[Several methodologic problems in the control of cell cultures].

Some human and animal continuous cell lines as well as primary cell cultures were examined by karyological, electron microscopial, virological and molecular biological methods and also by the electrophoretic motility of glucose-6-phosphate dehydrogenase (G-6-PDG) in polyacrylamide gel. All human and animal continuous cell lines were shown to contain mycoplasma, 17-to contain intracytoplasmic particles of type A oncornaviruses, 5 -- type B oncornaviruses similar to Mason-Pfizer virus, 8 -- paramyxoviruses, 2 --oncornaviruses type C. A high molecular RNA with sedimentation constant 64--70 S was found in oncornaviruses isolated from cell cultures. Intracellular virus or subviral structures were detected by association of the reverse transcriptase activity with high molecular RNA. The presence in the cell cultures of marker chromosomes of HeLa cells, the absence in these cultures of Y chromosomes, the presence of the G-6-PDG enzyme with type A motility indicate the possibility of contamination of human continuous cell lines with HeLa cells.