Project Summary Drexel University is a prestigious, highly diverse R1-level institution built upon a strong history of interdisciplinary collaborations across its many departments and campuses. Drexel University recognizes that state-of-the-art research core facilities are central to the success of individual research operations and the overall research mission of the University. Flow cytometry remains the gold standard for high throughput analysis cells at the single cell level, a critical approach when evaluating heterogeneity in cellular microenvironments. Conventional flow cytometers however are limited by which fluorescent proteins they can detect and the number of concurrent proteins that can be evaluated simultaneously. Spectral flow cytometers are revolutionary in their ability to simultaneously detect and distinguish between fluorescent proteins previously deemed as incompatible with conventional flow cytometers. Drexel University is requesting funds in support of a BD Biosciences Symphony A5 Spectrally Enabled flow cytometer with 5 lasers, 48 fluorescence and 2 scatter channels, and a high-throughput sampler (HTS) system to support deep profiling of cellular heterogeneity in mouse and human samples. This flow cytometer will become the flagship cytometer of the newly created Flow Cytometry Core Facility at Drexel University, to be housed in the Departments of Microbiology and Immunology and Medicine at the College of Medicine and provide support to all flow cytometry users at Drexel University. This application is supported by Major and Minor Users from the Departments of Microbiology and Immunology, Pharmacology and Physiology, and Medicine in the College of Medicine; and the College of Biomedical Engineering, demonstrating the broad impact and need for high parameter flow cytometry.