A Hybrid Electrokinetic-Microfluidic Chip for Isolating CTCs in Physiological Sample

This paper reports a hybrid electrokinetic-microfluidic chip, which combines electrophoresis (EP), dielectrophoresis (DEP) or AC electrothermal flow (ACEF), for isolating circulating tumor cells (CTCs) in physiological sample. While most electrokinetic techniques only function in low-conductivity buffers, hybrid electrokinetics enables effective operation in high-conductivity samples (1 S/m), which are compatible to physiological fluids such as blood, buffy coat and urine. Using a 3-electrode configuration and optimizing AC voltage, frequency and DC offset, we demonstrate that breast cancer cell can be localized within 10 sec in buffy coat without any pretreatment.