PERFORMANCE OF UNCOATED AND COATED CAPILLARIES IN FREE ZONE ELECTROPHORESIS AND ISOELECTRIC-FOCUSING OF PROTEINS

Separation of standard proteins was compared in uncoated fused silica capillaries and in capillaries coated with a linear polymer covalently attached to the capillary wall. Performance of coated versus uncoated capillaries was assessed for free zone separations and capillary isoelectric focusing. In free zone separations performed under acidic conditions, separation profiles and run-to-run reproducibility were comparable, although resolution was poor in both cases. In free zone separations performed under basic conditions, separation profiles and reproducibility were clearly improved using coated capillaries. Use of coated capillaries was essential for obtaining useful results in isoelectric focusing.