Description_x000D_ General description_x000D_ Manufactured from an exceptionally clear, virgin polypropylene with a medical-grade silicone O-ring seal. These vials are designed for safe storage at temperatures as low as -196°C but should be used only in the gas phase of liquid nitrogen._x000D_ The specially formulated silicone O-ring ensures a positive leakproof seal at all temperatures. A unique base on the skirted vials locks them into place in the microtube locking work station (Z376809). Tubes can be autoclaved to 121°C in upright position with caps loosened. They also can be centrifuged up to 17,000 × g._x000D_ Packaging_x000D_ Caps and tubes are assembled in bags_x000D_ For non-sterile vials, caps and tubes are bagged separately._x000D_ For sterile vials, caps and tubes are assembled in bags.