SEPARATION MECHANISM OF PULLULAN SOLUTION-FILLED CAPILLARY ELECTROPHORESIS OF SODIUM DODECYL SULFATE-PROTEINS

The separation mechanism of capillary electrophoresis of sodium dodecy l sulfate (SDS)-proteins using pullulan with a molecular mass range of 50 000-100 000 as a separation matrix was investigated. The pullulan solution was filled into fused-silica capillaries whose inner walls we re coated with linear polyacrylamide through chemically stable Si-C li nkages. Baseline separations of SDS proteins were achieved at concentr ations ranging from 3-10% w/v of pullulan. The entanglement threshold of pullulan solution was found to be around 0.5% w/v, Indicating migra tion of SDS-proteins through an entangled pullulan network. Ferguson p lots exhibited a linear relationship between log mobility and pullulan concentration, Linear relationships were also obtained for double log arithmic plots of the electrophoretic mobility and protein molecular m ass, These results show that the separation is based on mass discrimin ation in accordance with the Ogston theory.