CAPILLARY ELECTROPHORETIC SEPARATIONS OF BIOTECHNOLOGY-DERIVED PROTEINS IN ESCHERICHIA-COLI FERMENTATION BROTH

A capillary electrophoresis (CE) method was developed for the analysis of a recombinant DNA protein in a fermentation broth matrix. A polyac rylamide-coated capillary was employed to eliminate electroosmotic flo w, facilitating relatively rapid run times. Selectivity and efficiency were enhanced significantly through the incorporation of magnesium su lfate and acetonitrile, an organic modifier, into the separation buffe r. Both of these additives appeared to influence the separation by dim inishing the interaction of the protein analyte with the charged micel les present in the buffer. The quantitation capabilities of the CE met hod were validated and found to be comparable to the standards set by chromatographic techniques previously developed for similar applicatio ns.