"Dewar" in the laboratory can refer to very different things — from the small bench flask holding liquid nitrogen for snap-freezing to the 500-liter biobank tank storing cell lines for decades. That confusion has real consequences when it leads to the wrong equipment choice for the wrong application.
Here is the overview that cuts through it.
A Dewar vessel (named after Scottish physicist and chemist Sir James Dewar) is a double-walled, vacuum-insulated container that maintains the temperature of its contents for a defined period. The vacuum between the walls reduces heat conduction and convection; a radiation shield minimizes thermal radiation.
In cryogenics, Dewar vessels are used to store and handle liquid nitrogen (–196°C), liquid helium (–269°C), and other cryogenic fluids.
The smallest and most common form in laboratory settings. Typically 1–10 liters, glass or stainless steel.
Applications: Holding LN₂ for snap-freezing (immersion in liquid nitrogen), cryosectioning in histology, cooling samples during handling steps.
Not suitable for: Long-term biological sample storage — lab flasks have insufficient hold time and no sample inventory system.
Wide opening, 5–50 liters, often without a lid or with a loose stopper. Designed for direct access to samples in liquid nitrogen.
Applications: Short-term LN₂ work reserves in the laboratory, LN₂ transfer, manual snap-freezing.
Not suitable for: GMP sample storage — no temperature control, no monitoring, no audit trail.
These are the actual cryogenic storage devices — vacuum-insulated tanks with lids and sample rack/cassette systems. Designed for long-term storage of biological samples at –196°C (liquid phase) or –180°C (vapor phase).
The Consarctic® product series:
Key Consarctic® tank feature: Eccentric tank opening — reduces the evaporation surface and cuts LN₂ consumption by up to 30% compared to conventional designs.
Not a storage vessel, but a transport vessel. LN₂ is bound in an absorbent carrier material — no free liquid nitrogen, IATA-compliant for air freight. (Full article: Cryogenic Sample Transport with ASR+ Dry Shippers.)
Smaller, portable cryogenic tanks for use outside the laboratory — for example, mobile collection units in reproductive medicine or transplantation. Compact, impact-resistant, ergonomic handles.
| Criterion | Decision guidance |
|---|---|
| Application | Storage vs. transport vs. lab work — determines type |
| Sample form | Vials vs. cryobags → ABV+/ABS+/BSD+ vs. BSF+ |
| Capacity | How many samples, scaling over what timeframe? |
| GMP requirement | Monitoring, IQ/OQ/PQ, audit trail needed? |
| LN₂ efficiency | Opening design, hold time, consumption |
| Maintenance burden | Service network, spare parts availability |
"Dewar" is the general term for vacuum-insulated vessels for cryogenic fluids. "Cryogenic tank" is used specifically for storage devices for biological samples. In lab parlance, "Dewar" describes small bench flasks or LN₂ working vessels; "cryogenic tank" refers to storage equipment with sample rack systems.
For IVF and reproductive medicine: Consarctic® ABV+ and ABS+ series. These tanks are designed for cryovial storage in reproductive medicine settings. BSD+ and BSF+ series are not intended for IVF applications.
Depends on type and size. Small lab flasks (1–5 liters): a few hours to a few days. Medium storage tanks: 1–4 weeks. Large Consarctic® BSD+ tanks: several weeks to months depending on payload and opening frequency. The Consarctic® Monitoring-System data logger displays fill level and temperatures in real time.
No. Wide-neck laboratory Dewar flasks are not suitable for controlled long-term storage of biological samples — insufficient hold time, no sample rack system, no temperature monitoring. They are working vessels for short-term LN₂ needs at the bench.
Cryogenic Dewar containers and cryogenic storage tanks are not interchangeable terms — they describe devices with very different properties and use cases. The right choice starts with a clear answer to: what is being stored, for how long, under what regulatory requirements?
Consarctic GmbH offers the full product range — from the IVF-optimized ABV+ to the large GMP tank BSD+ — and advises on selection.