BD FACSAria Fusion cell sorter - Project Summary: We propose the acquisition of a BD FACSAria Fusion cell sorter from BD Biosciences to serve as a crucial instrument for the Ross Flow Cytometry Core (RFCC) in Johns Hopkins University (JHU) School of Medicine (SOM). This 4-laser (Violet 405nm, Blue 488nm, Yellow-Green 561nm, and Red 640nm) model with 16 fluorescent detectors and a fully integrated Class II biosafety cabinet will significantly enhance the research capabilities of the users with NIH funded projects. The current cell sorter, a BD FACSAria IIu with 3 lasers and biosafety cabinet at the RFCC, has limited technical capabilities and declining reliability. It is failing to meet the sorting requirements for advanced research projects. Having served for over two decades, it has reached its End-of-Life stage without manufactory upgrade and coverages. The proposed instrument addresses the pressing and unmet needs of 22 user groups within JHU SOM, spanning diverse research areas with mostly NIH-funded projects or some from other federal funding agencies. These users rely on cell sorter as a critical tool in their research endeavors. The benefits of the Fusion sorter over the current Aria IIu include: 1) the inclusion of a biosafety cabinet enables biosafety level-2 cell sorting with enhanced precautions during sorting operations; 2) the 4 lasers and ample fluorescent detectors reduce spectral overlap, facilitating multi-color panel design; 3) the Yellow-Green laser can optimally excite some unique fluorescent proteins and fluorochromes; 4) improved index sorting into multi-well plates; 5) temperature controls both input and output chambers to improve cell viability and gene stability; 6) easy aseptic setup and cleaning procedures ensure sterile sorting; 7) the well- established cell sorter offers increased reproducibility and expanded capabilities; 8) Conventional sorter easily and simply handle panels with fluorescent protein. The RFCC, under the administration and management of Department of Medicine in SOM, is oversighted by an advisory committee that provides recommendations for successful installation and management of the Fusion cell sorter. For the past 5 years, including COVID pandemic period, the RFCC has provided over 4,750 hours of cell sorting services to about 270 users from JHU SOM and local research community. However, the current BD FACSAria IIu, upgraded from Aria I in 2012 and addition of violet laser in 2015, no longer has a service contract from BD since the end of 2023. With its inability to have further upgrades of lasers, detectors and other parts, as well as timely repair, it is incapable of fulfilling advanced sorting projects. Although expensive high-end cell sorter, especially spectral sorters, are available, the proposed Fusion cell sorter is vital and cost-effective to maintaining a fully functional flow core facility. It should be sufficient to enable innovative researches across a wide range of sorting experiments, from sorting cells expressing fluorescent proteins to deep immunophenotyping, cellular research, genomic research, and other high-performance, high-throughput applications.