Hi!

First I apologize for my english.

I electroporated a vector (containing 3 repeated regions of 250bp) in bacteria DH5a. I think that normally, DH5a are known to have a mutation in RecA that permit to avoid rearrangement of the plasmid. But the bacteria recombine the repeated regions of my plasmid and I obtain a plasmid of abberant size. So I search a strain that do not cause rearrangements or deletions within plasmid DNA. Can someboby help me?

 

Thanks a lot

Have a good day

Have you checked the plasmid before transforming them into DH5alpha?

While there are other RecA- strains, like e.g. TOP10, I am not sure why the outcome should be different to DH5alpha (as it already carries the relevant mutations).