Purify large fragment from Agarose gel >10 Kb

[brett]

>Hi, Netters,
>
>Does anybody out there any give me some references or any methods, kits, 
>which work well for purification large fragment from agarose gel?(>10 kB)
>
>We met unstable results by using Geneclean or Qiagen kit.
>
>Thanks!
>
>
>Huang

Just yesterday I compared three methods for isolating ~200ng of a linear
12kbp fragment from LMT.  I got quantitative recovery by phenol extracting
2x (use no CHCl3) and EtOH pptn of the melted gel (glycogen as carrier).
I tried Boehringer's Agarase followed by pptn, also quantitative.  And I
also extracted the fragment using a homemade "Wizard" miniprep kit (ala
this newsgroup), which gave me ~40% recovery but was the fastest method.


Brett Lindenbach
                             
Washington University - St Louis                  
brett at borcim.wustl.edu