[Taxacom] DNA preservation: -20C vs. -80C

[Gaurav Vaidya]

Hi Julian,

On 10 Jun, 2014, at 9:13 am, Julian Dupuis <jrdupuis at ualberta.ca> wrote:
> Our lab is currently lamenting the death of one of our -80C freezers, and
> we are debating whether to scratch the money together for another -80C, or
> move some of our DNA storage to -20C freezers. I have always been taught
> that -80C storage is best for DNA preservation, but don't have any personal
> experience to back that thought up. Additionally, our lab has had fine
> success with doing sanger and next-gen sequencing on material (both DNA and
> insect tissue) stored, at least for the short term (several years), at -20C.
> 
> Has anyone ever tested DNA storage at -20C vs. -80C for typical molecular
> phylogenetics/ population genetics approaches? Or does anyone have any
> experience that would support the mantra that -80C storage is superior to
> -20C? Any information, suggestions, or opinions would be greatly
> appreciated.

Here are some records of temperatures used to store DNA and other biological samples at CU Boulder and UC Davis: https://spreadsheets.google.com/spreadsheet/pub?hl=en&hl=en&key
sLDc2bsvPZCdHZsX05jaUVnM3NORmUwdl85MDFlS2c&single=true&gid=0&output=html

These records were made as part of the StoreSmart Lab Freezer Challenge, which aimed to reduce energy usage by keeping samples at the higher possible temperature. You can find out more about this initiative at: https://sites.google.com/site/labfreezercompetitioncuboulder/temperature-tuning/details-on-providing-info-on-biosample-storage--70c-or-warmer

cheers,
Gaurav