Transporting biological samples at cryogenic temperatures is one of the most critical and most unforgiving logistical challenges in modern IVF and research laboratories. Get it wrong and samples are lost. Get it right and frozen embryos, oocytes and sperm arrive at their destination in exactly the same condition they left.
That is precisely what a liquid nitrogen dry shipper is built for.
Whether you are moving IVF samples between fertility clinics, shipping frozen donor sperm for an international programme, or transporting research specimens between institutions, this guide covers everything your laboratory needs to know before making a decision.
How a Dry Shipper Actually Works
The principle behind a dry shipper is straightforward. Unlike a standard laboratory storage vessel — such as the CryoNest® range used for on-site cryogenic storage — a dry shipper does not carry liquid nitrogen as a free liquid. Instead, the inner lining absorbs LN2 into its structure and holds it there, releasing it slowly as controlled vapour throughout transit.
This matters enormously for two reasons. First, there is no free liquid to spill if the vessel is tilted or handled roughly during shipping. Second and more importantly for international shipments the absence of free liquid nitrogen means the vessel qualifies as non-hazardous under IATA dangerous goods regulations, making it fully approved for air freight.
Samples are transported in the LN2 vapour phase, maintaining stable cryogenic conditions throughout the journey and protecting sensitive biological material from temperature fluctuations that could compromise sample integrity.
CryoStork Dry Shipper is designed specifically for the safe, secure and efficient transportation of biological samples in the liquid nitrogen vapour phase. It is available in capacities from 2 to 10 litres, accommodates round canisters, and keeps a compact, easy-to-handle form factor that makes it practical for laboratory staff to load, carry and dispatch without specialist handling equipment.
Its durable construction delivers reliable performance over time, whilst the lightweight design means staff can handle it safely without the physical strain associated with larger cryogenic vessels. The robust insulation maintains consistent LN2 vapour conditions throughout transit, reducing the risk of sample degradation regardless of ambient temperature or journey length.
The CryoStork is used by IVF clinics, fertility laboratories, research facilities and biobanks that need a dependable, repeatable solution for shipping biological materials domestically and internationally.
Key features at a glance:
Capacities from 2 to 10 litres to suit different shipment volumes
Round canister accommodation for compatibility with standard cryogenic storage systems
LN2 vapour phase storage for consistent temperature maintenance
Compact design for easy storage, handling and dispatch
Robust insulation for reliable performance across multiple uses
Easy loading and unloading of samples
CryoStork vs CryoNest – Understanding the Difference
This is the question we hear most often, and it is worth addressing clearly.
The CryoNest® range is built for static laboratory storage. The CryoNest® XL, for example, offers a 95-litre capacity that holds significantly more samples than a standard 47-litre tank without increasing its laboratory footprint. It maximises storage efficiency, capacity and ease of sample access — and is designed to sit in your laboratory providing reliable long-term cryogenic storage with extended hold times.
The CryoStork is built entirely for transport. Compact, lightweight and IATA compliant, it is designed to get samples from one location to another safely and efficiently — not to replace your laboratory storage vessel.
The simplest way to think about it: if the samples are staying in your facility, use a CryoNest. If they are leaving your facility, use a CryoStork.
Who Uses Dry Shippers?
The CryoStork is used across a wide range of settings wherever biological samples need to move between locations:
IVF clinics and fertility laboratories use dry shippers to transfer embryos, oocytes and sperm between clinics, to satellite collection points, and for international donor programmes.
Biobanks use dry shippers to distribute samples to research partners and receiving institutions across the country and internationally.
Research facilities rely on dry shippers to transport specimens between partner institutions, trial sites and analytical laboratories without compromising sample integrity.
Hospitals and NHS laboratories use dry shippers for inter-site transfers of biological materials where maintaining cryogenic temperatures throughout transit is essential.
Choosing the Right CryoStork Capacity
The CryoStork range runs from 2 litres to 10 litres. Choosing the right capacity depends on three practical factors.
Sample volume. How many straws, vials or carriers do you need to transport per shipment? Larger capacity models accommodate more canisters but add weight and bulk. Match the capacity to your typical shipment size rather than always defaulting to the largest available model.
Hold time required. How long is your typical transit from collection to delivery? Domestic UK shipments may only require 24-48 hours of temperature maintenance. International air freight shipments typically need five to seven days minimum and border delays can extend this further. Always choose a model with a rated hold time that comfortably exceeds your maximum expected transit time.
Handling practicalities. The CryoStork’s compact, lightweight design is one of its most practical features. For frequent shipments handled by a single member of staff, a smaller capacity model is easier and safer to manage than a larger vessel that requires two people to load and carry.
How to Charge a Dry Shipper Correctly
Correct charging is the single most important factor in achieving maximum hold time. A poorly charged shipper will not maintain temperature for its rated duration, which puts samples at risk. Follow these steps carefully.
Pre-cool the vessel. Pour a small quantity of liquid nitrogen into the CryoStork and allow it to pre-cool for ten to fifteen minutes before beginning the main charge. This conditions the absorbent lining and reduces thermal shock.
Charge slowly and steadily. Pour liquid nitrogen into the shipper at a controlled rate. The absorbent lining will draw in LN2 rapidly during the initial stages. Continue adding nitrogen as it absorbs — for a fully depleted shipper this typically takes two to four hours.
Check for full saturation. The lining is fully charged when liquid nitrogen no longer absorbs immediately and begins to pool briefly before being drawn in. At this point the material is saturated and ready.
Drain all free liquid. This step is non-negotiable. Pour out all remaining free liquid nitrogen and briefly invert the shipper to ensure complete drainage. Any free liquid remaining inside renders the shipper non-compliant for air transport and creates a spillage hazard during handling.
Allow twelve hours to stabilise. Leave the charged and drained shipper undisturbed for at least twelve hours before loading samples. This allows the internal temperature to equalise fully and ensures you achieve the maximum rated hold time in transit.
Load, seal and label. Load your samples using appropriate cryogenic forceps and personal protective equipment, seal according to the manufacturer’s instructions, and label clearly with sender details, recipient details and — where required — IATA documentation.
Shipping Biological Samples Internationally by Air
The CryoStork’s IATA compliance makes it the practical choice for international biological sample logistics. A few things worth knowing before your first international shipment.
Classification. Dry shippers carrying biological samples are typically classified under IATA Packing Instruction P650 for Category B biological substances. The exact classification depends on the nature of the contents — confirm with your freight forwarder before booking.
Documentation. Always include a clear description of the contents, sender and recipient contact details, and any regulatory paperwork required by the destination country. For IVF samples, the receiving clinic may need import permits or regulatory authority approvals arranged in advance.
Airline acceptance. Not every airline accepts biological specimens as cargo. Always confirm with the carrier or freight forwarder before booking. For high-value or irreplaceable IVF samples, using a specialist cryogenic courier service is strongly recommended over general freight.
Temperature monitoring. For high-value shipments, include a temperature indicator or electronic data logger inside the shipper. This provides documentary evidence that samples remained at cryogenic temperatures throughout transit — increasingly important for regulatory compliance and chain of custody records.
Order CryoStork From Cryolab
Cryolab supplies the full CryoStork Dry Shipper range to IVF clinics, fertility laboratories, research facilities and biobanks worldwide. Every CryoStork is supplied with full compliance documentation for airline, freight handler and customs requirements.
For laboratories requiring on-site cryogenic storage, the CryoNest® series offers a full range of high-efficiency storage vessels from standard capacities up to the 95-litre CryoNest® XL.
View the full CryoStork Dry Shipper range
Not sure which model is right for your requirements? Contact us through the website and our team will help you select the right vessel for your specific shipment needs.
Follow Cryolab Ltd on LinkedIn for the latest product updates.
Frequently Asked Questions
What capacity CryoStork dry shipper do I need? The CryoStork is available from 2 to 10 litres. Match the capacity to your typical sample volume and required hold time. For most single-clinic IVF transfers a smaller capacity model is sufficient, whilst larger capacity models suit biobanks and research facilities with higher shipment volumes.
How long does the CryoStork maintain cryogenic temperatures? Hold time varies by model and ambient conditions. Always check the rated hold time for your specific model and ensure it exceeds your maximum expected transit time by a comfortable margin.
Can dry shippers be reused? Yes. Allow the CryoStork to warm fully to room temperature before storage and recharge with liquid nitrogen before the next shipment following the charging steps above.
What is the difference between the CryoStork and the CryoNest? The CryoNest® is designed for static on-site laboratory storage with a 95-litre XL model offering maximum capacity without increasing laboratory footprint. The CryoStork is designed for transport — compact, lightweight and IATA approved for air freight with no free liquid nitrogen.
Does Cryolab ship worldwide? Yes. Cryolab supplies CryoStork dry shippers and the full CryoNest® storage range to IVF clinics, hospitals, research laboratories and biobanks worldwide.
Top comments (0)