Hi all,

 

I extracted DNA and now I have a stock solution in TE buffer and two aliquots in water. How is it better to store all these solutions since I need to use it for long periods of time? Freezer or fridge?

 

Thank you

Put it in the freezer.

Because freeze-thaw cycles can shear DNA, if you're using it a lot, keep it in the fridge. If it's medium term storage, -20, and I keep my long term stored samples in the -80.

Actually I think that for a number of reasons the shearing due to freeze-thaw itself is only a secondary concern, but rather minute impurities tend to do the damage during the warm-up phase. In practical terms, there is not difference, of course. For extremely long storage (years to decade) I found DNA to be quite stable (at least whole bacterial chromosomes as well as plasmids) as precipitated under ethanol at -80C or carefully freeze dried.

I presume that this is not the scope being asked, though.

As a general rule when I freeze a protein, I try to freeze it quickly. I would imagine that some of the same considerations apply to freezing DNA.