For direct use as template in PCR runs. Chelex 100 5-10% w/v extraction. Without listing the whole protocol, in the end the supernate is decanted off and then stored at 4°C. I was under the impression that this could be stored and later used almost indefinately but two of four samples extracted several months back failed to produce a product (when it was known they should have).

Assuming no mistakes were made and the reactions were the same, is there a technical reason the template would degrade to an unusable point?

Is there a rule of thumb about how long it can reasonably be expected to last?


My rule of thumb for DNA samples (in TE or water) - if I have plans to use it that week, I store at 4C. If I plan on using it within a month, I store at -20C. If I'm not sure when I will use it, I keep multiple aliquots at -80C. DNA can degrade by acid hydrolysis in water, because of contaminating nucleases in the sample, and by multiple freeze/thaw cycles.

  • $\begingroup$ Is there any long term storage option at room temperature? biology.stackexchange.com/questions/2231/… -Thanks! $\endgroup$ – Registered User May 11 '12 at 12:28
  • $\begingroup$ DNA has a half-life of over 500 years under perfect circumstances. However, DNA degrades over time, and when kept in solution, it is difficult for there to be exactly 0 microbes, DNases or chemicals present which can hydrolyze the helix. It degrades over time and old DNA samples kept even at -20C very frequently show poorer results, especially when it is thawed repeatedly. Primers can also degrade gradually at room temperature, etc. $\endgroup$ – S Pr Aug 7 '18 at 13:10

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.