FAQ (veelgestelde vragen) - CRYO technologie
1. What is a cryogenic liquid?
The boiling point of cryogenic liquids (like nitrogen) is below -40° C at atmospheric pressure. Commonly the boiling point of these liquids is even lower than 40°C (e.g. liquid nitrogen: -196° C).
2. Is it safe to store Cryo.s in liquid nitrogen?
Liquid Nitrogen is in general not optimal suitable for the storage of freezing vials. The storage should be done above the liquid in the gas phase or in a -80° C freezer. The reason for this procedure is the following: The physical properties of the material change at these extreme temperatures like -196° C (boiling point of liquid nitrogen). A proper sealing system does not exist at this low temperature that would prevent liquid nitrogen to enter the vials. Greiner Cryo.s with internal thread and silicon gasket seal are the most suitable for the storage in liquid nitrogen. However, a guarantee that liquid nitrogen will not enter the vials does not exist. The infiltration of liquid nitrogen represents a safty risk for the following reasons: 1. While converting from liquid to gaseous aggregate state, nitrogen expands by factor 694. Remnants of liquid nitrogen in freezing vials could cause an explosion of the tubes. Therefore, it is essential to wear protective clothes like lab coat, safety goggles and gloves. 2. Contaminants like mycoplasms can survive in liquid nitrogen. That way one single contaminated culture is able to infect all other stocks in the liquid nitrogen tank.