RELATIONSHIP BETWEEN THE Mason-Pfizer monkey virus and Hela virus: immunoelectron microscopy.

Envelope antigens of the Mason-Pfizer monkey virus (MPMV) and the morphologically similar HeLa virus, which is continuously produced in some HeLa cell lines, were compared by indirect immunoferritin techniques. Antisera raised against MPMV and HeLa virus revealed cross-reacting antigenic specificities on the surfaces of both agents, and cross-absorption and end-point dilution techniques indicated the presence of identical envelope antigens. The results demonstrated a close relationship, if not an identity, between MPMV and HeLa virus.