[A new approach to the problem of immobilizing oligonucleotides on carboxyl-containing nylon membranes for nucleic acid hybridization].

: A simple and efficient method of the covalent immobilization of oligonucleotides on carboxyl-containing nylon membranes was proposed. The method is based on the reaction between a postsynthetically introduced aminoalkyl group of an oligonucleotide and membrane carboxyl catalyzed by a water soluble N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide. Judging from the mechanism of carboxyl group activation by the carbodiimide, optimal conditions of the immobilization were selected, which made it possible to increase the immobilization efficiency and carrier capacity as compared with those described previously. Using a 23-unit membrane-immobilized oligonucleotide as an example, the oligonucleotides immobilized were shown to be capable of hybridizing with complementary sequences.