A correctly charged dry shipper maintains an internal temperature between approximately -150°C and -190°C during transit. The exact temperature depends on the vessel design, the fill level of the sorbent matrix at the time of charging, and ambient conditions during transport. All of these temperatures are well below the critical biological threshold of approximately -130°C — the point below which cryopreserved samples enter the glassy (vitreous) state and biological activity effectively stops.
The temperature at which a dry shipper operates during transit is determined by how much nitrogen vapour the sorbent matrix releases and how effectively the vessel’s insulation retains that cold mass. A vessel with a degraded sorbent matrix — one that has been through many charge cycles — may have a reduced nitrogen retention capacity, which can narrow the margin above -130°C on longer journeys. This is why tracking hold time performance across successive charges is good laboratory practice, not just a precaution for new vessels.
Before every transfer using any model in the CryoStork range, perform the inversion test: hold the fully charged vessel inverted for 10 seconds and confirm no free liquid nitrogen exits. This confirms the charge is complete and the vessel is operating in the vapour phase as intended. For guidance on charging protocols or model selection for your specific transfer requirements, contact Cryolab or ask CryoGPT.
