Inspired by the post about extracting pet DNA, how long would genomic DNA be stable for in a -20°C freezer? It is common practice to store DNA (double-stranded, plasmid) in a -20°C freezer in the lab, but would genomic DNA last longer in a -80°C freezer? With either method, how long would it be stable for?
If the DNA is pure, it should last quite a long time. If there are enzymes and other biological molecules in there, -80C will work much better.
I think you could keep pure DNA at -20C practically indefinitely.
Purity is the main issue there, also pH stabilized, sealed properly, etc. That makes all the difference.
You can store your DNA for 1 week at -4C and for one month at -20C but with storing DNA over these period of time there is a deduction of 10-15% of yield from your DNA sample.