Studying different effects on the collection efficiency of a dielectrophoresis based selective filter in a microchip with integrated flow cytometers

Dielectrophoresis (DEP) and flow cytometry are powerful technologies and widely applied in microfluidic systems for handling and measuring cells and particles. Here we present a novel microchip with a positive DEP selective filter integrated with two micro flow cytometers for real-time monitoring of cell sorting processes. On the microchip, two flow cytometers are set upstream and downstream of the DEP filter. When a cell pass through the detection windows, the light scattered by the cell is measured by integrated polymer optical elements. The effects of flow rate, applied voltage, conductivity of the sample, and frequency of the electric field on the sorting efficiency of the chip were investigated. Using the chip, viable and non-viable yeast cells were sorted with high efficiency. At 2 MHz, more than 90 % of the viable and less than 10 % of the non-vial cells were captured on the DEP filter. Furthermore, the microstructure is simple to fabricate and can easily be integrated with other microstructures for lab-on-a-chip applications (164).