[Cytophotometric studies of DNA concentration and the interrelationship of different forms of chromatinin cells of different tissues].

Using cytophotometry, biochemistry, autoradiography and electron microscopy, the evidence was provided that in addition to a non-condensed form of chromatin the liver cell nuclei contain a condensed one which disappears from the nuclei when treated with a nuclear fraction of the liver homogenate. After degradation the DNA related to the condensed chromatin, an "unscheduled" DNA synthesis occurs. On the other hand, measurements that involve a single hydrolysis time only, were not shown to give a comprehensive picture of the DNA content or the state of chromatin. The analysis of the results obtained from hydrolysis curves suggests that in some cases the deviation from DNA constancy in the cell nuclei may be seen.