NH4Ac-Miniprep becomes bad - why?

Michelle Gleeson michelle at MOLECULE.BIO.UTS.EDU.AU
Thu Aug 29 16:54:56 EST 1996

On Thu, 29 Aug 1996, * wrote:

> Hi there
> Recently I switched from the Qiagen miniprep protocol to an
> alternative method using an RNase containing resuspension buffer as
> well, lysing with NaOH/SDS but precipitating genomic DNA and proteins
> with 6M Ammoniumacetate. Precipitating the supernatant with Isoprop
> gave a yield of plasmid (sequencable) as high as 25ug from a 1.5mL
> culture.
> So I made a kit containing all the components that I need for the
> prep. After a while (month) though my yields decreased rapidly until
> the method didn't work at all anymore. So I made fresh solutions and
> *bingo* it woked again. Now, after another month, the same problem
> reoccures.
> It would be much easier if I knew *what* solution is becoming bad and
> I would be interested in *why* it happens and how to *avoid* it.
> Anybody with similar problems???
> Thanks
> Mike

Can you please post details of this protocol, references etc?
As for which solution is going bad, are you refrigerating the solution
containing the RNAse?


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