PROJECT SUMMARY: A user group of seven major, NIH funded, and three minor investigators request $792,426 to purchase a Zeiss Z1 light sheet microscope. This instrumentation and associated equipment will be housed in the Health Science District Advanced Imaging Facility at the University of California Davis. The need for a high-resolution microscope that can rapidly acquire data from large samples is a natural extension of the high-quality images routinely obtained by researchers in this facility. The needs of many researchers for fast imaging of very large volumes or live specimens are not met at any of the core imaging facilities at UC Davis. This request would bring state of the art technology not available at UC Davis, to a designated campus core facility. As such, we believe this microscope greatly expands the capability of our core (and the imaging capability of this campus). This microscope will be integrated into our core facility and its existing infrastructure will integrate the operation, maintenance and management of this instrument. This instrumentation is intended to complement existing infrastructure and accelerate data acquisition. The selective light sheet system from Zeiss is a sensible and cost-effective system that balances resolution, speed, stability, well designed user interface, and ability for customization and upgradability. These attributes make the Z1 system an ideal instrument for our academic facility. As detailed in this proposal the availability of uniquely engineered objective lenses to allow for imaging of samples of several refractive indices is of critical importance. The available objectives and associated accessories allow for imaging of live tissues, organism such as zebrafish, to optically clarified tissues. This setup has been tested by the NIH investigators that comprise the major users, and the minor users of this instrument, and has provided exceptional images and data. Management of this proposed instrument will be integrated into the existing successful imaging facility, which is managed full time Dr. Ingrid Brust-Masher, and guided by a Facility director and advisory board. The HSDAIF serves many researchers from across disciplines of study with advanced instrumentation.