Shear-induced damage of plasmid by vortexing - (Mar/29/2012 )

Hi everyone

I have a general question regarding handling of plasmid DNA.

What's the best/most optimal way to mix plasmid DNA? By vortexing, by inverting, by pipetting up and down, or???

And following this question: does vortexing damage plasmid DNA? If yes, does it concern all sizes of plasmids, or only concern plasmid larger than a certain size?

Would be great to get your answers/experience.

Thanks a lot!

If you mean isolated plasmid DNA (i.e. not during the extraction process), then any mixing will work fine.

Plasmids should not be damaged by any of the mixing methods you mention, they are too small. I don't know the size cut-off, but in theory at least, bacterial genomic DNA can be sheared by vortexing.