ABSTRACT A quantitative Flow and Tissue Cytometry core (FTCC, core 3) is proposed for the Cooperative Center of Excellence in Hematology (CCEH) to support the research efforts of members of the center. Flow cytometry is an integral research tool for the vast majority of CCEH investigators. Of the 25 current CCEH members, 16 routinely utilize classical flow cytometric services in their research, and more than 65% of their publications over the last 10 years utilized flow cytometric services. However, many need to interpret flow cytometry information in the context of the spatial relationships in the hematopoietic niche; for example, to identify how cells interact with one another and with cellular and physical components of the niche in normal and stressed conditions. To address this need, the FTCC will complement flow cytometry with unique imaging services, including 3D tissue cytometry and intravital microscopy. In this way, the core will offer CCEH members a critical service along with the opportunity to extend their interrogation of hematopoietic cells to include quantitative analyses of the spatial distribution of HSC with other cells during different conditions of nonmalignant hematopoiesis. The FTCC capitalizes on existing shared facilities and expertise present within the Indiana University School of Medicine (IUSM) to provide CCEH members with the latest in technologies and services expected form a sophisticated flow and tissue cytometry facility. The FTCC will provide a cost- effective resource to CCEH investigators who can utilize this core to apply a powerful and integrated approach to studies of non-malignant hematology that will be an invaluable asset to their research, as well as to hematology investigators across the country. The specific aims of the FTCC are: 1- Provide outstanding, consistent, timely, and economical multicolor analysis, cell sorting, image flow analysis, and single cell proteomic analysis to all CCEH members to facilitate the conduct of their research in hematopoiesis and stem cell biology that requires any of these services. 2- Enhance the productivity of CCEH members by providing centralized and standardized flow cytometric and other related services that allow for the exchange of protocols and results between investigators within and outside Indiana University and advance the distribution of scientific knowledge. 3-Provide CCEH members with large-scale 3D and highly-multiplexed 2D tissue cytometry services, extending from study design, fluorescence labeling, image collection, quantitative image analysis and supervised and unsupervised data analysis. 4- Provide CCEH members with intravital microscopy services, including preparation of institutional compliance documents, study design, animal surgery, image collection and quantitative image analysis. This arrangement will give CCEH investigators and all investigators Nationwide, powerful new tools for their nonmalignant hematology investigations.