Complementary addressed modification of double‐stranded DNA within a ternary complex

Abstract
Double‐stranded DNA containing a d(pG)18·d(pC)18 sequence was shown to be selectively alkylated in the vicinity of this fragment using the 5′‐p‐(N‐2‐chloroethyl‐N‐methylamino)benzylamide of deoxyribooligocytidylate, CIRCH2NH(pdC) n (n = 9, 15), in conditions favouring triple‐stranded complex formation.