This proposal seeks funding to support major alteration and renovation of the cage wash area in the Braun Mouse Facility (BMF) at the California Institute of Technology (Caltech) including purchase and installation of several major fixed equipment items. Major pieces of fixed equipment to be purchased include: a tunnel washer, a HEPA filtered bedding waste station, a bedding dispensing unit, and a water softener. The proposed major upgrades to the cage wash area requiring A&R include: installation of newly purchased fixed equipment; creation of an airlock/gowning area at the cage wash facility entrance; relocation of existing fixed equipment items to adjacent mechnical space to optimize usable work space and improve work flow; and extensive ceiling work including installation of: exhaust air canopies above 2 autoclaves, and flush mounted moisture-proof light fixtures and concealed fire sprinkler heads. In addition, existing air supply HEPA filters which are surface mnounted will be reinstalled so they are flushed mounted. The BMF, a full barrier facility, is used by 88% of Caltech investigators using animals in research, to house genetically engineered mice created at Caltech. The proposed upgrades are necessary to support the continued conduct of PHS supported biomedical research at Caltech. Emphasis is placed on ensuring compliance with the NRC Guide and maintaining AAALAC accreditation through maintaining or improving animal health and welfare, correcting potential human life safety hazards, and improving labor and space utilization efficiency. ? ? ?