removing nucleic acids from extracts

Dr. Jeffrey F.D. Dean jdeanx1 at
Tue Jan 30 08:17:19 EST 1996

trey simmons wrote:
> Hello all; I'm hoping someone can help with what I think should be a
> straightforward question. I'm purifying a protein in E. coli using


> Any suggestions would be appreciated.
> Trey Simmons
> Gladstone Institute for Cardiovascular Disease
> San Francisco, Ca.

One of the first lessons I was taught as a new graduate student was the 
effectiveness of protamine sulfate for precipitating nucleic acids from 
bacterial lysates.  I have infrequently come across proteins that 
co-precipitate, but I still use this method with bacterial, plant, 
and fungal extracts.  Try slow addition of 1:20 vol of a 2% solution of 
protamine sulfate in extraction buffer.  Stir at 4°C and a precipitate 
should form straight away.

Good luck.

More information about the Proteins mailing list