Аннотация:Complex formation in mixtures of DNA, sodium polyacrylate, and 3,3-ionene was studied, and constants of polycation binding with each of the competing polyanions per mole of monomer units (K1) and per mole of the reacted ionene chains (Kn) were determined. It was demonstrated that an essential change in the ratio of Kn constants results from an insignificant variation in K1 values. It was shown that, with an increase in the degree of polymerization of sodium polyacrylate, the predominant binding of ionene with DNA disappears and the interaction of ionene with polyacrylate becomes preferential. As the concentration of sodium chloride added to the system grows, the tendency toward complexation of ionene chains with DNA enhances.