PROJECT SUMMARY The Gnotobiotic Animal Core (GNAC) is a specialized mouse care facility that is shared by investigators within and outside of the University of Washington (UW). It is located in the specific pathogen free (SPF) vivarium in the Health Sciences Buildings at UW and occupies ~1750 sq ft consisting of four separate rooms. It is managed by two faculty members and highly trained GNAC Staff in the Department of Comparative Medicine. The GNAC is a complete research support facility: We create and care for gnotobiotic and germ-free mice housed in the core and provide technical support for diverse gnotobiotic research needs. A particular strength of the core is that new investigators can conduct small pilot projects by using the ready-to-go expertise of GNAC staff even if they do not have the extensive training needed for such studies. The GNAC has been operational for over seven years, and during this period, more than forty investigators from fifteen different research groups have used the GNAC. Over twenty publications have been generated with support from twenty-three federal grants and twelve private foundation/institutional grants. GNAC utilizes two housing systems: Flexible-film isolators are used for breeding and maintenance of various strains of GF mice, and isopositive cages are used for mice during experiments. The isopositive cages are highly specialized, air-tight, HEPA filtered, bioexclusion cages (ISOcage P caging manufactured by Tecniplast). When paired with using a biosafety cabinet and sterile technique, the isopositive cages offer a more user-friendly alternative to isolators for investigators to maintain and manipulate gnotobiotic mice. The goal of this application is to retrofit existing ISOcage P cages with a Digital Ventilated Cage Rack Environment Monitoring (DVC REM) system. The DVC REM system will monitor cage- and rack- level environments as well as global animal activity within each cage continuously. This modernization will greatly enhance several experimental and husbandry-related aspects of gnotobiotic research using mice: 1) improved experimental rigor, reproducibility and translation of experiments, resulting in reduced number of research animals needed to address complex research questions; 2) improved animal welfare by providing 24/7 monitoring that will alert investigators to problems with animal health or the caging environment; and 3) improved time management for GNAC staff during animal husbandry practices by streamlining scheduling of animal care- related tasks and preparing and rotating supplies. Successful completion of our proposed plan will broadly benefit all investigators using the facility by helping to maximize the use of limited resources and to improve reproducibility in animal research by providing unprecedented continuous monitoring of environment and animal activities.