DNA fragments in Friend erythroleukemia cells induced by dimethyl sulfoxide.

The idea of the correlation between DNA damage caused by dimethyl sulfoxide (Me2SO) and the induction of erythrodifferentiation in murine erythroleukemia (MEL) cells needs reevaluation as a result of the hydroxyapatite chromatographic analysis of DNA from Me2SO-treated and untreated cells as a function of the time in culture. Because Me2SO causes an arrest in G1 phase and consequent delay in DNA synthesis, the valid comparison would be of the DNA samples taken from control and induced cells at the same stage of growth rather than at the same time in culture. At the same stage of growth, there is no evidence of the induction of DNA damage by Me2SO. Presumably, so-called degradation reported in the past stemmed from the fragments of DNA replication.