Overfladeantigenet af HBV (HBsAg) er fremstillet v. h. a. dyrkning af gensplejsede gærceller (Saccharomyces cerevisiae), som bærer genet, der koder for det vigtigste overfladeantigen af HBV.
The surface antigen of the HBV (HBsAg) is produced by culture of genetically-engineered yeast cells (Saccharomyces cerevisiae) which carry the gene coding for the major surface antigen of the HBV.