Fast high-throughput screening of glutathione S-transferase polymorphism by voltage programming-based multi-channel microchip electrophoresis.

Glutathione S-transferase (GST) polymorphism (M1 = 215 bp and T1 = 480 bp) can cause liver damage and increase the risk of cancer. In this study, voltage programming (VP)-based microchip electrophoresis (ME) with a laser-induced fluorescence (LIF) detector was developed to detect specific sizes of DNA fragments. The optimum conditions for a single-channel microchip were as follows: 4 kV for 0-9.5 s, 1.5 kV for 9.5-15.5 s, and 4 kV for 15.5-30 s. Next, these conditions were applied to another microchip that was constructed with many channels making possible simultaneous parallel detection. Finally, GST genes extracted from human blood were amplified by polymerase chain reaction (PCR) and were introduced into the multi-channel microchip. Target DNA molecules amplified by only 10 PCR cycles could be detected by the VP-based multi-channel ME method, but not by slab gel electrophoresis (SGE). In addition, the migration time for ME was <15 s, which was 700 times faster than conventional SGE. The developed VP-based multi-channel ME method with LIF detection was demonstrated to be an effective, rapid analysis technique for highly sensitive and high-throughput screening of GST genes.