EcoR1 trouble with maxi-prep DNA

[Brian C. Kang]

In article
<Pine.SOL.3.95.961008143608.13648A-100000 at ascc.artsci.wustl.edu>, Alex
Brands <abbrands at artsci.wustl.edu> wrote:

> I have a low copy number plasmid that I need to cut with EcoR1, but the
> digestions so far have been incomplete.  Since it is low copy,and a
> regular miniprep doesn't give enough DNA, I used a maxi prep kit from


Hi Alex;

The problem of difficult digestion has been encountered by many people who
were using alkaline maxiprep method (Promega maxiprep is also one of
them).

The carried over SDS might be the one of culprit.

One day, my big and pounding headache was cleared by changing the alkaline
method to boiling method. You can scale up the boiling miniprep method to
maxiprep method. I was using the 20 min ultracentrifubation for
precipitating the protein-genomic DNA aggregates.
 hope it helps