A hybrid dielectrophoretic and hydrophoretic microchip for particle sorting using integrated prefocusing and sorting steps.

This work explores dielectrophoresis (DEP)-active hydrophoresis in sorting particles and cells. The device consists of prefocusing region and sorting region with great potential to be integrated into advanced lab-on-a-chip bioanalysis devices. Particles or cells can be focused in the prefocusing region and then sorted in the sorting region. The DEP-active hydrophoretic sorting is not only based on size but also on dielectric properties of the particles or cells of interest without any labelling. A mixture of 3 and 10 μm particles were sorted and collected from corresponding outlets with high separation efficiency. According to the different dielectric properties of viable and nonviable Chinese Hamster Ovary (CHO) cells at the medium conductivity of 0.03 S/m, the viable CHO cells were focused well and sorted from cell sample with a high purity.