What Is the Difference Between Cryo Tanks for Storage and for Transport?

Cryo tanks used for static laboratory storage and cryo tanks used for sample transport operate on the same cryogenic principle but are designed for fundamentally different operational conditions. Selecting the wrong type for a transport task is one of the most common equipment errors in IVF sample logistics – and one of the most consequential.

How does a static storage cryo tank work?

A static storage cryo tank – a liquid nitrogen storage vessel – holds samples immersed in liquid nitrogen or suspended in the nitrogen vapour above the liquid surface. Liquid nitrogen is replenished on a scheduled basis, typically weekly or more frequently depending on the vessel’s static evaporation rate. Static storage vessels are designed for laboratory environments: they are not intended to be tipped, inverted, or transported over distance.

How does a transport cryo tank (dry shipper) work?

A dry shipper cryo tank charges liquid nitrogen into a porous internal matrix that holds the nitrogen in an absorbed state. During transport, the vessel releases nitrogen as vapour, maintaining the internal temperature at approximately -190 degrees C without free liquid nitrogen. This makes the vessel safe for road, courier, and air transport. IATA regulations prohibit the air transport of vessels containing free liquid nitrogen.

What is the hold time difference between storage and transport cryo tanks?

Static storage cryo tanks have hold times measured in weeks, and some large-format vessels can hold their liquid nitrogen charge for several months under static conditions. Dry shippers have hold times measured in days – typically 5 to 14 days depending on the model, the ambient temperature, and the frequency of access. Hold time must be verified for each vessel before any transport mission.

A laboratory that ships embryos in a standard storage dewar instead of a charged dry shipper is not just breaking IATA regulations – it is transporting samples in a vessel not designed to maintain cryogenic temperature during movement. The two vessel types are not interchangeable for transport.

Cryolab supplies the CryoStork V3 and CryoStork V10 dry shippers for IVF sample transport. Full details at cryolab.co.uk/product-category/dry-shippers/.