Continuous separation of cancer cells from blood in a microfluidic channel using dielectrophoresis

Currently, there is enormous interest in developing microfluidic lab-on-a chip devices for biological and clinical purposes. In this work, a method for continuous separation of cancer cells from diluted blood in a microfluidic device using dielectrophoresis is described. MDA-MB-231 breast cancer cells have been separated from normal blood cells with high level of accuracy that could enabled precise counting of the cancer cells in samples. The cancer cells were separated from the mixture of cells to a different daughter channel using two pairs of interdigitated comb-like electrode deposited in the microchannel. All experiments were performed with sucrose/dextrose conductivity adjusted medium. The AC signals used in the separation of cancer cells from the mixture are 20 V peak-to-peak with frequencies in range of 10 - 60 kHz. The separation is a result of balancing of magnitude of the dielectrophoretic force and hydrodynamic force on cells. The difference in response in response between cancer malignant cells and normal cells at a certain band of alternating current frequencies was used for rapid separation of cancer cells from blood. The significance of these experimental results are discussed, with detailed reporting on the preparation of cells and medium, flow condition and the fabrication process of the microfluidic separation microdevice. The present technique could potentially be applied to identify incident cancer at a stage and size that is not yet detectable by standard diagnostic techniques for detecting of cancer recurrences.