Abstract
The cell multiplication inhibitory effect of SDS‐treated mouse interferon separated into antiviral (AV) and cell multiplication inhibitory (CMI) fractions was compared to that of untreated similar interferon on a line of murine osteosarcoma cells. The untreated interferon preparation and the CMI fractions dose‐dependently inhibited the multiplication of the cells as measured by cell count and incorporation of 3H‐thymidine into the cultures. The AV fractions, containing comparable antiviral activites as the untreated interferon preparations, had only a minor effect on cell multiplication. The biochemical properties of the fractions studied remain unknown.