A cryogenic storage dewar is a vacuum-insulated vessel designed to store biological or industrial material in or above liquid nitrogen at -196°C for extended periods. The term dewar derives from Sir James Dewar, who invented the vacuum-jacketed flask in 1892. Modern laboratory storage dewars apply the same fundamental principle at a range of sizes and specifications suited to the demands of IVF clinics, biobanks, research institutions, and clinical laboratories.
The vacuum jacket is the defining engineering feature of a cryogenic storage dewar. The space between the inner and outer walls of the vessel is evacuated to a high vacuum, eliminating heat transfer by conduction and convection through the wall. A multilayer reflective inner surface addresses radiant heat transfer. Together these mechanisms allow a well-made dewar to maintain liquid nitrogen at -196°C for days or weeks with minimal LN2 loss.
Evaporation rate, expressed in litres of LN2 lost per day under normal operating conditions, is the most operationally significant specification. It determines how frequently the vessel needs topping up, what safety buffer exists between top-ups, and what the lifetime LN2 consumption cost will be.
Storage capacity determines how many samples can be held in a single vessel. Capacity must be matched to programme volume with enough headroom for growth. Overcrowding a dewar increases access frequency and the associated LN2 loss and temperature excursion risk.
Neck diameter governs the trade-off between evaporation through the open neck and ergonomic access for sample loading and retrieval. Narrow neck designs minimise LN2 loss through the aperture but restrict access. Wide neck designs improve workflow ergonomics but accept a higher evaporation rate.
Cryogenic tanks represent the largest product segment with approximately 38.5% market share in 2025, anticipated to grow at 6.9% CAGR through 2034, reaching approximately USD 5.08 billion.
Liquid phase versus vapour phase configuration is a fundamental design choice. Vapour phase dewars hold samples above the liquid surface in the cold nitrogen vapour, eliminating cross-contamination risk through the liquid medium.
Vacuum integrity must be maintained throughout the vessel’s working life. Frost or condensation on the outer shell and an abnormally high evaporation rate are both definitive indicators of vacuum failure requiring immediate removal from service.
Cryolab supplies cryogenic storage dewars across a full range of capacities for IVF laboratories, biobanks, and research institutions. Browse the full dewar range or contact the Cryolab team for a specification consultation.
