Desalting of Plasmid DNA after Cesium Preps

Kent S. Boles kboles at
Mon Jul 13 18:23:55 EST 1998

>Rather, I suspect the dialysis membrane adsorbs quite a lot of DNA (I
>definitely *know* for protein samples; if you don´t believe, just dialyse any
>protein you want against any buffer, then take out the sample and wash the
>membrane with buffer. Then, cut the membrane to pieces, boil them in SDS
>sample buffer and apply to a gel. You´ll be shocked...)

I hadn't thought of this possiblility. A good way to test this would be
to drop the sealed tubing in an eletrophoresis aparatus and reverse the
field back and forth a couple of times. It should effectively knock the
DNA off the membrane. Might be interesting to compare side by side.
Just a thought.
Have you ever tried to convince a Qiagen rep that CsCl is better for
removing endotoxin than their reagents?

Kent S. Boles
Department of Molecular Biology and Immunology 
UNT Health Science Center at Fort Worth 
3500 Camp Bowie Blvd 
Fort Worth, TX 76107
kboles at
817-735-5045 voice 
817-735-2118 fax

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