Trap probability analysis of DNA trap using electric and hydrodrag force fields in taper shaped microchannel

Extraction of a specific molecule from cells is one of the important issues for the muTAS. However, current microfluidic device technologies are not sufficient for extraction and purification of DNA, RNA and proteins from cells. We reported earlier a selective DNA trapping employing mutually reverse electric force and hydrodrag force field in a micro-fabricated taper-shaped channel. This technique can trap biomolecules such as DNA selectively by tuning the ratio of the two forces employing relatively large structure compared to the case of DNA trap by dielectrophoresis. In this paper, we try to study the mechanism of the DNA trap by measurement of trap probability in taper shape micro structure, which was made using EB lithography and dry etching on quartz chip in order to improve fabrication accuracy and reproducibility. The results were compared to numerical simulation done by COMSOL software.