What are liquid cryogens and why is liquid nitrogen the preferred choice for biological storage in IVF and biobanking?
Liquid cryogens are substances maintained in liquid form at temperatures below -150°C. The group includes liquid helium (-269°C), liquid argon (-186°C), liquid oxygen (-183°C), and liquid nitrogen (-195.8°C). For biological storage in IVF, andrology, and biobanking applications, liquid nitrogen is the standard for three reasons: it is chemically inert and non-reactive with biological material, it is produced in large quantities at relatively low cost compared to other cryogens, and its boiling point of -195.8°C sits well below the critical -130°C threshold at which biological degradation effectively stops.
Liquid oxygen and liquid argon are occasionally found in industrial cryogenic processes but are not used for biological storage – liquid oxygen presents serious fire and explosion risk in laboratory environments. Liquid helium is reserved for applications requiring temperatures below -200°C, typically superconducting magnets and specialist physics research. For IVF laboratories specifying cryogenic storage vessels or dry shippers for specimen transport, liquid nitrogen is the correct and only appropriate choice. The correct PPE for liquid nitrogen handling is mandatory for all staff – contact Cryolab for a full safety equipment specification.
