High-performance ion-exchange chromatography of oligoribonucleotides using linear and hyperbolic salt gradients

A method for separation and chain length determination of oligo- and polynucleotides by high-performance anion-exchange chromatography was developed, which allows resolution of individual fragments according to their chain length n, up to n approximately 10 by linear gradient of sodium chloride and up to n approximately 30 by an hyperbolic gradient of this salt. The hyperbolic relationship between n and the salt concentration at which elution of the fragment occurs allows determination of the degree of polymerization of oligo- and polynucleotides with unknown n. The method proposed can be used for estimation of the effective charge of nucleic acids with complex structure.