Reassociation kinetics of DNA from x-irradiated ascites hepatoma cells of the rat.

The kinetics of the reassociation fo DNA from ascites hepatoma cells has been studied. The curve exhibited three zones corresponding to 'fast', 'intermediate' and 'slow' speeds of DNA reassociation. The difference was observed in the DNA reassociation curves of the control and irradiated (1500 rad) cells which was particularly expressed in the 'slow' zone (10(2) less than C0t less than 10(4). The same dose, however, does not qualitatively effect the secondary DNA structure, which was estimated by the method of thermal elution from the hydroxyapatite column.