[Inhibition of chromatin autolysis in the process of isolating and incubating rat liver cell nuclei].

Dependence of endogenous nuclear nuclease/nucleases/ activity on pH value and ion composition of the isolation and incubation media was studied. Change in buffer pH value up to pH 9.0 and addition of Ca2+ instead of Mg2+ significantly inhibited the endogenous nuclease activity in rat liver nuclei. On the basis of these data the procedure for isolation of nuclei developed by Shaveau was modified. Almost complete inhibition of the endogenous nuclease activity was achieved during destruction of chromatin DNA from the isolated nuclei in presence of exogenous nuclease/micrococcal/.