A DIELECTROPHORESIS-BASED BIO-SAMPLE PREPARATION

Dielectrophoresis (DEP) force is generated by dielectrically polarized particles in non-uniform electrical fields. In this paper, we report the use of DEP in microfluidic sample preparation. The chip uses DEP force to concentrate mammal cells and magnetic beads, in order to extract and purify mRNA from these cells. Both the mammal cells and magnetic beads exhibit negative DEP properties and are concentrated in the same region in the electrical field ie. regions of weaker electrical field of the chip. Therefore, the magnetic beads coated with Oligo (dT) can easily capture mRNA released from the cells when cell is lysed by chemical lyse. Thus a high mRNA yield can be obtained. Silicon is used to make the chip channel and the DEP electrodes. The working principle of the micro-fluidic chip, its fabrication process and experiment results are described in this report.