Capillary gel electrophoresis for DNA sequencing. Laser-induced fluorescence detection with the sheath flow cuvette

Capillary polyacrylamide gel electrophoresis separation of dideoxycytidine chain-terminated DNA fragments is reported. A post-column laser-induced fluorescence detector based on the sheath flow cuvette was used to minimize background signals due to light scatter from the gel and capillary. A preliminary mass detection limit of 10(-20) mol of fluorescein-labeled DNA fragments was obtained. The system was used to analyze an actual DNA sequencing sample. Theoretical plate counts of 2 x 10(6) were produced. Gel stability limits the performance of the current system.