Multichannel microchip electrophoresis for genetic and molecular separation detection

Abstract

Summary form only received as follows: Multi-microchannel laser-induced fluorescence (LIF) detection of microchip-based electrophoretic separations are presented. While ultrafast laser beam scanning for LIF detection on capillary or microchannel arrays has been demonstrated with galvanometric scanning or a translating stage, it can also be accomplished using an acousto-optical deflector (AOD). AOD scanning differs from other approaches in that no moving parts are involved, and the laser beam can be addressed very fast to any position in the scanning range. For ultrafast multichannel electrophoresis, a microprocessor embedded system with a digital/analog converter (DAC) and an analog/digital converter (ADC) is employed. The system first outputs a linear increasing waveform from DAC to AOD to control the laser beam scanning across all the channels and to generate an addressing voltage array defining the position of the channels. During electrophoretic separation, the system provides addressing voltages to address the laser beam accurately to each channel on a microchip, and collect the fluorescence signal from ADC. With the ability to control the laser beam on the nanosecond timescale, scanning rates depend only on the digital-to-analog conversion and data collecting time, which is up to 1 kHz. In addition to spatial control, temporal control is easily attainable via addressing laser beam to any channel and dwelling any time. This method realizes flexible high speed, high resolution multi-microchannel electrophoresis that can be applied to a number of high throughput applications.