MTC Bio Internally Threaded Cryogenic Vials offer unparalleled protection for long-term storage of biological materials in even the harshest of environments, with their thick-walled tubes with silicone O-rings able to maintain a secure seal at temperatures as low as -196°C. Sterilized by gamma irradiation, these vials are designed to hold, store and preserve a range of biological materials for extended periods of time. The self-standing starfoot base ensures a secure fit with an included rack, allowing easy installation and removal with one hand.