Dielectrophoretic discrimination of cancer cells on a microchip

The analysis of single cell type typically requires expensive equipments in combination with labeling techniques. As a label-free alternative, in this letter, the characteristic dielectric properties of various cancer cell lines (MCF-7, SKOV-3, MDA-MB-231, and LnCap) and healthy peripheral blood mononuclear cells were examined and compared using the dielectrophoretic (DEP) crossover frequency technique. We found that each type of the cancer cells shows a distinct DEP crossover frequency with an order of SKOV-3, MDA-MB-231, MCF-7, and LnCap from low to high frequency, from which the specific cell membrane capacitance and membrane conductance could be derived. Cell fixation and antibody coupling were found to have minimal or no effects on the cell dielectric properties while cell permeabilization significantly changed the DEP crossover frequency. These findings suggested that the DEP crossover frequency is promising to be used as a "dielectric finger print" to discriminate different cell types and may even enable the specific manipulation of certain cell types, for example, to isolate cancer cells from blood. (C) 2014 AIP Publishing LLC.