The extraction of quantitative information from fluorescent probes in living cells using videomicroscopy is emerging as an exciting new approach to the problem of visualizing cell dynamics. Probes which sense cation and anion concentrations, pH and membrane potential allow temporal visualization of these processes, especially dyes which produce images at two different wavelengths. A potentially more exiting application is kinetics of multiple dyes in the same living cell. Present research instruments use rotating filter wheels to change wavelengths and are relatively slow in their data collection rates. Also the high costs for hardware and software prices these custom machines out of the range of most laboratories. Professor Morris and his group are developing a novel design of fluorescence video digital imaging microscope, which captures two video images simultaneously. It is capable of both single excitation/dual emission, for simultaneous observation of two probes in the same live cell. It has no moving parts allowing data collection at any rate for which compatible cameras and storage devices exist. The data collection system uses the AT- bussed PC computer and standard RS-170 video equipment which reduces the cost of the system. Thus it represents state-of-the- art technology at very affordable prices.
