PROJECT SUMMARY: Cell and Tissue Imaging Core Advanced cellular microscopy is a powerful tool for biological research and plays an important role in the study of the pathogenesis and eventual treatment of diabetes mellitus. Imaging technology has evolved rapidly over the last decade leading to improvements in resolution, sensitivity and speed that have created new opportunities for studying processes across many orders of magnitude and in real-time in living cells and animals. However, the costs of increasingly sophisticated equipment are substantial and the expertise to efficiently use, maintain, and develop this equipment is not common in most labs. There is therefore a significant gap between the availability of these powerful tools and the ability of investigators to access and use them efficiently. The Cell and Tissue Imaging Core was established in response to feedback from DRC center members to leverage the significant institutional investment in the newly created Washington University Center for Cellular Imaging (WUCCI) by providing an integrated approach to investigate the structure and dynamic behavior of diabetes-related cells and tissues. The overall objective of the Core is to provide access to and technical support in using advanced cellular microscopy to accelerate the pace, expand the scope, and improve the efficiency of diabetes research at Washington University. Core services meet the unique requirements of numerous investigators over a wide range of basic and translational research and attract new investigators into diabetes research. Importantly, users benefit from the in-depth diabetes and technical expertise of the Core directors and technical staff in time spent in consultation for experimental design and interpretation of data. During the past funding cycle, the Core served 67 DRC investigator research laboratories (including 14 P&F recipients), who expensed $788,342 in core recharges, representing approximately 18% of all WUCCI activity. Eighteen DRC member laboratories received micro-grant funding through the DRC Imaging Core Scholarship program. Ten of these labs were directed by junior faculty members at the rank of Assistant Professor. Thirty-five publications used and cited core services. Given the broad use of the Core over the past funding cycle, and the establishment of new imaging technologies (e.g. cryo-EM and lattice lightsheet), sample preparation services (e.g. tissue clearing), and analysis approaches (e.g. AI-based immunohistochemistry and immunofluorescent image analysis), it is anticipated that requests for Cell and Tissue Imaging Core services will continue to grow. The substantial demand by DRC members for advanced microscopic imaging and image analysis is strong evidence that the Cell and Tissue Imaging Core provides services that leverage generous institutional support and unique expertise to facilitate important and innovative diabetes research.