removal of PEG from DNA disolved in TE?

Dr. Duncan Clark duncan at
Wed Feb 19 11:52:50 EST 1997

In article <vnp-1902971354020001 at>, Venkat
Pisupati <vnp at> writes
>Can anyone tell me how to remove PEG from my DNA solutions?
>I have lambda preps that I wish to cut and then spin in a microcon 100 to
>separate the oligo linkers, but nothing goes through the filter because of
>all PEG, I think  (the stock DNA solution is milky white and there is only
>5-10 ugs of DNA in the restriction reactions that I am trying to spin.).
>Chloroform extraction does not seem to do anything.

Ethanol ppt and wash the DNA pellet with 70% ethanol. I have my doubts
that your milky solution is PEG because PEG in solution up to at least
40% is clear. It would only be cloudy if it is ppting your DNA in that
stock solution. I PEG ppt litres of phage at a time to prepare 100's of
mgs of lambda and have never had a problem with PEG in the final DNA

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

Duncan Clark
DNAmp Ltd.
TEl/FAX 01252376288

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