Cryogenic is the production or use of very low temperatures; therefore, cryogenic storage utilizes low-temperature liquids to maintain the condition of a substance, such as liquid nitrogen, liquid oxygen, liquid hydrogen, liquid helium, and Liquefied Natural Gas (LNG).
Uses of Cryogenic Storage
For the pharmaceutical, biological, and consumer good fields, cryogenic storage, or cryostorage, typically uses liquid nitrogen (or LN2) to preserve ingredients, samples, and materials at temperatures as low as -196°C.
Liquid nitrogen is ideal for preserving biological samples, including blood, platelets, plasma, and tissue, for long periods. In temperatures below -130°C, the process of cryopreservation preserves biological materials by cooling them to extremely low temperatures in order to stop all biological activity. When the movement and biological processes of cells freeze, degradation and damage are prevented to allow for long-term storage.
For transporting materials, cryogenic transport services can vary depending on the size of the shipment, distance, and storage temperature needed. One common option for transport is dry shippers, which are designed to safely transfer materials via ground or air freight at cryogenic temperatures. Some dry shippers can maintain temperatures for over two weeks, with advanced features like GPS location tracking and real-time temperature monitoring.
How Cryogenic Liquid Nitrogen Storage Tanks Work
Cryogenic liquid nitrogen storage tank types vary. The smaller, more portable models designed for transport hold temperatures for a short length of time compared to bulkier versions meant to be kept on-site for the long-term storage of many samples.
Dewars are a type of storage tank for liquid nitrogen that typically have two or more walls, and are designed for vacuum insulation similar to thermos bottles. This vacuum insulation is to ensure the container is insulated from all three sources of heat transfer methods (convection, conduction, and radiation) to maintain low temperatures.
Liquid nitrogen storage tanks store in the liquid phase and vapor phase, with some tanks offering both in the same system.
When materials are stored directly in the liquid phase of liquid nitrogen, there is no temperature gradient, and samples are maintained at -196°C. However, since samples are directly in the liquid nitrogen, containers must be properly closed and expertly handled to prevent cross-contamination.
When stored in the vapor phase, temperatures can range based on proximity to the liquid nitrogen source. Many cryogenic storage tanks set a limit to maximum temperatures, such as -150°C. While there is temperature variation, the vapor phase reduces the risk of contamination as samples are not stored directly in the liquid.
Cryogenic Freezer Services
SciSafe provides cryogenic storage for your irreplaceable biopharmaceutical materials in the liquid phase and vapor phase of liquid nitrogen. Contact us today to speak with our team of experts to learn how we can provide secure and compliant cryostorage solutions.