Isolation of Rare Cells through their Dielectrophoretic Signature

There are various situations in which it is desirable to separate bioparticles, such as DNA, viruses, bacterial or mammalian cells from background [1]. Here, we focus on the isolation of rare mammalian cells, from cell mixtures or body fluids for cancer detection and individualized medicine using electrophoresis (DEP) [2]. Isolating rare cells is challenging, mostly due to their low number compared to background cells. For example, in screening for circulating tumor cells (CTCs) to detect cancer, there are only a few CTCs per mL of blood, which includes approximately a billion red blood cells and a million white blood cells. Specifically, it has been reported that there are less than 5 CTCs per 7.5 ml blood, detectable using immunomagnetic labeling in patients diagnosed with metastatic breast cancer [3]. Moreover, in some applications, rare cells are similar in size with background cells, which make rare cell isolation difficult.