The University of Florida has embarked upon building a series of major research initiatives. These include the Shands Cancer Center, McKnight Brain Institute, UF Genetics Institute, and the Center for Immunology. These initiatives have brought in and are continuing to hire many new faculties. As a result of two (2) of these initiatives, the Cancer Center and Genetics Institute, the University is in the process of building a new 280,000 research building in which to house these two research programs. This new Cancer & Genetics research building will also house an SPF rodent animal facility with a 17,000-cage capacity. One (1) major piece of shared equipment lacking in this new SPF animal facility is an irradiator. As you will see in this application an irradiator is a vital piece of shared equipment that will greatly benefit our growing NIH supported research initiatives. We are requesting funds to purchase an MDS Nordion Inc. Gammacell 40 Exactor Self-Contained Low Dose Rate Research Irradiator (Cat. # GC40) complete with two cesium 137 sources (Cat. # GC40C440), which will be capable of delivering a central dose rate of 110 rad/min. In this proposal we are also requesting funds for the purchase of a set of 3 attenuators, a sample cavity collimator and a sample drawer tray.