LASER LIGHT-SCATTERING SYSTEM FOR STUDYING CELL-VOLUME REGULATION ANDMEMBRANE-TRANSPORT PROCESSES

A simple and relatively inexpensive device utilizing laser light scatt ering for the study of volume regulatory behavior and membrane transpo rt phenomena in cells cultured on or affixed to a rigid substrate is d escribed in detail. Validation of the method is provided by study of c ell types with known volume regulatory responses. The method we descri be 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) t he ability to maintain. natural cell morphology, cell surface contacts , and cell-to-cell interactions, 3) the ability to easily control solu tion temperature and gas and solute composition, and 4) the ability to perform multiple perturbations in a single experiment. The light-scat tering system we describe can be modified to allow for simultaneous me asurement of light-scattering signals and fluorescence emission from i ntracellular ion-sensitive probes and membrane potential dyes. In addi tion, our method may be useful for the study of apical and basolateral membrane transport processes in epithelial monolayer cell cultures.