Aseptic transport of axenic mice between laboratories requires a specially designed sterile shipping container. The shipping container is essentially a small isolator without forced ventilation. It usually consists of a flexible polypropylene container with disposable cages inside; two HEPA filters, one on top and the other on one end; and a disk seal through which materials or animals are moved between the container and the isolator. During shipping, the container is protected in a transport box. We supply food and water during shipping either with moistened chow or with commercial, sterile nutrient gel packets.