removing nucleic acids from coli extracts?

Dr. Duncan Clark duncan at
Tue Jan 30 06:08:53 EST 1996

In article <310CF591.588A at>, trey simmons <trey_simmon
s.gicd at> writes
>I'm sure there's a really obvious way to 
>remove these nucleic acids, but it's escaping me at the moment. Any 
>suggestions would be appreciated.

A non-chromatographic method is using Streptomycin sulphate (1% final
from fresh 20% stock in H20) or Polyymin P (polyethyleneimine - 1% final
from 20% stock in H20 pH'd to 7 - lot of conc. HCl!). You may find that
either will also ppt your protein so try different %'s and inclusion of
say 0.2M NaCl in your buffer will also help. Usual way to remove the
PolP is via AmmSO4 but chromatography is also effective. If you want a
chromatographic method then any DEAE or QAE column at pH 7.5-8.0 will
bind RNA and DNA in 0.3-0.5M NaCl. A CM or S column will act as a
negative purification if your protein binds to that.

The problem with being on the cutting edge is that you occasionally get 
sliced from time to time....

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