High-speed DNA genotyping using microfabricated capillary array electrophoresis chips

Capillary array electrophoresis (CAE) chips have been designed and fabricated with the capacity to rapidly (< 160 s) analyze 12 different samples in parallel. Detection of all lanes with 0.3 s temporal resolution was achieved using a laser-excited confocal-fluorescence scanner. The operation and capabilities of these CAE microdevices were first determined by performing electrophoretic separations of pBR322 MspI DNA samples. Genotyping of HLA-H, a candidate gene for the diagnosis of hereditary hemochromatosis, was then performed to demonstrate the rapid analysis of biologically relevant samples. Two-color multiplex fluorescence detection of HLA-H genotypes was accomplished by prelabeling the standard pBR322 MspI DNA ladder with a red emitting bis-intercalation dye (butyl TOTIN) and on-column labeling of the HLA-H DNA with thiazole orange. This work establishes the feasibility of using CAE chips for high speed, high-throughput genotyping.