DNA AND Effects of Radiation and Peroxides 279 



(in order to eliminate the peroxide) and then plated on 

 nutrient agar for colony counts. All survival curves were of 

 the multiple-hit type (Fig. 1). The results can be summarized 

 as follows: 



(1) Sensitivity to peroxide varies as sensitivity to radiation. 



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Fig. 2. Inactivation of (1) growing and (2) resting Esch. 

 coll K12S by cumene hydroperoxide. 



All bacteria are more sensitive in the growing than in the 

 resting stage (Fig. 2). If one compares several strains, one 

 finds not only the same order of increasing sensitivity to 

 peroxide and to radiation (B/r -> K12 -> B), but even the same 



