(244d) Pulsed-Field Electrophoresis for Microfluidic Devices

Microfluidic device provides many advantages including portable device, low sample consumption, fast separation and short analysis time. In electrophoresis, the motion of particles with different charge and size will lead to separation of different analytes owing to the different electrophoretic mobility under the electric field. One advantage of pulsed field is that it can apply appropriate periodic field to enhance separation. Here, we employed the timing pulsed electric field on microchip, to enhance the separation of free solution electrophoresis. A microchip made of zeonor with a cross channel was used to demonstrate separation of two analytes, which were negative and neutral dyes. The effect of injection, and separation steps were programmed by using a high voltage sequencer. The separation was studied with laser induced fluorescence. CCD camera was used to monitor and record the images for analysis. Fast separation was observed. Furthermore, the pulsed field has higher signal intensity and less dispersion of sample, than the continuous field does. The results indicated that pulsed field could reach the high speed separation with relatively low voltage, reduce dispersion and improve the signal to noise ratio, and resolution, compared with continuous field.