[New method for studying the kinetics of the excision repair of DNA damages in mammalian cells].

A technique has been elaborated for analyzing the kinetics of excision repair of DNA. Previously it has been shown that inhibitors of DNA synthesis (1-beta-arabinofuranosylcytosine and hydroxyurea), taken together, drastically sensibilize human cells to the killing effects of DNA damaging agents. This sensibilization was found to depend on the ability of the cells to excision repair. If the time between the action of damaging factors and the incubation of cells in the mixture of inhibitors is extended, the rate of cell death is seen diminishing, because part of the primary damages is repaired. The dependence of residual damages on the time interval between the moment of damaging and the treatment by inhibitors reflects the kinetics of repair of DNA damages in cells. This method can be used for studying preparation at very low doses of damaging agent and even of spontaneous damages.