Guide for the Care and Use of Laboratory Animals - Office of ...

146 GUIdE FOR ThE CARE ANd USE OF LAbORATORy ANIMALSand rats, especially valuable genetically engineered animals, and SPF animalsof other species.Barrier facilities typically incorporate airlock or special entries (e.g., airor wet showers) for staff and supplies. Staff generally wear dedicated clothingand footwear, or freshly laundered, sterile, or disposable outer garmentssuch as gowns, head and shoe covers, gloves, and sometimes face masksprior to entry. Consumables, such as feed or bedding, that may harborinfectious agents are autoclaved or are gamma-irradiated by the supplierand surface decontaminated on entry. Drinking water may be autoclaved orsubject to specialized treatment (e.g., reverse osmosis filtration) to removeinfectious agents. Caging and other materials with which the animals havedirect contact may be sterilized after washing before reuse. Strict operationalprocedures are frequently established to preclude intermingling ofclean and soiled supplies and personnel groups, depending on work function.Only animals of defined health status are received into the barrier,and once they leave they are prohibited from reentering without retesting.Personnel entry is restricted and those with access are appropriately trainedin procedures that minimize the introduction of contaminants.Engineering features may include high-level filtration of supply air (e.g.,HEPA or 95% efficient filters), pressurization of the barrier with respect tosurrounding areas, and directional airflow from clean to potentially contaminatedareas. Specialized equipment augmenting the barrier may includeisolator cages, individually ventilated cages, and animal changing stations.Detailed information on barrier design, construction, and operationshas been recently published (Hessler 2008; Lipman 2006, 2008).ImagingIn vivo imaging offers noninvasive methods for evaluating structureand function at the level of the whole animal, tissue, or cell, and allowsfor the sequential study of temporal events (Chatham and Blackband 2001;Cherry and Gambhir 2001). Imaging devices vary in the technology usedto generate an image, body targets imaged, resolution, hazard exposure,and requirements for use. The devices may be self-shielded and require nomodifications of the surrounding structure to operate safely, or they mayrequire concrete, solid core masonry, lead-, steel-, or copper-lined walls,or other construction features to operate safely or minimize interferencewith devices and activities in adjacent areas. Because imaging devices areoften expensive to acquire and maintain, and may require specialized supportspace and highly trained personnel to operate, shared animal imagingresources may be preferable.Consideration should be given to the location of the imaging resource.Whether located in the animal facility or in a separate location, cross