MAP testing tissues and cell lines prior to allowing them access to the experimental rodent colonies is absolutely essential in preventing these problems. The use of murine sera presents additional problems beyond those of using cultured cells and tumors. Guidelines for testing of biologicals must be expanded to include all potential sources such as sera. We do this to expedite research and to avoid the additional costs for quarantine. We justify direct access for these animals based on the vendor's reputation and upon health reports provided by the vendors.
Some institutions occasionally test a few mice from each vendor.
A quick survey reveals that animals arriving from the same four or five vendors are placed directly into animal rooms in most institutions' animal facilities. Notably, the vendors whose animals are given direct access to our facilities have extremely elaborate protocols for mice entering their large breeding facilities and do not ever allow mice from other vendors to enter their animal rooms without undergoing quarantine. Our practice of allowing direct access should be re-evaluated in light of the irreplaceable nature of today's rodents. Another commonly ignored recommendation is the recommendation that embryos of all valuable strains of mice should be cryopreserved. It takes time, money and discipline to accomplish this task.