(535a) Entrapment of Human Leukemia Cells From Blood Using Contactless Dielectrophoresis

Dielectrophoresis (DEP), the motion of particles in a non-uniform electric field, has become a robust technique for analyzing cells, micro particles based on their physical and electrical signatures. A new method, contactless Dielectrophoresis (cDEP), shows a good potential to subdue the common trade-offs between sample throughput and selectivity without the need for complicated fabrication processes as evident from conventional sample enrichment techniques. cDEP has been recently used for successful isolation of THP-1 human leukemia monocytes from a heterogeneous mixture of live and dead cells in our laboratories. The absence of contact between electrodes and the sample fluid channel prevent bubble nucleation and avoids any cross contaminating effects the electrodes might have on the sample. In cDEP electrodes are capacitively coupled to the sample containing fluidic channel through dielectric barriers; the application of a high-frequency electric field to these electrodes then induces an electric field in the channel. In order for us to selectively isolate THP-1 tumor initiating cells from blood samples using cDEP with minimal erythrocyte trapping, the Clausius-Mosotti factor of cells was changed using the cell suspension media conductivity as an tuning parameter in the ranges of 100uS/cm2 -300uS/cm2 which in turn is speculated to increase crossover frequency thus aiding in efficient entrapment of the tumor cells from blood. Our preliminary results indicate contactless Dielectrophoresis as an efficient way to detect, isolate and further enrich Circulating Tumor Cells (CTC's) within the biological fluids.