Major advances in technology have made it possible to monitor rapid changes in intracellular ion activities in living cells. the technique involves first loading cells with fluorescent dyes specific for different ions (Ca , H , Cl ). Changes in ion concentration are then measured by monitoring fluorescence from the cells maintained inside the cuvette of a spectrofluorometer. this basic technique involving a population of cells can be extended to analysis of single cells with the appropriate hardware and microscope. Reconstruction of a digitized image by a mini-computer allows 2 and 3-D analysis of cells undergoing changes in ion concentrations. Currently, at Wright State University, there are as many as eight independent investigators using related fluorescent techniques and sharing time on a single instrument. The available instrument has certain drawbacks as well as being heavily used. However, enough significant preliminary data has been obtained to prompt five researchers to request funds under the Instrumentation Program to purchase another spectrofluorometer with dual beam excitation, photodiode array detection, single cell (microscopic) and imaging capabilities. The research proposal of these five investigators involve the measurement of calcium, pH, and chloride in diverse cell types, including astrocytes, vascular smooth muscle, and human diploid fibroblasts. In addition, the requested spectrofluorometer will be used for studies involving membrane fusion such as that which occurs during exocytosis or viral invasion.
