Capillary electrophoresis (CE) is a powerful analytical separation technique that brings speed, quantitation, reproducibility and automation to the inherently highly resolving but typically labor intensive methods of electrophoresis (e.g., Capillary Electrophoresis Theory and Practice, Grossman and Colburn, eds., Academic Press (1992)). While early capillary electrophoresis systems utilized only a single capillary tube, multi-capillary systems have been developed to provide increased throughput (e.g., Mathies et al., U.S. Pat. No. 5,247,240; Dovichi and Zhang, U.S. Pat. No. 5,439,578; Kambara, U.S. Pat. No. 5,516,406; Takahashi, et al., Anal. Chem., 66: 1021-1026 (1994)). Such multi-capillary CE systems are particularly attractive for use in large scale DNA sequencing projects.
However, existing multi-channel capillary electrophoresis systems have several significant shortcomings that limit their utility, particularly for applications requiring a high degree of automation, throughput, detection sensitivity and reliability. For example, existing systems do not provide for a sheath-flow detection cuvette wherein a capillary array may be replaced by a user without extensive disassembly of the cuvette. In addition, existing systems do not provide for a sheath-flow detection cuvette wherein fresh separation media and/or capillary wash solutions may be introduced into outlets of the capillary tubes under high pressure. Thus, there remains a continuing need for an automated multi-channel capillary electrophoresis device including these features.