Microtiter plate directed DNA degradation - Why is DNA on one plate degraded while intact on the next? (Sep/02/2010 )

I've extracted genomic DNA and stored them in 15 microtiter plates. they have all been freezed and if I thaw the samples and run test samples on a gel it seems to be degradation of DNA on several plates, in random plate order. the starting tissue and DNA samples have all been treated identically. How can DNA on one plate completely degrade while DNA on the neighbor plate is intact and working?

What buffer is the DNA stored in? Storage in TE will prevent most degradation, while water only storage allows many bad things to happen to DNA, especially if slightly contaminated with DNAses from your fingers, e.g.

DNA is stored in the MagNA Pure LC elution buffer from Roche. roche hides information about buffer's content deep down in their vaults so the only info I have about the EB is that it the bottle has a yellow cap

I've also thought about DNase from fingers, but I think it's strange since DNA prepared in parallel plates are perfectly intact.... Maybe it's a bad summer karma or something haha.

If I were doing the experiment, I'd drop that bottle in the trash and replace it with TE. But I'm that kind of guy. Or dilute your final DNA sample 1:1 with TE following elution and before storage. If robotic, you could load the elution plate with 1 volume of TE before elution.