We are applying for funds to purchase a Xenogen IVIS(r) Imaging System 100 Series bioluminescence imaging (BLI) workstation to provide our investigators with the ability to conduct in vivo BLI studies. In vivo BLI is a technological advancement that utilizes emitted light from cells or tissues to study real-time gene expression or activity in live animals. BLI requires inserting into cells a luciferase reporter gene under the control of a selected gene promoter. The luciferase-tagged cells are then injected into a mouse or other small animal, or expressed in a transgenic animal, so that their location and activity can be monitored noninvasively via photonic emissions subsequent to the systemic administration of the substrate D-luciferin. In vivo BLI has major applications in the areas of infectious diseases, oncology, and gene expression. The commercial availability and our in-house ability to produce a broad range of tumor cell lines that express luciferase linked to various promoters provides our cancer investigators with the ability to use BLI to study real-time tumor growth, metastasis and therapeutic responses in vivo. BLI also permits real-time assessment of the development and spread of infections, which will lead to a better understanding of host-pathogen interactions and the efficacy of antimicrobial treatments in the context of living animal models. BLI offers several advantages over more traditional assessment methods, including 1) high sensitivity in measuring semi-quantitative differences in cell viability or function within and between groups; 2) a more efficient and accurate assessment of the distribution of expression (that is, tumor expression or patterns of infection, inflammation and stress can be efficiently monitored throughout an entire animal, thus avoiding the possibility of missing unanticipated positive areas); and 3) the ability to assess the same individual subjects at serial time points, thus allowing the use of more sensitive and statistically more powerful repeated-measures paradigms, and removing the need for multiple terminal endpoints. SIU School of Medicine, and its core Research Imaging Facility and Division of Laboratory Animal Medicine will provide the infrastructure and financial support to keep the requested equipment in working order and promote optimal use by participating faculty and staff. The precise and definitive results afforded by in vivo BLI are not possible with the existing technology at our university. Thus, the requested Xenogen BLI system and accessories will greatly benefit our major users and enhance their federally funded research programs through the production of larger volumes of higher quality data. These benefits will also extend to faculty beyond the listed users, thereby increasing their competitiveness for NIH funding. Relevance to Public Health: The IVIS 100 system provides the means by which our investigators will be able to more rapidly and precisely characterize the course of cancer and infectious diseases. Also, the same equipment permits a more efficient way in which effective cancer treatments can be developed and tested. ? ? ?