ZERO yield from Qiagen Maxi Prep

Bjšrn Olde bolde at biogen.wblab.lu.se
Thu Jan 23 10:59:40 EST 1997

In Article <32E05F88.596F at sprynet.com>, Louis Geller <bbbbd at sprynet.com> wrote:
>        I have used Qiagen's plasmid maxi-preparation many times to amplify a
>yeast genomic library, always with a good yield and no problems.  The
>library was in E. coli strain DH5-alpha.  
>        Now, we are trying to amplify a single plasmid of this library that
>contains a yeast gene we have cloned by complementation.  The plasmid
>was removed from yeast and transformed into E. coli strain BMH.   
>        After 3 tries, we have been unable to get *any* yield whatsoever!  I
>have checked the buffers for pH.  We made fresh lysis buffer [P2]. 
>During the last run,  samples were removed for the analytical gel and
>will be analyzed.  We are using the same exact kit and reagents that
>have been used successafully before.  We verified that the starting
>colonies have the plasmid of interest.
>        The only thing I can think of is that there may be something different
>about BMH strain that makes such a maxi-pred more difficult.  Still,
>getting no yield seems very strange.
>        If anyone has any ideas or suggestions, please share them.
>        Thanks very much!!
>        Louis Geller,
>        Graduate Student, Cell & Molecular Biology
>        Cal State Long Beach
>        lgeller at csulb.edu    or     bbbbd at sprynet.com
We had the same problem using the midi-columns until a Qiagen representative
told us that we were overloading the columns. Overloading Qiagen columns
apparently gives this kind of effect.


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