STUDIES UTILIZING DISINTEGRATION 105 



other than phosphorus were used as the source of the disintegration. The 

 mechanism of suicide is only incompletely known. Using P 32 , when 

 single-stranded RNA and DNA viruses are labeled, it is understandable 

 that death will ensue because the nucleic acids are held together by a 

 phosphorus backbone which is broken by the recoil of the S 32 to which 

 the P 32 is transformed by the disintegration. For double-stranded DNA, 

 the efficiency of the suicide is much less (about 0.1 efficient) and is 

 probably due to the fraction of times there occurs a scission of the 

 opposite strand originating from the recoiling S 32 atom. 



