HIGH-MOLECULAR-WEIGHT POLYARGININE AS A CAPILLARY COATING FOR SEPARATION OF CATIONIC PROTEINS BY CAPILLARY ELECTROPHORESIS

Fused silica capillaries treated with dilute solutions of high molecul ar weight polyarginine (PA) provide capillary electrophoresis separati on efficiencies of more than 2 million theoretical plates per meter an d improved migration time reproducibility for the analysis of protein mixtures. The non-covalently bound PA coating was stable for several d ays and could be easily regenerated by exposing the capillary to a dil ute solution of PA for several minutes. A comparison of PA and polybre ne (PB) treated capillaries indicates that the PA capillary is capable of providing higher separation efficiencies, but that PB provides a m ore stable coating when used under acidic conditions and with high ion ic strength buffers.