Nuclear immunostaining of hepatitis C infected hepatocytes with monoclonal antibodies to C100-3 nonstructural protein. Comparison of immunogold silver staining with other immunohistochemical methods.

Immunohistochemical methods have been used to localize an HCV antigen on paraffin embedded liver tissue sections by means of monoclonal antibodies to C100-3 nonstructural protein. Peroxidase-antiperoxidase, alkaline phosphatase-antialkaline phosphatase, biotin-streptavidin-peroxidase and immunogold silver staining methods showed a nuclear staining of the hepatocytes in cases of chronic hepatitis with positive HCV serology, alcoholic liver disease and hepatocarcinoma. No cross reactions were observed with viral hepatitis B and delta antigens. The strongest reaction without background staining was obtained with immunogold silver staining. Nuclear localization was compared to the cytoplasmic staining described in the literature.