Validation of an Autoclave Procedure for Sterilization of Mouse (Mus musculus) Carcasses.

The sterilization of potentially infectious animal carcasses is an important biologic safety issue in animal facilities operatingas infection or quarantine barriers. However, the literature lacks a validated protocol. Here we describe the validation of anautoclave program suitable for daily use in a small rodent biocontainment unit. We evaluated several procedures for processing mouse carcasses in a standard autoclave. Heat sensors and biologic indicators were implanted inside the peritoneal cavity of dead mice, which were loaded at various densities into IVC cages or metal boxes. Heat sensors revealed broad differencesin temperature inside carcasses compared with the autoclave chamber. Achieving the appropriate sterilization temperaturewas considerably prolonged in carcasses compared with typical laboratory waste material. We show that for 5 cadavers placedwell separated inside an IVC, a modified program for mouse cage sterilization using 134 °C for 15 min is suitable. To sterilizeapproximately 1 kg of carcasses in autoclavable boxes, a period of 6 h is required to reach an effective temperature of 121 °Cfor 60 min at the center of the waste by using an autoclave program for liquids. In conclusion, we here validated 2 protocolsfor the sterilization of potentially infectious mouse carcasses, to ensure the application of efficacious procedures.