Methods for detection of hepatitis B surface antigen in paraffin sections of liver: a guideline for their use.

Methods for the localisation of hepatitis B surface antigen (HBsAg) in paraffin sections of the liver include the detection of ground-glass hepatocytes and the use of Shikata's orcein stain, and of immunoperoxidase and immunofluorescent techniques. A comparative study of the different methods on 20 livers shows the orcein stain to be the method of choice for routine use. The Shikata stain is not only specific but is relatively inexpensive, easily performed, and stains out distinct cytoplasmic inclusions even in stored formalin-fixed livers, old paraffin blocks, and autolysed livers. Since HBsAg is irregularly distributed in the liver, adequate sampling is necessary to prevent false negative; when sufficient tissue is available at least five blocks should be examined before a case is labelled as HBsAg-negative.