Qiaex II Gel Extraction Kit

Gerd gerdn at ibg.uit.no
Tue Sep 1 06:14:36 EST 1998

Beat wrote:
> Dear all,
> I am using Qiaex II Gel Extraction Kit to extract a very well amplified 500bp
> PCR product from agarose gels. Using special agarose (SEAKEM GTG), did not
> overdry the pellet, and was using TE buffer pH 8.0 (pH of MiliQ is too low) to
> redissolve the DNA...  changed all variables in the system...
> However, final DNA yield was always very low  (aprox 7ng/ul), miles away from
> the 60%  efficiency given by Qiagen.
> Does somebody have a solution to this problem?
> I appreciate your help!
Have you tried extracting twice (or more) with hot buffer, 65 C. If you
are worried about the volume, use less buffer each round. Or do
presipitate after. Keep the tubes at 65 C some minutes, before spinning.
If that do not work, your DNA must have been washed away. In that case,
increase the chances of binding to the matrix, by adding more ethanol if
thats what is used (I do not have the protocol, haven't even used the
kit, only a lot of others - principles are generally about the same)
 And, if you are going to buy a new kit, try the Qiaquick. It has worked
surprisingly well in our lab.

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