This core will offer high-speed flow cytometry to acquire and sort samples at 70,000 events per second, permitting rare event detection such as of antigen-specific T cells. CFC assays on memory subpopulations will be conducted on this instrument. The configuration will be set initially for nine fluorescent colors and 4-way cell sorting with opion to evolve to twelve colors. Single cell sorting into 96 well plates will allow for efficient TCR repertoire analysis. Tetramer staining and other biomarker measurements in blood and skin will be performed in this core. No instrument with equivalent speed, multiparameter simultaneous analysis and biocontainment options is currently available in the Harvard Medical School area and affiliates.