Using the patch-clamp (PC) and planar lipid bilayer (PLB) techniques the molecular behaviour of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel can be visualised in real-time. The PC technique is a highly powerful and versatile method to investigate CFTR's mechanism of action, interaction with other proteins and physiological role. Using the PLB technique, the structure and function of CFTR can be investigated free from the influence of other proteins. Here we discuss how these techniques are employed to investigate the CFTR Cl- channel with special emphasis on its permeation, conduction and gating properties.