Stubborn DNA during resuspension

Richard Daines rdaines at
Sun Jan 14 09:33:51 EST 1996

Graham Dellaire <popa0206 at PO-Box.McGill.CA> wrote:
>>   Richard Daines <rdaines at> writes:
>>  I have run into this problem myself. I get excellent DNA yeilds (seen when 
>>  I ppt, nice long spoolable DNA) but if I centrifuge, the pellet us almost 
>>  totally insoluble.  I've always blamed co-ppt of carbohydrate as the 
>>  problem.  I seem to be able to get enough back into solution to be useful 
>>  and keep the rest as a pellet.  Sorry but I don't have a cure for this 
>>  problem.
>I have the same problem with some preps
>If it is from a bacterial prep sometimes the insoluble pellet is bacterial genomic DNA that is complexed with lipids and 
>carbohydrates.   The way around this people is to use an expensive column system like "quiagen" or good old CsCL
>gradient purification

I do use Qiagen columns along with a proteinase K treatment.  The 
problem does appear to be species related (at least in Streptomyces) and I 
had similar experience with it the plant genomic preps.  One can usually 
get enough DNA to work with however.

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