Selectively concentrating cervical carcinoma cells from red blood cells utilizing dielectrophoresis with circular ITO electrodes in stepping electric fields

The detection of rare cells, such as circulating tumor cells, circulating fetal cells, and stem cells, is important for medical diagnostics and characterization. The present study develops a handheld electric module which provides stepping electric fields for dielectrophoresis (DEP) to selectively concentrate cervical carcinoma cells (HeLa) from red blood cells, making it low-cost and automated. To observe the experiments, transparent electrodes were fabricated by patterning indium-tin-oxide-coated glass. Positive dielectrophoretic cells were guided toward the center of the microchamber due to the movement of the high-electric-field region. The magnitude of the DEP force acting on HeLa cells is about seven-fold that acting on red blood cells under a given electric field distribution, making it possible to separate HeLa cells from normal blood cells. HeLa cells were successfully concentrated in 160 seconds with an applied peak-to-peak voltage of 16 V at a frequency of 1 MHz.