The role of liquid nitrogen in biorepositories
Biorepositories rely on liquid nitrogen (LN₂) to preserve biological materials at cryogenic temperatures (-196 °C or below), which has been called the "gold standard of preservation" across the industry for many years. At these extreme temperatures, molecular motion nearly stops, effectively halting biochemical reactions that would otherwise degrade DNA, RNA, proteins, and cellular structures.
Modern cryogenic freezers use LN₂ either in liquid immersion or vapor-phase systems.
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Liquid-phase freezers keep samples fully immersed in LN₂, ensuring rapid cooling and ultra-low temperatures.
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Vapor-phase freezers maintain samples in a cold nitrogen vapor above the liquid surface, reducing contamination risks while maintaining temperatures typically below -150 °C.
Both technologies are essential for the long-term preservation of high-value biological samples, ensuring reproducibility in research and the viability of clinical and genomic materials.
What kind of samples get stored in liquid nitrogen?
Cryogenic storage with liquid nitrogen supports a wide range of research and clinical applications. Typical materials include:
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Human samples: blood, plasma, serum, tissues, stem cells, sperm, embryos, cord blood, and organoid cultures.
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Animal and veterinary samples: cell lines, embryos, gametes, and genetic material from research animals or endangered species.
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Microbiological and plant materials: microbial strains, yeast, fungi, seeds, and plant cells for biodiversity and agricultural studies.
These materials can remain viable for years or even decades if properly maintained.
Why nitrogen supply matters for biorepositories and biobanks
Reliable LN₂ availability is a critical infrastructure element in any biobank. A sudden supply interruption can jeopardize years of collected material and research investment.
An on-site LN₂ generator offers several key advantages compared to frequent deliveries:
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Reduced dependence on external deliveries: minimizing logistical delays and transportation costs.
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Lower long-term cost per litre, when daily consumption is consistent.
- Operational flexibility and resilience: ensuring cryogenic temperatures are maintained even during supply-chain disruptions or transportation delays.
By producing LN₂ directly from ambient air, these systems convert nitrogen gas into liquid through cryogenic cooling and store it in an integrated tank, ready for use in cryofreezers.
Challenges of traditional LN₂ supply
Despite its importance, the conventional supply model (delivery via tanker trucks or portable dewars) comes with several challenges:
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Supply Chain Disruptions:
External supply depends on industrial gas distributors and global logistics. Weather events, geopolitical tensions, or transport strikes can delay deliveries. Even short-term interruptions risk warming events that compromise biological samples. -
Transport Issues:
Facilities in remote or restricted-access areas often face limited delivery frequency or lack of bulk delivery infrastructure. Smaller biobanks in hospitals or research centers may depend on manual dewar handling, which is labor-intensive and less reliable. -
Transportation Losses:
LN₂ naturally evaporates during transport and transfer. Boil-off losses can be significant, especially for smaller users, leading to inefficiencies and higher effective costs per litre. -
Safety Risks:
Handling bulk LN₂ requires training and proper ventilation. Refill operations in confined spaces carry asphyxiation hazards due to oxygen displacement, as well as risks of frostbite or material embrittlement.
Liquid nitrogen generators for biorepositories
Noblegen produces autonomous, reliable liquid nitrogen generators that are easy to set up and operate, requiring minimal training for laboratory staff.
On-site generators are highly effective, reducing bulk storage time and the associated boil-off losses, including those that occur during transport and decanting.
The Triton range offers an ideal plug-and-play solution with a 10-20 L/day output, perfect for applications requiring small, consistent top-ups. Simply connect the power and press ‘Start’ for the machine to automatically produce liquid nitrogen, ready for use. The Triton generators are easy to maintain and allow for quick, efficient filling without the need to transfer from bulk storage.
The Callisto range includes larger-capacity, dual-cabinet generators designed to support requirements of 20–60 L/day. Available in air-cooled or water-cooled configurations, these generators are among the most user-friendly on the market, featuring an innovative touchscreen display, real-time diagnostics, and a compact footprint.
As research expands and sample preservation demands grow, ensuring uninterrupted cryogenic storage is more important than ever. For smaller laboratories and biobanks, on-site LN₂ generation offers a practical and reliable alternative to traditional delivery-based supply.
By producing liquid nitrogen as needed, facilities can reduce logistics complexity, enhance sample security, and achieve long-term cost stability, empowering biorepositories to operate safely, efficiently, and independently.