Investigators from the University of Iowa College of Medicine request support to purchase a high-performance Flow Cytometry Instrument. The need is to have available a Flow Cytometry Instrument capable of high speed sorting and multi- parameter analysis. The major users of this instrumentation have research programs that are federally funded and that require sorting of stem cells, dendritic cells and mutant clones. The instrument would reside in, and be managed by, the College of Medicine Flow Cytometry Facility located in room 48 of the Eckstein Medical Research Building at the University of Iowa. The Flow Cytometry Facility is a Core Facility. The acquisition of this instrument would allow investigators to pursue research directions not now feasible. It will expand the techniques and methods that can be brought to bear on the stem cell, dendritic cells and various immunological research projects being pursued by a large number of researchers at the University of Iowa.