A simple transport system for radiation treatment of specific pathogen-free mice in lifetime studies

To prevent the introduction of pathogens, specific pathogen-free (SPF) faci lities generally have a "once out, never back" policy with respect to anima ls and materials. In a lifetime study of the long-term effects of ionizing radiation exposure in mice, large numbers of SPF mice needed to be transpor ted from clean-animal barrier labs to a multiuser conventional building for radiation treatment and then back into the animal facility. The convention al building is known to harbor wild mice as web as insects, spiders, and mi tes, and this situation might potentiate the transfer of wild mouse pathoge ns to laboratory animals. Introduction of pathogens into the mouse populati on would jeopardize the entire study, but the radiation treatments were an essential component of the study. These considerations prompted development of a system for transporting individual animals out of and back into the f acility without exposure to pathogens. The system consists of reusable tran sport/treatment vessels and transport protocols designed to minimize the po tential for pathogen exposure.