Use of alkylating derivatives of DNA for directed action on the genome

The proposed method of directed action on definite, previously selected sections of the genome involves the use of molecules of DNA complementary to these sections, bearing alkylating groups. N,N, N'-tri(β-chlorethyl)-N'-(n-formylphenyl) propylenediamine-1,3 joined to denatured DNA of phage T7. The alkylating derivative of the DNA was shown to be highly stable under conditions close to physiological: incubation at 21°C for 18 h at pH 7.5 or at 40°C for 4 h at pH 7.5 did not lead to marked elimination of the alkylating bases from the structure of the DNA. In a number of experiments it was established that DNA bearing alkylating groups are capable of highly specific interaction with the complementary polynucleotides; the alkylating derivative of the restriction fragment of the DNA of phage T7 maintains its ability to hydridize with phage T7 DNA complementary to it but does not hybridize with the non-complementary DA of chick erytrhocytes. The alkylating derivative of the restriction fragment of phage T7 DNA alkylates the complementary section of phage T7 DNA, forming a covalently linked complex, stable under denaturing conditions.