Abstract: A method of separating charged molecules having different numbers of charges thereon includes the step of passing the molecules to be separated through ion-exchange material such as an ion-exchange chromatograpy column in normal manner so that molecules to be separated bind to the ion-exchange material. Displacer molecules are then passed through the ion-exchange column to selectively release certain of the molecules to be separated from the ion-exchange material, while others of the molecules to be separated remain bound to the material.

Abstract: A process is disclosed in which high purity protamine-DNA complexes are prepared by collecting nucleoprotamines specific developmental stages of a life form, specifically, amphibian, egg by low temperature processing. The process also includes the steps of sequential homogenization in a high concentration aqueous salt solution at a buffered low pH, followed by ultracentrifugation to remove insoluble matter. Either a crude mixture or pure isolate of the complexes may be produced. Pure isolates require aqueous chloroform extraction to isolate protein and to remove lipids. Lyophilization then removes chloroform and excess water. The isolate is then fractionated by single pass alumina chromatography. Dialysis against pure water removes salts. Repeated lyophilization removes excess water and concentrates single protamines and protamine-like proteins. The mixture may then be reconstituted with 5% weight/volume heterologous or homologous DNA, in order to shield from charge toxicity.