Internal transfer means the mice remain germ-free but are transferred to a different isolator or shipping container. This transfer uses the same principles as the cylinder deposition (Chapter 9).

An internal transfer refers to transferring mice between sterile isolators. The procedure is similar to those discussed in the chapters on supply cylinder deposition and shipping mice. Internal transfer is the safest way to transfer axenic mice. The most common reason to do an internal transfer is to expand an established breeding colony into a new, verified isolator.