No matter how carefully you plan out your experiment mistakes are bound to happen from time to time. Reagents are accidentally placed into the wrong storage location, shipments are delayed and arrive later on Friday, and freezers can fail while packed with valuable materials. How can you tell what components are still usable? Today we will talk about some of the standard refrigerated and frozen reagents and how to tell if they can still be used after a storage mishap.
DNA samples:
Most DNA samples will instruct you to immediately refrigerate or freeze the samples upon receipt (carefully check the reagents and kit instructions if you are unsure). In general, QuickStrip™ DNA samples should be refrigerated, while bulk DNA in a microcentrifuge tube should be frozen. These DNA samples are highly purified and have been mixed with a buffer that enhances their stability. Because of this, the DNA will be shipped in a standard box and does not require refrigeration. In addition, this means that the DNA can handle extended periods of time at room temperature – up to a month at room temp should be fine without any decrease in the quality of the DNA sample!
Proteins:
Kits containing proteins should be frozen immediately after they arrive. However, similar to DNA, the protein samples are provided in a buffer that greatly enhances their stability. Most proteins will be stable for weeks at room temperature if necessary. In addition, experiments containing lyophilized (freeze-dried) proteins are even more stable.
Enzymes:
Many of our intermediate and advanced experiments contain enzymes, including restriction enzymes, proteases, ligase, polymerase, and many more. These reagents tend to be more sensitive and care should be taken to immediately place them into the refrigerator or freezer. Liquid enzymes are particularly sensitive – one to two weeks at room temperature should not impact the activity, but beyond that they will start to degrade. However, lyophilized enzymes are much more robust and can handle longer stretches of time outside of the ideal temperature.
Antibodies:
Antibodies are very fragile under normal conditions, and can quickly denature. It is important to store them in the refrigerator after they arrive and ensure that they spend as little time warm as possible. Fortunately, the majority of our experiments now use lyophilized antibodies which show a similar increase in stability as the proteins and enzymes discussed above.
Bacteria and other model organisms:
All Edvotek Bacteria is currently provided in lyophilized Bactobeads™. These bacteria should be refrigerated upon arrival, but can handle warmer temperatures for up to 1 month. Similarly, lyophilized virus samples can be stored at warmer temperatures without it impacting the quality of the results.
Other model organisms MUST be stored according to the included protocols. This includes C. elegans, insect cells, and Drosophila, which should be stored at room temperature. Ideally this would be in a location that is relatively stable, without large temperature swings at night or over the weekend. Note, even short durations at cold or hot temperatures can kill these model organisms. If you are ever in doubt, check under a microscope and follow the included instructions to ensure that the organisms are healthy.
While the above covers many of the reagents in our experiments, it’s impossible to explain every potential storage condition. As always, follow the instructions included on the reagents or experiment instructions for the best storage options. If you are still unsure, please reach out to our technicians at info@edvotek.com or 1-800-338-6835 with any questions!
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