removing nucleic acids from extracts

[Torsten Boerchers]

satish at a.chem.upenn.edu (Satish Nair) wrote:
..
>>I've had very little luck with DNases. I 
>>know there must be a straightforward way to remove nucleic acids 
>>from extracts, but I'm having trouble finding one.
>>Any suggestions would be appreciated.
>
>Neutralized polyethyleneamine (Burgess, Meth. ENzymol. 208, 3) will
>precipitate out DNA (1/10 volume of 5% solution works).  You have to
>get rid of the excess PEI (MW 50,000) and ammonium sulfate pptation of your
>protein should seperate the protein from excess PEI).  I'm sure there is
>a better way to do the latter part but I haven't spent time thinking too
>much about it.
>
>Strep. sulfate should also work?
>
>satish nair
>
>
>

It does, we use 1.5 % (w/v) streptomycin sulfate and centrifugation
at 20 000 xg to remove DNA. In early steps we sometimes use Benzonase
instead of DNAse to make the solution less viscous.

Kind regards

Torsten
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                          Torsten Boerchers                            /
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