since strand breakage of dna in intact cells may occur secondary to activation of dna-dependent nucleases during repair replication , cscl gradient density sedimentation was utilized to examine whether repair processes were induced by exposure of cells to nicl2 , hgcl2 and cacro4 . cacro4 and nicl2 induced substantial dna-repair activity at concentrations and exposure times where dna lesions could not be detected whereas hgcl2 induced a 10-fold lower level of dna-repair activity compared to cacro4 at optimal concentrations which again were below the concentrations of this metal that produced measurable dna lesions .
C0598312
replication
C0012854
dna