Dielectrophoretic chromatography with cross-flow injection

Abstract

This paper reports the separation of particles using Dielectrophoretic (DEP) chromatography device. The device consists of a cross-flow injector, similar to that used in a capillary electrophoresis chip, and an array of interdigitated microelectrodes for separation, to which radio-frequency voltage (/spl sim/5V, 1MHz) is applied. All liquid actuation is done by hydrostatic pressure. The sample is fed pulse-wise to the carrier flow using the cross-flow injector. The particles in the sample undergo the non-uniform field created by the electrode array, and more polarizable the particle is, the higher the chance of the trapping by DEP force becomes, and as a result, more delayed from the carrier flow. Thus, a separation depending on the size and the dielectric properties of the particle become possible. Using the device, the separation of 1) 0.1 /spl mu/m and 1.0 /spl mu/m latex particles, 2) 6.6kbp and 48.5kbp DNA, are experimentally demonstrated.