Hey Stephanie, how are you? To answer your question, yes you can.  We just bought a freezer from a local supply store here, and it does the job, except ours is the frost free kind, which you want to avoid in order to keep temps stable. Hope that helps! 

 Hello Stephanie - if you are looking at long-term storage, you really need a -80.  Call me if you need more info.  

both are correct: buy a normal household freezer which allows to enable automatic defrosting, but for Long time storage I would also opt for a -80C, but his one wouldn´t come cheap!

Dear Stephanie,

I recommend to buy a scientific freezer, these are more stable (less temp fluctuations)   and for long term storage a -80°C is preferred.

I would agree that you need to be careful if selecting a home food freezer vs. a laboratory freezer. If you look at any cold storage equipment (freezers / refrigerators) for commercial use, including for restaurants, laboratories, etc., they are all significantly more expensive than home freezers. The reason for this is partially that they aren't mass produced the way that home freezers are, but it is also that the tolerances are tighter and this requires better components (which is why lab freezers simply aren't inexpensive, rebranded home freezers). A -20°C setting in a home freezer is more likely to vary significantly from that set point, and it will likely a looser temperature stability than a laboratory freezer. So, for instance, while a lab freezer set to -20°C may vary from -18°C to -22°C, a home freezer may end up varying from -12°C to -20°C. This isn't necessarily true for every given freezer, but it is more likely.

If you are going to consider getting a freezer made for home use, ensure you know the temperature stability of the freezer (how much it warms up before the compressor is turned on and how much it overshoots before it turns back off), what the temperature uniformity is (how much the temperature varies between different sections of the freezer) and what the temperature accuracy is (how much the actual temperature can vary from the temperature reading with it still meeting its specifications for quality purposes). All of these things are very likely to vary more than with a lab freezer, especially stability, since people aren't very sensitive to the exact temperature of their home freezers and turning the compressor on and off less frequently (and thereby increasing the range of temperatures the inside of the freezer experiences) leads to longer life, which the average person buying for a freezer their home is very sensitive to. These might not all be standard specs, but if you call the manufacturer or your supplier of choice, they should be able to get this information for you.

If you have any questions about laboratory freezers, we'd be happy to help.

https://labfreezers.net/

https://labfreezers.net/

Don´t worry and buy one from a "normal" household store, we´ve done this many times. Only if you need very low temperatures like -70C you wont find one in the "household " range, but in any other caeses there is no need to support a "suffering" industry!

We went through this exercise recently. Our objective was to keep the samples temporarily frozen in the lab until they can be shipped in ice packs for genetic testing. The lab freezer alone was of very big size for which we did not have requirement and also we did not have space in our lab. The combination of refrigerator and freezer did not suite our requirements. Two other issues were (i) The lab freezer was not available immediately. We had to wait 2-3 months. (ii) The price of laboratory freezer was 8-10 times higher than the combination of house hold refrigerator and freezer. We ended up buying a house hold combination of vertical split 50% refrigerator and freezer (-25 ̊C) available immediately in the market which is performing well for the past 2 months.

If you need an ultra-low temperature lab freezer, a company called ABM has one available (https://www.abmgood.com/lab-equipment/lab-freezer/Ultra-Low-Temperature-Lab-Freezer-528-L-Q5126.html)

For my needs in preserving liquid probiotic microbial cultures (in my case, I am lucky in that the primary microbial species in the culture being stored is one that happens to be very hardy and robust at freezing temperatures), I chose to use a nominal -20 degree C (-4.0 degrees F) freezer, and, for reasons of economy, after some extensive due diligence (research), I chose a 5.0 cu ft chest freezer sold for home use that was in stock at a local Home Depot (a home improvement retailer in the US) store. I set the freezer temperature control knob to the coldest setting (about 12.8 degrees F, or -25 degrees C) and secured it at that setting with gaffers tape. I then installed an inexpensive (less than $20) digital freezer thermometer on the outside of the chest freezer which also has a HIGH TEMP audible alarm that can be preset.

One precaution that I follow to ensure relatively stable interior temperatures in the chest freezer is that I have installed in the free space freezer (that is, space not taken up by cultures) about 2.5 cu. ft. of frozen gel packs. The frozen gel packs are stored at a higher point in the freezer interior than the HDPE plastic culture bottles to ensure maximum temperature stability of the culture bottles.

I installed the freezer on an unheated screened porch (my research lab is located in a temperate zone in the mountains on the East Coast of the US where outdoor temperatures range between -2 degrees F and 94 degrees F at the most extreme yearly). Incidentally, since my lab and home are located in a rural mountainous area subject to frequent power failures of commercial utility AC power, I have the freezer AC power set up to switch to a robust (uptime reliability is 9 nines) solar-assisted battery backup emergency power system if an utility AC power failure lasts for longer than ~3 hours or if the interior temperature of the freezer rises above -19 degrees C.

I have found in practice that this consumer-type chest freezer, which cost about $160 USD, and installed as noted above, has fit my needs perfectly. It keeps the contents at a relatively constant temperature which ranges between -9.0 degrees F and - 14 degrees F (-22.77 to -25.55 degrees C) as the internal thermostatic control switches the compressor on and off.

BTW, when it comes to consumer freezers, chest type freezers are far preferable to vertical shelf-type freezers with front doors, because the chest freezers are usually designed and constructed with better and thicker insulation on the walls and door/lid, and are usually designed to reach a lower temperature than vertical shelf freezers, and preserve the interior cold temperatures much more reliably when the door/lid is opened.

Of course, I would really prefer to have a lab freezer capable of reaching a storage temperature of -86 degrees C, but one of them would cost in the $6,000 price range, and would consume far more AC power! I am, of course, lucky in that I can get by with using the nominal -24 degree C consumer-type chest freezer for my probiotic culture storage purposes, and one thing that helps me, much as I mentioned above, is that the microbial species that I am storing is naturally very robust and stable at freezing temperatures, and I also take the step of adding several ingredients to the liquid culture prior to freezing to increase the viability and stability under storage at nominal -24 degree C freezer temperatures even further. As a result, I am able to store these probiotic liquid cultures for many years without serious degradation in count of abundance of viable microbes. On the other hand, a culture of a common probiotic species such as Lactobacillus sp. would likely survive less than one year at such temperatures (i.e., just below -20 degrees C)!