The Virginia Mason Research Center seeks funding to add a high-speed cell sorter instrument to complement its existing cell analysis capabilities. The VMRC Cell Analysis Facility currently consists of two benchtop analysis instruments and a scanning confocal microscope. The facility currently services a group of 10 principle investigators at VMRC, and provides a range of services including data acquisition and analysis, data archiving, consulting on experimental design, and assistance with data presentation. The existing facility lacks an instrument capable of high-speed cell sorting as well as 5 and 6 color fluorescence analysis. As is described in detail herein, there is a growing need for multi-parameter fluorescence analysis and for high-speed cell-sorting within the user group. This application includes a user group drawn from three institutions that lie in close proximity to one another. They are the Virginia Mason Research Center (where the instrument will be maintained), Puget Sound Blood Center and Pacific Northwest Research Institute. None of the participating institutions currently have high-speed cell sorting capabilities, nor do they have an multi-laser instrument that can perform 5 and 6 color analysis. Several projects cannot currently be performed because they required the ability to sort large numbers of cells for subsequent analysis. Others need to sort relatively rare cells that do not survive extended periods outside of proper culture conditions. Finally, there is a need for an instrument capable of doing DNA content and Ca2+- flux analyses. The instrument requested will provide for the current, as well as future, needs of the user group.