Get rid of DNA?

Dr. Hiranya S. Roychowdhury hroychow at
Tue Feb 18 11:01:24 EST 2003

Naturally, the protien-bound strecthes of DNA will be resistant to DNase 
treatment! So, the logical step would be to dissociate the bound DNA by varying 
the salt conc. followed by DNase treatment.  The exact procedure and salt will 
have to be empirically determined.

Quoting EK <khatipovNO-SPAM at>:

> Following a trend of last week's "get rid of" questions, let me ask you
> mine.
> If one purifies a DNA-binding protein complex, what would be the most
> appropriate way to get rid of DNA during the purification, so that the
> protein prep could be later used for DNA binding assays? It does not seem
> to
> me that DNAse treatment did a lot in my case. I still can see a cloud of
> 100-200bp oligos in the protein prep. Someone recommended Heparin sepharose
> chromatography step, but others argued that heparin itself is difficult to
> get rid of (what an irony! :-)). I believe the presence of bound DNA is the
> reason why I cannot see any shifts on my EMSA's.
> I would appreciate any input here.
> Thanks!
> - Emir

Hiranya S. Roychowdhury, Ph.D.
Coll. Asst. Professor,
Molecular Biology,
Dept. of Chemistry & Biochemistry
Rm# 336, Chemistry Bldg.; MSC 3MLS
New Mexico State University
Las Cruces, NM 88003

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