Laser light-scattering system for studying cell volume regulation and membrane transport processes

A simple and relatively inexpensive device utilizing laser light scattering for the study of volume regulatory behavior and membrane transport phenomena in cells cultured on or affixed to a rigid substrate is described in detail. Validation of the method is provided by study of cell types with known volume regulatory responses. The method we describe has numerous advantages over currently available techniques used to monitor cell volume changes. These advantages include 1) the ability to rapidly detect and quantify small cell volume changes on-line, 2) the ability to maintain natural cell morphology, cell surface contacts, and cell-to-cell interactions, 3) the ability to easily control solution temperature and gas and solute composition, and 4) the ability to perform multiple perturbations in a single experiment. The light-scattering system we describe can be modified to allow for simultaneous measurement of light-scattering signals and fluorescence emission from intracellular ion-sensitive probes and membrane potential dyes. In addition, our method may be useful for the study of apical and basolateral membrane transport processes in epithelial monolayer cell cultures.