Ward Gina M, Cole Kelly, Faerber Jennifer, Hankenson F Claire
University Laboratory Animal Resources, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
J Am Assoc Lab Anim Sci. 2009 Nov;48(6):774-9.
Contemporary rodent caging and equipment often are sterilized by steam autoclaves prior to use in facilities. This work assessed the microenvironment of unoccupied static mouse cages after steam sterilization to determine when internal temperatures had cooled to levels appropriate for rodent housing. Polycarbonate static cages containing food and corncob bedding were stacked (10 rows x 7 columns) in duplicate (front and back; n = 140 cages) on a storage truck and autoclaved to 249 degrees F (121 degrees C). Cages (n = 6) were assessed to represent top, middle, and bottom rows and edges of columns. After cage sterilization, hygrothermometers were placed in cages to measure internal cage temperature (IT), bedding temperature (BT), and cage humidity (CH) every 10 min for 150 min. At time 0, there were no significant differences in averaged temperatures or humidity across cage locations: IT, 95.9 degrees F; BT, 109.8 degrees F; and CH, 84.1%. Over time, significant positional effects occurred. Whereas IT and BT for cages in the center row cooled more slowly than those on the bottom row, CH in top row cages decreased more quickly compared with other cages. After 150 min, the average measures overall were IT, 75.8 degrees F; BT, 77.9 degrees F; and CH, 82.4%. Comparison of the overall measures at 150 min with those of cages cooled overnight (IT, 72.4 degrees F; BT, 71.0 degrees F; and CH, 49%) and cages housing mice (IT, 72.2 degrees F; BT, 70.7 degrees F; and CH, 82%) indicated that a poststerilization cooling period of greater than 2.5 h was necessary to achieve permissible rodent housing conditions at our institution, particularly with corncob bedding autoclaved within the cage.
当代啮齿动物饲养笼具和设备在设施中使用前通常通过蒸汽高压灭菌器进行消毒。这项工作评估了蒸汽灭菌后空置静态小鼠笼的微环境，以确定内部温度何时冷却到适合啮齿动物饲养的水平。装有食物和玉米芯垫料的聚碳酸酯静态笼（10行×7列）一式两份（前后；n = 140个笼子）堆叠在一辆运输卡车上，并高压灭菌至249华氏度（121摄氏度）。评估笼子（n = 6）以代表顶部、中间和底部行以及列的边缘。笼子灭菌后，将温湿度计放入笼子中，每10分钟测量一次笼子内部温度（IT）、垫料温度（BT）和笼子湿度（CH），持续150分钟。在时间0时，不同笼子位置的平均温度或湿度没有显著差异：IT为95.9华氏度；BT为109.8华氏度；CH为84.1%。随着时间的推移，出现了显著的位置效应。中间行笼子的IT和BT冷却速度比底部行的笼子慢，而顶部行笼子的CH与其他笼子相比下降得更快。150分钟后，总体平均测量值为IT 75.8华氏度；BT 77.9华氏度；CH 82.4%。将150分钟时的总体测量值与过夜冷却的笼子（IT 72.4华氏度；BT 71.0华氏度；CH 49%）和饲养小鼠的笼子（IT 72.2华氏度；BT 70.7华氏度；CH 82%）进行比较表明，在我们机构，灭菌后需要超过2.5小时的冷却期才能达到允许的啮齿动物饲养条件，特别是对于笼内高压灭菌的玉米芯垫料。
