[Chemical reactions in double-stranded nucleic acids. IV. Cyanogen bromide--a highly effective reagent in the condensation of oligodeoxyribonucleotides].

Cyanogen bromide was found to induce a smooth and highly efficient condensation of oligonucleotide blocks within DNA duplexes. This template-directed reaction proceeds in the aqueous solution at 0 degree C for 1-2 min. Cyanogen bromide catalyzes the formation not only of phosphodiester, but also of unnatural phosphoramide and pyrophosphate interoligomer bonds.