Australia antigen present in which part of HBV:

Ans. A. Envelopea. The discovery of HBV was serendipitous. In 1965, Blumberg, studying human serum lipoprotein allotypes, observed in the serum of an Australian aborigine a new antigen which gave clearly defined line of precipitin with sera from two hemophiliacs who had received multiple blood transfusions.b. This was named Australia antigen. By 1968 it was found to be associated with serum hepatitis.c. It was subsequently found to be the surface protein of HBV embedded in the envelope. Hence the name of Australia antigen was changed to hepatitis B surface antigen.