Development of Microfabricated Capillary Array Electrophoresis Chip and Direct Observation of Dynamics of DNA Molecules Migrating in Microchannels

We have examined the LIGA process for the microfabrication of capillary array electrophoresis (CAE) chip using synchrotron radiation lithography in polymethylmethacrylate (PMMA) substrates and developed novel type microfabricated CAE chip. Laser-induced fluorescence detection system for the CAE chip has been constructed by the modification of laser confocal fluorescence microscopy. DNA molecules labeled by intercalating fluorescent dye were detected during migrating in the array of microchannels and conformational dynamics of single DNA molecule in microchannels filled with linear polyacrylamide under electric field was observed by this system to elucidate the separation mechanism of DNA and to optimize the separation conditions for DNA analysis. Based on this observation, we demonstrated that linear polyacrylamide is suitable for the rapid separation of large DNA fragments less than 166 kbp by microfabricated CAE chip without pulsed electric field.