to compare the sensitivity of transcriptionally active and inactive genes on chromatin toward dna-damaging agents , we treated normal human fibroblasts ( wi-38 ) cells in n-methyl-n'-nitro-n-nitrosoguanidine ( mnng ) , x-ray , 4-hydroxyaminoquinoline 1-oxide or n-acetoxy-2-acetylaminofluorene , and high molecular weight dna was isolated .
C0008546
chromatin
C0007634
cells