This application seeks support under the NCRR Shared Instrumentation Grant Program to update our cytodynamic imaging facility with a state-of the art replacement laser scanning confocal microscope. This research core, established in 1995, and currently utilized by six NIH funded research projects, has had to stop generating data (January, 2002). On June 8th, 2001 tropical storm Allison devastated the basement and ground floor of the Medical school, building services including power and airconditioning were lost for one month. When re-entry was permitted on July 9th, 2001 we found that our existing confocal microscope and computer systems had suffered electrical component damage. The Federal Emergency Management Agency (FEMA) repaired the system hardware ($17,000) but we suffered a second set-back in September 2001 when we discovered that Noran Instruments, the supplier of the existing confocal micrscope, closed business. This left us with no service contract, but more importantly, we lost programming support for the specialized live cell imaging applications our users were running. Specifically, we could not perform either multi-parameter and ratiometric emission imaging. Thus, researchers in this core have had either to find oversubscribed fee-for use services within the Texas Medical Center, or discontinue the live cells imaging aspects of their proposals. A recent survey of new systems has identified the Zeiss 510 META laser scanning confocal microscope as an appropriate replacement for the Noran System because it utilizes an improved acoustical optical deflection technology to fast-scan samples. This has proven to be an essential technical requirement for the live cell imaging experiments outlined in the body of this proposal, whereby it permits: time lapse imaging in three or four dimentions, fluorescence resonence energy transfer (FRET) and multi-track emission fingerprinting. The Department of Integrative Biology has committed extra space and financial support for three additional years of maintenance agreements with Ziess. Thus, institutional support for the requested instrument is present. The Cytodynamic imaging facility has an established organizational structure, which ensures proper sharing of the system. Importantly, not only have we been able to meet the needs of previous core users, but also assisted other NIH funded investigators on a institutional wide basis. ? ?