Storage at these low temperatures ensures that samples can be stored long term and limits the risk of deterioration.
There are several types of freezers that can be used for storing biological materials, the most common being mechanical freezers and liquid nitrogen freezers.
Mechanical Freezers
Simply put, a mechanical freezer is what the majority of us use domestically in the form of an upright or chest freezer.
Using arefrigeration-system, mechanical freezers are able to maintain temperatures between -20 and -80 °C with some models able to store as low as -150°C. However, at this temperature the mechanical freezers will use large amounts of energy and give out a lot of heat.
When it comes to the storage of biological samples, mechanical freezers are a viable option, depending on the type of material being stored. Samples such as cells, tissues and enzymes can be safely preserved in a mechanical unit.
However, if the intended application is long term storage, mechanical freezers do pose some potential problems for users:
- Limited temperature range: The majority of mechanical freezers are only able to maintain temperatures between -20 and -80 degrees, meaning that they are unsuitable for many types of samples. Even though some operate as low as -150C, these are not energy or cost efficient.
- Cost efficiency: Despite the initial purchase price of the unit being lower than other freezer types, the running costs associated with the upkeep and energy consumption of mechanical freezers can add up quickly. In addition, mechanical freezers generate significant amounts of heat, meaning that HVAC (heating, ventilation, and air conditioning) and temperature monitoring systems are required to limit heat access within the storage lab which results in additionaloperating costs.
- Higher risk of equipment failure: Without regular maintenance and servicing (which can be costly) a mechanical freezer runs a greater risk of malfunction, meaning that valuable contents can be lost should the freezer stop working due to technical issues such as a defective thermostat or a faulty compressor.
- Sample security: In some installations, spare mechanical freezers are kept running despite being empty, ensuring that they are ready for use in the event that a unit containing samples should fail, or require de-icing. Also, in the event of a freezer failure, you only have a matter of hours before the temperature inside the freezer rises to critical temperatures.
- Storage capacity: Typically, a mechanical freezer is limited in terms of storage capacity, meaning that for facilities that store large volumes of samples, more units are required.
- Environmental impact: For those looking to minimise their carbon footprint, the substantial energy consumption required for mechanical freezers does not make them a suitable choice. Additionally, the end of life disposal of mechanical freezers is also potentially hazardous to the environment due to their use of harmful refrigerant gases.
Based on the factors mentioned above, it may be worth considering an alternative to traditional mechanical freezers to improve both the sample safety and cost efficiency of your laboratory storage operation - a liquid nitrogen freezer could be the perfect solution.
Liquid Nitrogen Freezers
Liquid nitrogen freezers mitigate many of the issues presented by their mechanical counterparts.
Although the initial purchase cost of liquid nitrogen freezers may seema more expensive option, the overall running and maintenance costs throughout the lifetime of the freezers make it far more economical in the long term.
Unlike mechanical and ultra-low temperature freezers, which rely on electrical refrigeration systems, liquid nitrogen freezers require far less continuous energy input to maintain temperature. This is due to the fact that their coolant properties come from the liquid nitrogen itself in the form of either liquid or vapour.
With their specialised insulated tanks, liquid nitrogen freezers are a far more suitable option for the long-term preservation of biological samples as well as having a relatively low carbon footprint, which is why they are often the preferred option for laboratories, medical facilities and commercial cryostorage facilities.
Liquid nitrogen freezers provided by Air Products are designed to suit a wide variety of applications and facilities:
- MVE HEco Series: Retain temperatures as low as -190 degrees Celsius at the top of the inventory, ensuring optimal safety for all samples in storage. The MVE HEco features a high efficiency vacuum insulation system with a low evaporation rate. This reduces liquid nitrogen usage, meaning fewer refills are required, resulting in reduced gas consumption and liquid nitrogen refills. Available in a range of capacities and providing ease-of-use with its intuitive touch screen interface, the MVE HEco series is a popular choice for laboratories and biobanks.
- MVE Series: Available in storage capacities ranging from 5,200 - 39,000 2ml vials, the MVE Series provides efficient usage of liquid nitrogen and maximum storage density. Equipped with a secure lockable lid to provide increased protection for valuable samples, these units are renowned for their reliable performance and energy efficiency.
- MVE Variō: The MVE Variō Series cryogenic freezers are the innovative and energy efficient alternative mechanical freezers as they operate between -20°C and -150°C with only 1% of the energy consumption.
The MVE Variō Series cryogenic freezer significantly reduces the possibility of sample contamination via contact with liquid nitrogen, while providing the safety margin and consistent temperature profile, even with the lid open, that is associated with liquid nitrogen-based cryogenic freezer storage. The MVE Variō Series cryogenic freezers are able to provide all of this with approximately 70% overall operating cost savings when compared to the leading mechanical freezers. In addition, the Variō emits no heat, thus, negating the need for high-cost HVAC systems.
The All-in-One Cryogenic Freezer Specialists
Air Products is an industry leading supplier of cryogenic freezers and storage solutions to suit operations in a range of industries. Offering services such as gas supply and delivery as well as project management and room design helping you to design and install a modern and efficient cryoroom that will keep up with current and future demand.
We are also the only industrial gas company who manufactures liquid nitrogen in the UK, which is compliant with the new Medical Device Regulation.
If you require more assistance choosing the right liquid nitrogen storage for your facility, you can use our innovative
product selector guide to find the model that best suits you. Alternatively, if you'd prefer to discuss with one of our experts, please contact us on
0800 389 0202 or
submit an enquiry here.
