This book contains transcripts of the lectures given at the international symposium on Organellar Ion Channels and Transporters, which was held in September, 1995, at the Marine Biological Laboratory in Woods Hole, Massachusetts, under the auspices of the Society of General Physiologists. The symposium focused on the biochemistry, molecular biology, structure/function, and physiology of ion channels and transporters found in intracellular membranes such as the endoplasmic reticulum, mitochondria, and nucleus. The overall aim of the symposium was to integrate the physiologic, biochemical, and genetic approaches to the study of this class of membrane proteins and to provide a focus for discussion of this exciting new frontier of membrane biology.