Does plasmid DNA mutate over time? - (Dec/10/2008 )

Hi Bioforumers,

What are the chances of plasmid DNA mutating if stored at -20C? Would there be multiple mutations? And how would that happen?!

Thanks a lot for any suggestions!

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The probability of spontaneous mutations occurring in the freezer is pretty low, as there's nothing to cause such a mutation. Why do you ask (Presumably you have found some mutations in a plasmid or insert, right?)?

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Nope, mutations do not occur within a plasmid while it is in a freezer. A plasmid in a freezer can actually survive for 2-3 decades.

However large BACs with a tandem repeat structure can get truncated by recombination once it has been retransformed back into the cell. I believe this is due to repair of BACs that get linearised during the extraction protocol

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