Capillary electrophoretic separations of proteins using carrier ampholytes.

Capillary separations of proteins using carrier ampholytes are performed between an anolyte and a catholyte of same pH (pH 3). Depending upon the concentration of carrier ampholytes used, two different separation processes take place. At a 10% concentration, the high-resolution separation of six model proteins is achieved, which can be described as a transient capillary isoelectric focusing (cIEF) system moving isotachophoretically. The isotachophoretic (ITP) behaviour of the system is evidenced by the influence of the catholyte concentration on the separation. The separation is neither pure cIEF nor pure cITP and the migration order of the proteins results from the influence of both their isolelectric points and their mobilities.