Abstract: An instrument for capillary electrophoresis has a vertically translatable carrier holding one end of the capillary and an electrode connected to a power supply, and a rotary carousel for presenting containers of sample and buffer solutions to a load position where the end of the capillary and the electrode may be inserted by operating the carrier. The other end of the capillary and a second electrode connected to the power supply are immersed in an outlet buffer reservoir. The instrument has a vacuum supply for providing a relative vacuum over the solution in the outlet buffer reservoir, so simple material may be injected into the capillary either by electromigration or by differential pressure. After injection, the first end of the capillary and the electrode may be immersed in buffer to accomplish electrophoresis. By manipulating the carousel and carrier, multiple samples may be electrophoresed in series.