(419c) Separation of Particles Using Contactless Dielectrophoresis and Electrokinetic Flow

Dielectrophoresis (DEP), the motion of a particle in a non-uniform electric field, has become a robust method for analyzing nano-particles, cells, viruses, and DNA based on their physical and electrical properties. A new technique, contactless Dielectrophoresis (cDEP), isolates cells from contact with the electrodes. This is achieved by using fluid electrodes which are isolated from the sample channel by thin insulating membranes. The absence of contact between electrodes and the sample fluid inside the channel prevents bubble formation and avoids any contaminating effects the electrodes may have on the sample. This technique has demonstrated the ability to isolate THP-1 human leukemia monocytes from a heterogeneous mixture of live and dead cells as well as discriminate between cells of different metastatic potential. Recently, this technique has been improved for operation at frequencies as low as 1 kHz, allowing us to manipulate cells using both positive and negative DEP. Typically, this technique relies on the use of pressure driven flow which creates a non-uniform flow velocity and requires the use of a syringe pump.  This work presents the analysis and evaluation of the combination of cDEP with electrokinetic flow to isolate and enrich particles.