This is a application from a diverse group of six investigators within the Departments of Medicine, Immunology, Pharmacology and Cancer Biology to purchase a BIAcore 3000 biosensor to support 10 ongoing NIH funded research projects in the areas of immunology, blood proteins and signal transduction. Duke University currently has three state-of-the-art biosensors, one BIAcore 2000 and two BIAcore 3000 instruments which are available to the proposed user group on only a limited basis. One older BIAcore 1000 biosensor and one IASys biosensor are available, however, these instruments lack the sensitivity and throughput required for performing the applications of the group of investigators which will require greater than 95 percent of the total usage of the instrument. Access to the instrument will be made available to other users based upon the advice of an internal advisory committee. The instrument will be integrated into the core facilities of the Duke Human Immunology Core Facility and the Duke Specialized Center of Research (SCOR) in Rheumatoid Arthritis. Continued financial support for the operation and maintenance of the instrument will be provided by a charge back mechanism with additional support from the Department of Medicine. A highly skilled investigator has been specifically recruited to Duke University by the Department of Medicine to supervise the day-to-day operations of the instrument. The Department of Medicine will also provide the salary support for a technician who will be the dedicated operator of the instrument. In summary, this group of investigators has a demonstrated need and is requesting support for state-of-the-art BIAcore 3000 biosensor. Advisory committees, institutional support, financial support for continued maintenance and management plans are in place to insure that the instrument will be fully and appropriately utilized.