Increased efficiency of electrophoretic separations by mobility matching

Abstract

The invention concerns electrophoresis and methods and electrolyte compositions for decoupling or isolating the dual functions of the electrolyte composition in order to increase separation selectivity or reduce electromigration dispersion, or both. An electrolyte composition is used in electrophoresis to separate a charged analyte having a mobility μa in an electric field. The composition includes a buffer system having an ionic component that controls the pH of the composition and mobility matching ions having a mobility μ2 in the electric field, such that μa /μ2 equals about one. Alternatively, the buffer system may maintain the composition's pH and a complexing agent may complex with the buffer system to alter the mobility μ2 of an ionic component of the buffer system, such that μa /μ2 equals about one. The pH of the composition is within a pH range selected based on the analyte to be separated, and μ2 remains substantially constant over this pH range.