Micellar electrokinetic capillary chromatography of proteins

Separations of model proteins obtained under denaturing conditions in the presence of micellar concentrations of ionic surfactants displayed high resolution and efficiency using either bare silica or C18-derivatized silica capillaries. Superior migration time reproducibility was achieved through the use of the C18-derivatized capillaries (run-to-run migration time % RSD = 0.2), relative to that obtained in bare silica capillaries (run-to-run migration time % RSD = 2.2), in the absence of buffer replenishment. The effects of surfactant concentration and pH upon the separation of a mixture of five model proteins of varying ionic and hydrophobic character were investigated, and the application of this technique to the analysis of a recombinant DNA-derived protein in fermentation broth was demonstrated.