Studying ion channels in undergraduate laboratories

This article describes an undergraduate laboratory that introduces students to ion channels and patch clamp electrophysiology. It is given in conjunction with third year biochemistry lectures on membrane transport proteins and utilises cytoplasmic droplets from Characean algae. These droplets are very easily obtainable (the typical preparation time is around ten minutes), contain abundant channel activity and significantly, readily form the high electrical resistance seals that are required for resolution of single channel events. Most students have been able to observe electrical events that are the result of conformational changes in single protein molecules. When the students are not patch clamping they are set a problem that requires them to devise a model of how several different types of channel might interact to produce a cellular response to osmotic challenge.