Ion Transport is a collection of papers from the Smith Kline & French Research "Symposium on Ion Transport" held in Cambridge, on April 12-14, 1989. These papers focus on the plasma membrane, particularly on the three main classes of transporters, namely, pumps, exchangers, and channels. Some papers discuss the different experimental approaches from electrophysiological and ion flux measurements through pharmacology, molecular biology, electrostatics, and computer modeling. Other papers discuss the P-type cation pump, a class of ATP-driven ion pumps, which is determined from its subunit composition and from the results of the hydrolysis of ATP. Several papers explain the techniques used in ion channels and their modulation. These techniques can be used in the voltage-gated Na+ channel or in permeation mechanisms. Other papers examine the transport proteins involved in the physiology of ion transport. Ions and fluid transport relate to, at the molecular level, how ions cross membranes. A minimum model, in conjunction with theoretical perspective, can describe the mechanism by which ions move through channels. This collection can prove beneficial for biochemists, micro-biologists, cellular researchers, and academicians involved in the study of cellular biology or biophysics.