HIGH-PERFORMANCE CAPILLARY ELECTROPHORESIS OF PROTEINS - SODIUM DODECYL-SULFATE POLYACRYLAMIDE GEL-FILLED CAPILLARY COLUMN FOR THE DETERMINATION OF RECOMBINANT BIOTECHNOLOGY-DERIVED PROTEINS

Fused-silica capillary columns were filled with sodium dodecyl sulfate-polyacrylamide gel and the column effluent was monitored at 214 nm using a commercially available high-performance capillary electrophoresis (HPCE) instrument to separate and rapidly quantify recombinant biotechnology-derived proteins. An excellent linear relationship (r > 0.999) exists between the peak migration time and the molecular weights of reference proteins in the range 10 000-100 000 and 40 000-200 000 dalton by use of the capillary columns filled with acrylamide gel at a T composition of 5% and 3%, respectively. The relative standard deviation (R.S.D.) of the peak migration time is ca. 1%. Theoretical plates of 5.10(5)-1.10(6) per metre are routinely being obtained. Calibration graphs of peak area versus weight of recombinant biotechnology-derived proteins are linear (r > 0.999) and the proteins may be quantified with an R.S.D. of ca. 3-7%. As little as 50 nmol of a protein may be quantified and an impurity peak of molecular weight ca. 1500 less than that of the parent compound (ca. 60 000 dalton) may be differentiated by HPCE with a gel-filled capillary column.