Analysis of individual cells and cell populations at the spatial, temporal and functional level lies at the heart of modern immunology, cell biology and developmental biology. The Cytometry Core focuses on the provision of light microscopal or fluorescence activated cell sorting (FACS) technologies which can be applied in combination with specific molecular probes such as antibodies, DNA, MHC-tetramers, intracellular reporter molecules to address fundamental questions relating to the pathogenesis, treatment and complications of type 1 and 2 diabetes. The Core will be located at the Barbara Davis Center and manned by 2 FTE technical staff under the director ship of Dr. D. Bellgrau. It will use items of large equipment recently obtained from NIH and charitable funding. Twelve services will be offered including standard FACS analyses and immunohistochemistry of solid tissues and more sophisticated analyses of signal transduction and subcellular events in living cells. Formal training will be offered without charge on a biweekly to monthly basis and expert consultation will be available for each of the services provided.