Characterization of stem cell-like property in cancer cells based on single-cell impedance measurement in a microfluidic platform

Investigation of stem cell-like property in cancer cells is important for the development of new therapeutic drugs targeting at malignant tumors. Currently, the standard approach for identifying cancer stem cell-like cells relies on the recognition of stem cell surface markers. However, the reliability remains controversial among biologists. In the current work, a dielectrophoretic and impedimetric hybrid microfluidic platform was developed for capturing single cells and characterizing their stem cell-like property. Single cells were captured in 20 μm trapping wells by dielectrophoretic force and their impedance spectra were measured by an impedance analyzer. The result showed that different cancer cell lines could be differentiated by impedance magnitude ranging between 2 and 20 kHz. Moreover, cancer cells and cancer stem cell-like cells could be categorized by a 2-dimensional graph of the impedance magnitudes at 2 and 20 kHz. The stem cell-like property in cancer cells was verified by stem cell surface markers and single-cell derived colony assay. Comparing with bio-chemical approach, i.e., surface markers, bio-physical approach, i.e., cell impedance, is a label-free technique to identify cancer stem cell-like cells.