生物医学的各种实验,特别是分离或检定微生物的一些试验,要求实验动物无菌或无病。普通的实验动物因在开放式的饲养条件下繁殖,不可避免地感染了各种病原体,常由于传染病流行引起大批死亡。为使实验动物达到无菌或无病的标准,国 Biomedical experiments, especially those that separate or test microorganisms, require the animals to be sterile or disease free. Ordinary experimental animals, which breed under open breeding conditions, are inevitably infected with various pathogens and often die in large numbers as a result of the epidemic. To make laboratory animals reach aseptic or disease-free standards, the country