Designed for safe storage at temperatures as low as -196 °C (but should be used only in the gas phase of liquid nitrogen). Autoclavable at 121°C. Sterilized by gamma radiation and packaged in unique tamperproof, resealable, safety-lock bags of 100†. Skirted tubes have a locking base for easy one-hand operations and only 1 1/4 turn of the cap is sufficient to screw the cap on the vial. Closure* and vial are both made of polypropylene having the same coefficient of expansion, ensuring an equally secure seal both at room temperature and at low cryogenic temperatures. Tubes have a white marking area, they can be color coded with a Capinsert™ (Series 17-T312) and are compatible with most storage systems. Only the non-skirted vials can be centrifuged up to 17,000 x g.