RADIATION ACTION ON DNA IN BACTERIA: EFFECT OF OXYGEN.

In Escherichia coli cells ionizing radiation produces a degradation of DNA to approximately 50 percent of the total amount originally insoluble in trichloroacetic acid. There is also a reduction of synthesis. Oxygen inhibits the degradation process by a dose reduction factor of 4 and the synthesis process by a factor of approximately 1.5. Thus, at relatively low doses, radiation action on bacteria is very probably mediated through the DNA.