A clogging-free microfluidic platform with an incorporated pneumatically driven membrane-based active valve enabling specific membrane capacitance and cytoplasm conductivity characterization of single cells

This study reports a microfluidic platform for clogging-free electrical property analysis of single cells. A pneumatically driven membrane-based active valve was integrated in this platform to unblock clogging events of constriction microchannels where pneumatic pressures were used to tune the deformation of a polydimethylsiloxan (PDMS) membrane serving as one wall of the constriction microchannel. The proposed platform was first tested to unblock trapped polystyrene beads at the entrance of constriction microchannels and then the characterization of the cellular electrical properties of lung cancer cells was successfully demonstrated. Results showed that the measured cytoplasm conductivity (0.74 +/- 0.20 S/m) and specific membrane capacitance (2.17 +/- 0.58 mu F/cm(2)) of cells were consistent with the results from the previous publications (0.73 +/- 0.17 S/m, and 2.00 +/- 0.60 mu F/cm(2), respectively). Overall, this study has presented a microfluidic platform for single cell analysis with an enhanced function for unblocking cell aggregates at the entrance of microchannels. (C) 2013 Elsevier B.V. All rights reserved.