POTENTIAL OF ONLINE ISOTACHOPHORESIS-CAPILLARY ZONE ELECTROPHORESIS WITH HYDRODYNAMIC COUNTERFLOW IN THE ANALYSIS OF VARIOUS BASIC-PROTEINSAND RECOMBINANT HUMAN INTERLEUKIN-3

Isotachophoresis-capillary zone electrophoresis with hydrodynamic coun terflow was applied to the analysis of various basic model proteins an d recombinant human interleukin-3. The use of coated capillaries and s imple modifications of a commercial capillary zone electrophoresis (CZ E) system allowed the detection of concentrations in the 10(-8) M regi on. The limit of detection was decreased by a factor of 100 compared t o conventional CZE. The separation efficiency was unaffected by the pr eceding isotachophoretic step. Our method is applicable to the analysi s of proteins with an isoelectric point higher than 7.0.