[Electron microscopic study of mammalian somatic cell fusion under the action of polyethylene glycol].

An electron microscope study of heterokaryons and synkaryons, obtained after the treatment of suspension of human embryonic fibroblasts and cultured fibroblasts of Chinese hamster (clone M151) with polyethylene glycol (PEC, m. v. 6000) has shown that in 15 minutes after the administration of PEG, the cell agglutination and disappearance of plasma membranes between cells takes place. It is not obvious, however, how PER is passing through the cell envelope, but the similar action of PEF towards the inner cell membranes was observed. In the heterokaryons, the nuclear fusion may occur not only during mitosis but also in interphasic cells. Therefore heterokaryons transform to synkaryons extremely synchroneously. During 20 hours the majority, and during 48 hours all the heterokaryons are seen transformed to synkaryons.