In-Flow Dielectrophoresis Sensor for Measuring the Dielectric Spectrum of Single Cells: Viable and Non-viable Cells

The dielectric properties of biological cells can be used to gain information on their physiology and morphology. We present a wideband dielectrophoresis (DEP) sensor that measures the dielectric spectrum of single cells while they flow through a microfluidic channel. We describe how an asymmetric co-planar electrode array can be used to apply DEP actuation to individual cells and then accurately measure their translation. This enables determination of the equivalent complex dielectric permittivity of the cell. Measurement over the beta-dispersion (interfacial) frequency range then facilitates determination of the cell's structural dimensions and the dielectric properties of its compartments. We measure the dielectric spectrums of viable and non-viable Chinese hamster ovary (CHO) cells, as induced through starvation, and show how they are related to changes in the cell's membrane permittivity and cytoplasm conductivity.