93-61464 Flaming The advent of highly fluorescent cation specific probes coupled with video imaging technologies has led to a sure of interest in photometric measurement of ion distributions in single living cells. Of particular interest has been the quantitation of cytosolic fee calcium concentrations ( Ca2+ i) utilizing the fluorescent dye Fura-2 and dual wavelength ratio imaging. One of the current technical difficulties encountered, but an important goal for Ca2+ i ratio imaging, is the ability to perform real- time imaging (i.e. video frame rates of 30 frames per second). When using Fura-2, the ability to follow fast changes in Ca2+ i can be limited by the rate at which the excitation wavelengths are chopped. If ratioing is to be done in real time, the requirement if that the excitation wavelength be switched within the vertical blanking period of a video signal (1200). The intent of this project is to develop a high speed UV- wavelength switching (excitation) system for real time optical imaging of the nervous system. This Phase I proposal will specifically address the feasibility of utilizing a dual scanning galvanometer system to switch between multiple interference filters. ***
