Single-Cell Impedance Spectroscopy of Nucleated Cells

Abstract

Single-cell microfluidic impedance spectroscopy is widely used to characterise single cells, but the intrinsic electrical properties are usually not determined owing to the limited number of data points and frequency bandwidth. To address this shortcoming, we have developed a system with extended frequency range (to 550MHz) to obtain the frequency-dependent spectrum of single nucleated cells at high throughput. The system was evaluated with HL60 cells treated with Glutaraldehyde or Cytochalasin D, and THP-1 cells differentiated into macrophages. The data was fitted to the double-shell model to obtain cell membrane capacitance and cytoplasm conductivity. It is shown that reducing the conductivity of the suspension media enhances the dielectric relaxations of the cell membrane, allowing small differences between control and chemically modified cells to be discriminated.