SIMULTANEOUS MONITORING OF DNA FRAGMENTS SEPARATED BY ELECTROPHORESIS IN A MULTIPLEXED ARRAY OF 100 CAPILLARIES

Various excitation schemes for distributing a laser beam to a large number of capillaries in an array are evaluated. This led to the construction of a multiplexed system for monitoring the electrophoresis of DNA fragments in 100 capillaries. The laser excited fluorescence signals from each capillary are simultaneously recorded at the rate of 0.6 frame/s by a CCD camera. The reconstructed electropherograms show excellent reproducibility and minimal cross-talk. The system provides for two simultaneous excitation wavelengths so that it can be adapted for two-color, two-intensity DNA sequencing based on the commercial four-dye chemistry. Only 20 mW per laser line was employed. Further development of this system to accommodate up to 4096 independent sequencing channels at a time is discussed.