well the dna we used never touched the inside of a cell; plain dried dna is very stable, evidenced by the ability to sequence 10's of thousands of years old samples stored in decaying flesh (albeit with some errors).
A bit of support to that: it used to be common to send plasmids (circular strand of DNA) to people on paper. You'd take a drop of the plasmid, put it onto the paper, and let it dry. When the recipient got the card in the mail, they'd cut out around your dried plasmid and put it back into water. It would be perfectly functional, if needed.
If you needed more, you could then transform E. coli with the plasmid and let them do the work for you.
I don't know if this is done very much anymore, but this helps to show just how robust DNA can be. I want to say that a few years ago, someone tried to sell our lab an archival tool for DNA that was essentially this. You dried your DNA samples onto blotting paper in a grid, then when you needed a sample, you could go back and reconstitute by punching it out of the paper.
