1.   The many different modes of transmission of hepatitis B are due to the fact that almost all body secretions have been shown to contain the infectious viral surface antigen.

2.   HBcAg was usually the first viral antigen to be detected by immunohistochemistry.

3.   Studies of the in vitro microcytotoxicity assays, however, have suggested hepatitis B virus capsid protein, rather than envelope protein, as a target viral antigen.

4.   The other test detects viral antigen, which is a part of the virus that induces the body to produce antibodies against it.