Lab freezers are very different from domestic products. While most people perceive this difference to the size of the freezer, it is important to know that lab freezers are not simply bigger versions of the freezers that we have at home. Just like everything else in a laboratory, the freezers there too are devices that have to be specifically manufactured in order to be able to maintain a specific and constant temperature. Lab products are used to store critical elements and materials, many of which are either dangerous or need to be in controlled temperatures to avoid damage.
Household freezers normally maintain a temperature that ranges between 0 to -10 degrees Celsius, while a lab version can have a temperature going down to almost -85 degrees Celsius.
These are used for a variety of purposes which primarily include storing samples of tissue and serums, RNA samples, bacteria strains, protein extracts and DNA. In hospital labs these can be used to store various organs and blood while in pharmacies these are used to store medicines. Freezing these samples makes sure that their quality is preserved and is stable over long periods.
The laboratory freezer is built to look much like the home freezer. Shelves in the unit and the door and rubber gaskets that prevent the cool air from filtering out form the basis of both these types of refrigerators. The standard temperature that these products are kept at is between -15 to -25 degrees Celsius and come with an LCD display that enables one to keep a watch on the standard temperature of the freezer without having to open the door. Much like domestic freezers, these too can be locked.
Most low temperature lab freezers have a storage capacity of 31.4 cu feet and have the ability to store up to 70,000 lab samples in 35 inventory racks. They also have the ability of reducing the temperature going down to almost -86 degrees. Another type of laboratory freezer is the super low temperature model. This has the capacity to go down to cryogenic temperatures of almost -150 degrees Celsius without using liquid nitrogen. The liquid nitrogen version has a capacity of reaching -190 to -196 degrees Celsius. There are some products that have storage capacity of 1000 cubic feet and are called mini walk in freezers. However, such large models cannot reach very extreme temperatures because of the constraint in size.
When buying a freezer of this type what needs to be considered is what substance will be kept inside it. Delicate and dangerous samples require more attention and care while storing. The choice is also dependent on the type of space that is available to keep it. A chest freezer has a larger footprint than an upright product despite having the same amount of internal volume. Also, chest products work better in retaining cold air than the upright ones when the door is opened. These chest freezers also go back to the original set temperatures quite fast in case the door is left open for long. However, upright versions are easier to use as locating samples is far easier in them.