Assessment of dielectrophoresis for sorting trophoblast from blood

Non-invasive methods for isolating fetal cells from the maternal circulatio n have been used for prenatal genetic diagnostic purposes. Unfortunately, m ost of the currently available separation methods are antibody based, and l imited by the lack of specific fetal markers. Our aim is to develop a novel technique for the isolation of trophoblast from the maternal circulation. We employed dielectrophoresis (DEP) which uses non-uniform alternating curr ent (AC) electric fields to isolate subpopulations of cells from a heteroge neous cell group. DEP separates on the basis of differences in the dielectr ic properties of different cell types e.g. membrane capacitance and membran e conductivity. We have demonstrated the ability of the system to separate trophoblast from binary mixtures of peripheral blood mononuclear cells (PBM Cs) and placentally derived trophoblast cells. We have shown enrichment of trophoblast cells of up to thirty times with almost complete depletion of c ontaminating PBMCs.