The potential clinical diagnostic utility of capillary electrophoresis in an open-tubular column is established. Separation patterns for serum proteins by conventional agarose gel electrophoresis can be faithfully reproduced by a capillary electrophoresis procedure that provides the complete run data in 8 min. Hemoglobin variants can be separated within 10 min. The capillary electrophoresis separations are performed reliably and reproducibly in an untreated 75 micron (i.d.) x 25 cm fused-silica column. Diluted serum or hemoglobin samples can be loaded on an automated instrument with on-line injection, detection, and quantification, providing a truly "walkaway" electrophoresis system.