Method for ph-biased isoelectric trapping separations

摘要

A method for separating an ampholytic component by electrophoresis, the method involving placing a sample containing an ampholytic component having a pI value in an electrophoresis separation system comprising an anolyte having a pH and a catholyte having a pH, the catholyte pH being higher than the anolyte pH, one or more ion-permeable barriers disposed between the anolyte and catholyte wherein at least one of the barriers is an isoelectric barrier having a pI value which is higher than the anolyte pH and lower than the catholyte pH; providing an isoelectric buffer having a pI value higher than the pH of the anolyte and lower than the pH of the catholyte and different from the pI value of the ampholytic sample component and different from the pI value of an ion-permeable isoelectric barrier; and exposing the sample to an electric potential so as to trap the ampholytic sample component in a non-isoelectric state in the presence of the isoelectric buffer in the electrophoresis system.