Ion channels play crucial roles in cell physiology, and are a major class of targets for clinically relevant pharmaceuticals. Because they carry ionic current, the function and pharmacology of ion channels can be studied using electrophysiological approaches that range in resolution from the single molecule to many millions of molecules. This chapter describes electrophysiological approaches for the study of one representative ion channel that is defective in a genetic disease, and that is the target of so-called highly effective modulator therapies now used in the clinic: the cystic fibrosis transmembrane conductance regulator (CFTR). Protocols are provided for studying CFTR expressed heterologously, for CFTR expressed in situ in airway epithelial cells, and for purified or partially purified CFTR protein reconstituted into planar lipid bilayers.
Keywords: CFTR; Electrophysiology; Patch clamp; Planar lipid bilayer; Ussing chamber.