Project Summary/Abstract The Whitehead Institute requests $600,000 for the purchase of a critically-needed Zeiss LSM 980 with Airyscan 2 laser scanning confocal microscope (“Zeiss 980AS2”), to be located in the W.M. Keck Facility for Biological Imaging (“Keck Facility”) at the Whitehead Institute for Biomedical Research (“Whitehead”). The instrument requested is of great importance, as it will replace a nine year old Zeiss LSM 710 NLO (non-linear optics; “Zeiss710”) that is currently the most heavily used microscope in the Keck Facility and provide transformative new imaging technologies that are currently unavailable at Whitehead or in the Keck Facility. For each of the past 3 years, the Zeiss710 averaged 1400 hours of use by 40 researchers from 25 different labs. Zeiss has informed us that guaranteed service for the Zeiss710 will end in 2022. Replacement of this critical instrumentation prior to that time is important to minimize interruptions caused by excessive maintenance issues. Other microscopy facilities in our area are unable to accommodate the substantial amount of use the Zeiss710 currently supports, and also lack the critical new capabilities required for the proposed research projects. The Zeiss 980AS2 will provide robust confocal capabilities for the diverse research projects described in this proposal, such as enabling optical sectioning to generate high-contrast images in thick specimens, generating 3D datasets, and conducting photomanipulation to analyze molecular dynamics, such as FRAP (fluorescence recovery after photobleaching). Critically, the requested Zeiss 980AS2 will provide new cutting-edge technologies essential for addressing many outstanding questions from the 10 NIH-funded researchers presented in this proposal. The Airyscan 2 detector and software will bring the first super-resolution capabilities to the Keck Facility. The 32-channel spectral detector will allow simultaneous imaging of up to ten fluorophores, enabling studies that investigate cell type differentiation in organoids and tissues. The high-efficiency GaAsP detectors will enable imaging of dim samples and reduce photobleaching and phototoxicity during live-cell imaging. The Airyscan 2 8Y Multiplex option and Z-piezo stage allow for extremely fast image collection, enabling larger sample sizes for large volume scanning. The Zeiss ZEN Blue System software that controls the Zeiss 980AS2 will substantially simplify currently arduous tasks, such as multi-position tile scanning and finding rare events. By expanding the experimental approaches and capabilities available to researchers, the Zeiss 980AS2 will greatly enhance and facilitate the success of many NIH-funded projects, including the analysis of neural degeneration, cancer, germ cell differentiation, metabolic regulation, cell division, and stem cell identification. Acquisition of the Zeiss LSM 980 with Airyscan 2 will allow researchers to address these important biomedical issues, and the outcomes from...