HIGH-PERFORMANCE CAPILLARY ELECTROPHORESIS FOR IN-PROCESS CONTROL IN THE PRODUCTION OF ANTITHROMBIN-III AND HUMAN CLOTTING FACTOR-IX

Antithrombin III (ATIII) and factor IX (FIX), two proteins from the cl otting cascade, were investigated in parallel experiments, using capil lary gel electrophoresis and capillary isoelectric focusing. The resul ts from these experiments were compared with the results obtained from sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and slab gel isoelectric focusing. In the case of ATIII, capillary gel sieving showed comparable results to SDS-PAGE with the added advantag e of the shorter time required for analysis. By optimizing capillary i soelectric focusing (cLEF), a separation of the ATIII isoforms was ach ieved. In the case of FIX, capillary gel electrophoresis (SDS-CE) of a FIX: preparation gave similar results to those obtained by size-exclu sion high-performance liquid chromatography and SDS-PAGE, but turned o ut to be less sensitive in detecting protein impurities at low concent rations. The microheterogeneity of this protein was shown by using cIE F. (C) 1998 Elsevier Science B.V.