Abstract
Polyribocytidylate-(3)H-polyriboinosinate (rC-(3)H:rI) enters cultured rabbit kidney cells from the surrounding medium within (1/2) hr after exposure. Grains are found in the cytoplasm, nucleus, and nucleolus. At 2 hr, grains are localized predominantly over the nucleolar regions. Subsequently, the grains in the nucleus become dispersed. A specific receptor site for the initiation of interferon production was not revealed.