Project Summary This shared instrument grant requests funds for a new flow cytometer, the Sony MA900, to be installed at Yale University and dedicated to BSL3 research using fluorescence-based flow cytometry for either cell sorting or purely analytic purposes. Flow Cytometry is a critical resource for biomedical research. Nearly every discipline in the biologic sciences uses this technology that can be critical for a variety of applications downstream of the sorting of cells based on phenotype. There is strong interest in studying infectious disease at Yale – both at the cellular and host-response level. Many investigators performing BSL3 research rely on a cell-sorting flow cytometer within the BSL3 facility to process infected cell samples that can not undergo fixation. This is particularly important when cell sorting of unfixed infected samples is required for subsequent in vitro cell culture assays or single cell RNA sequencing. Numerous high-impact papers have resulted from prior BSL3 research at our institution, but many on-going studies require continued access to reliable BSL3 flow cytometry. The requested equipment would replace an aging BD FACSAria. The vendor will soon cease to offer service contracts on this model. Since this is the only cell-sorting flow cytometer available for BSL3 researchers, any equipment breakdown could result in delays that would significantly impede ongoing research. Thus, it is critical that this instrument be replaced with a reliable cell-sorter that can be repaired in a timely fashion, preferably one that can be operated independently by investigators when staff is not available.