In recent years, the Indiana University School of Medicine (IUSM) has sustained a substantial increase in the use of genetically engineered mice (GEM). These animals are critical for the School's designated areas of major research growth, including cancer, diabetes, and HIV/AIDS. As a result of this growth in the use of GEM and the recent completion of new laboratory space for many of the scientists who conduct research involving these animals, we need to create more efficient and larger housing capacity for their use in IUSM's Laboratory Animal Resource Center (LARC). In 2007, institutional resources permitted the installation of a reverse osmosis water purification system in the Medical Research and Laboratory Building (MRLB), one of IUSM's major LARC facilities. Although this single unit was designed at a capacity to serve the entire MRLB rodent housing area, the automatic watering system plumbing could only be installed in one suite of the facility. Funds from the current grant proposal will be used to purchase the equipment necessary to deliver purified water to individually ventilated cages throughout the remainder of the rodent housing space in the MRLB via the automatic watering system. This will enable IUSM to improve efficient use of personnel and to reduce the operational costs associated with LARC facilities while maintaining the highest level of animal care possible. It also will allow IUSM to protect LARC animal staff by reducing the potential for ergonomic injuries associated with the use of water bottles.