Flow Cytometry Shared Resource Summary The mission of the Masonic Cancer Center (MCC) Flow Cytometry Shared Resource (FCSR) is to provide cost-effective and comprehensive state-of-the-art services and training in all aspects of flow cytometry to MCC personnel. Flow cytometry is essential for almost all cancer biology laboratories because it permits multiparametric cell analyses and the physical isolation of phenotypically defined cell subsets for subsequent analysis or manipulation. Accordingly, the FCSR supports 3 pillars in MCC’s strategic plan: 1) drive research discovery; 2) accelerate the path to cures; and 3) enable research excellence. MCC researchers currently have 24/7 access to 8 self-service flow cytometers and weekday access to 4 staff- operated cell sorters. FCSR staff support the use of each instrument and bring decades of experience and expertise in flow cytometry to MCC. This provides stability in the daily operations and ensures that MCC users’ flow cytometry needs are met. The Resource’s reputation for excellence and innovation in the national flow cytometry community allows us to beta-test new reagents and equipment provided by industry. This affords us a competitive advantage because MCC researchers gain working knowledge of new technologies before they become widely available. The costs of using the instruments are billed on an hourly basis, with the rates subsidized for MCC users. FCSR has been led by Dr. Christopher Pennell (Immunology Program) since 2012. In January 2022, Dr. Pennell was named as leader of the broader University Flow Cytometry Resource, of which FCSR is a part. In his expanded role, he remains the Director of the FCSR and is supported by 5 staff members. To continue supporting MCC research with outstanding flow cytometry equipment and services, we propose the following specific aims: Aim 1: To provide MCC researchers with 24/7 access to advanced flow cytometric instruments. Aim 2: To aid MCC researchers in the design of flow cytometry experiments, data acquisition, and data interpretation. Aim 3: To educate MCC researchers regarding the principles of flow cytometry, to train users on self-service analyzers and cell sorters, and to share cutting-edge advancements in flow cytometry. Aim 4: To beta-test new reagents and equipment and to continually upgrade equipment. FCSR was used by 162 people during fiscal year 2022, of whom 103 were members of MCC.