SciGro View Institution's Website 1 article published in JoVE Biology Optimized Staining and Proliferation Modeling Methods for Cell Division Monitoring using Cell Tracking Dyes Joseph D. Tario Jr.1, Kristen Humphrey1, Andrew D. Bantly2, Katharine A. Muirhead3, Jonni S. Moore4, Paul K. Wallace1 1Department of Flow and Image Cytometry, Roswell Park Cancer Institute, 2Flow Cytometry & Cell Sorting Resource Laboratory, University of Pennsylvania, 3SciGro, Inc., 4Department of Pathology and Laboratory Medicine, University of Pennsylvania Successful use of cell tracking dyes to monitor immune cell function and proliferation involves several critical steps. We describe methods for: 1) obtaining bright, uniform, reproducible label-ing with membrane dyes; 2) selecting fluorochromes and data acquisition conditions; and 3) choosing a model to quantify cell proliferation based on dye dilution.