There is a growing need for fluorescence-activated cell sorters suitable for purifying primary human cells for preclinical and clinical uses. This poses technical challenges above and beyond those encountered in routine research cell sorting. The primary concerns are reducing the risk of sample contamination while protecting operators from potentially biohazardous aerosols. There are currently no instruments suitable for sorting primary human cells at Washington University or the nearby campus of St. Louis University Health Sciences Center. This proposal requests funds to purchase the inFlux cell sorter (Cytopeia, Inc.). This instrument has several design features that make it well-adapted to sorting human cells. The inFlux will be incorporated into a successful cell sorting core facility directed by the PI within the Alvin J. Siteman Cancer Center at Washington University, an NCI-designated Cancer Center. The proposal by several of the Major Users to use the inFlux for generation of clinical grade cellular products will benefit from a state-of-the-art """"""""Good Manufacturing Practices"""""""" (GMP) facility that is contiguous with the cell sorting core. Construction of the 650 sq. ft. space and support systems for the inFlux have been completed. Ongoing costs for operation and servicing of the inFlux will be provided by the Siteman Cancer Center and offset by user fees. An advisory committee consisting of senior leadership from the Siteman Cancer Center will oversee management and utilization of the inFlux. The Major Users, all established and funded scientists with significant cytometry expertise, will account for 100% of utilization in year one and a minimum of 75% in subsequent years. The remaining hours will be allocated to other investigators at Washington University ant St. Louis University, with priority given to members of the Siteman Cancer Center. This instrument will provide added value for many funded projects at Washington University that collectively accounted for over $328M in total awards from the NIH in 2002, placing it third among medical centers in the United States. ? ? ?