High-Speed Single-Cell Dielectric Spectroscopy.

Single-cell impedance cytometry is a label-free analysis technique that is now widely used to measure the electrical properties of a cell and to differentiate different subpopulations. Current techniques are limited to measuring the impedance of a single cell at one or two simultaneous frequencies. Also, there are no methods that extrapolate the intrinsic electrical properties of single cells. We demonstrate a new approach that uses multifrequency impedance measurements to determine the complete intrinsic electrical properties of thousands of single cells at high throughput. The applicability of the method is demonstrated by measuring the properties of red blood cells and red cell ghosts, deriving the unique values of conductivity and permittivity of the membrane and cytoplasm for each individual cell.