Whole cell electrical impedance spectroscopy for studying ion channel activity

In this work, the micro electrophysiological analysis system (μ-EPAS) is used to study the ion channel activity of single cells. The μ-EPAS has been designed, fabricated, and characterized for this application. The whole cell analysis system has the capability to perform patch clamping, electrical impedance spectroscopy (EIS), and general extracellular recording using integrated, multi-electrode configurations within a single analysis cavity. Bovine chromaffin cells were used as the target cell to demonstrate and characterize the system. Whole cell impedance measurements were taken over a frequency range of 100 Hz to 5.0 MHz. The impedance signatures of bovine chromaffin cells with: i) the K⁺ channels blocked; ii) the Ca²⁺ channels blocked; and iii) unmodified cells were measured and analyzed.