Evidence for the multiplication of hepatitis B virus in "oval cell" culture originated from human embryonic liver.

Growth conditions fof human oval cells (immature hepatocytes),evidence of hepatitis B (HB) antigen synthesis in oval cells as revealed by immunofluorescent staining and successful passage of such an agent in the culture fluid up to the 4th passage are described. The results have been proved to be readily reproducible with different inocula. The oval cells used in these experiments were defined as small round cells, with scant cytoplasm, vesicular nuclei and small nucleoli, vitally stained with indocyanine green and synthesizing alpha-foetoprotein but no albumin.