterization of several of these antibodies has indicated that they bind to a 49000 dalton protein, likely encoded in the hepatitis B virus genome. One of these antibodies, designated 5D3 is an IgM antibody which binds to HBsAg with a KASN = 4 × 1011 liters/mole. This antibody, which has broad reactivity amongHHBsAg serotypes, can be used in an immunoradiometric assay. This assay has proven useful in evaluating clinical samples immunodiagnostically. Further studies with these unique monoclonal reagents should provide clinicians and research investigators with important new information about the hepatitis B virus.