Biopolymers and cell. 1988. Volume 4. № 3. 124 - 128

V. G. Bezlepkin, R. A. Namvar, T. A. Bezlepkina, A. I. Gaziev

THE DNA POLYMERASE ACTIVITY AND FORMATION OF STRAND BREAKS IN DNA OF ZAJDELA ASCITES HEPATOMA CELLS PERMEABILIZED BY DIFFERENT METHODS

Summary

    Zajdela hepatoma cells were permeabilized for nucleotides by the treatment with digitonin, hypotonic buffer, Tween-80 or Triton X-100. The dependence of the DNA breakage amount and the level of [3H]TMP-incorporation into the cell DNA on the type of the used membrane damaging agent was shown when incubating the permeable cells in the DNA polymerase mixture. There is reason to believe that various agents providing permeability of cell wall produce a different effect on chromatin increasing availability of DNA for attacks of endogenous nucleases. The formed DNA breaks induce the unscheduled DNA synthesis and increase the total level of the DNA polymerase activity in permeable cells. Thus, to investigate the DNA repair on the permeable cells the methods of cell permeabilization providing the minimal initial level of chromatin damage should be used.