Fluorescent labeling for patch-clamp fluorometry (PCF) measurements of real-time protein motion in ion channels

Understanding the function of ion channels is a major goal of molecular neurophysiology. While standard electrophysiological methods are invaluable tools to investigate the gating of ion channels, the structural rearrangements that mediate the way a channel senses physiological signals and opens and closes its gates cannot be measured electrically in a direct way. Here, we describe a method, based on site-specific labeling of a channel of interest with an environmentally sensitive fluorophore, which makes it possible to monitor conformational changes of ion channels in biological membranes in real time.