The UAB Flow Cytometry and High-Speed Cell Sorting Facility provides expert assistance and instruments for analysis of particles and cells that is available to all NIH-funded researchers at UAB. The current equipment in the core includes a FACS Vantage (since upgraded to DiVa), a FACS Calibur and a FACScan, which were purchased with support from both the NIH and the institution. These cytometers have limited capabilities in the number and type of fluorochromes and fluorescent particles they can detect. In this proposal, twenty-three NIH-funded, UAB investigators request funds for purchase of a BD LSR II cytometer. The LSR II will be equipped with a solid-state 488nm blue laser (20mw) a JDS Uniphase 633nm Red laser (18mw) and 405nm Violet laser (25mw) and a 532nm Green laser (Variable 0-150 mw). The system will have the ability to detect 2 colors from the blue laser plus side and forward scatter utilizing a trigon optical array, 3 colors from the red laser utilizing a trigon optical array, 8 colors off the violet laser utilizing an octagon optical array and 5 colors off the green laser utilizing an octagon optical array. The system is capable of collecting up to 20 parameters. The collected emission light will be delivered to the optical arrays by fiber optic technology. Appropriate bandpass filters and dichroic mirrors are included. The LSR II cytometer will provide access to three technologies not currently available to UAB researchers: Multi-parameter analysis of a wide spectrum of fluorochromes; Excitation and detection of emission for multiple reporter constructs; Excitation and detection of fluorescent emission from quantum dots. This proposal documents the experimental plans of the co-investigators for use of the expanded technical capabilities, the absence of accessible alternatives, and the institutional administrative and material support for this cytometer. Combined with efforts by the Facility in investigator education and outreach, this proposal will significantly improve the flow cytometry services in support of NIH funded projects at UAB. [unreadable] [unreadable]