Cryogenic storage at very cold temperatures is designed to provide an indefinite, if not nearly infinite, longevity to biological materials.
By reducing sample temperatures to below the glass transition phase of water (-132°C), all metabolic
activity comes to a halt. Storage below this temperature therefore offers the most secure form of long term cryo-preservation.
Storage in gas phase liquid Nitrogen provides a convenient way of storing samples at temperatures
below this transition temperature.
FluidX screw cap storage tubes are designed for long term sample storage at cryogenic temperatures, including storage in the gas phase of liquid Nitrogen.
Gas phase liquid Nitrogen temperatures have been typically quoted as between -150°C and -178°C, depending on the location and the distance away from the liquid nitrogen reservoir surface.
However, the latest generation of cryogenic storage systems are powered by liquid nitrogen in such a way to ensure a consistent temperature within the storage chamber, and can be as low as -195°C.
All FluidX screw cap storage tubes are fully compatible with this storage temperature and can be safely used for long term storage in this
environment. However, immersion in liquid nitrogen is not recommended for two reasons:
1. Liquid nitrogen is extremely pervasive.
If a tube cap is not completely and correctly tightened nitrogen may seep inside the tube. When the tube is then removed from storage this liquid nitrogen will instantly boil, expanding to over 700 times its liquid volume. This creates a significant risk of explosion and/or biohazard risk from aerosols.
2. Many researchers have noted that immersion in liquid nitrogen carries with it a significant risk of cross contamination from bacteria, viruses and DNA that can be present within the liquid Nitrogen.
Therefore, if required, snap-freezing is best achieved by immersing the tube in liquid nitrogen to a depth that avoids the nitrogen coming into direct contact with the tube cap.