Isolating High MW DNA from Gel- Best Way??

Tony Hodge tph at
Thu Mar 17 03:53:04 EST 1994

In article <2lq4ea$kh0 at> Andrew Simmonds,
asimmond at writes:
>One problem with Geneclean is that the glass fines tend to break up
>fragments of DNA due to the DNA binding to multiple glass beads and 
>basically being pulled apart during re-suspention of the glass/DNA 
>mixture...(I seem to remember a disclaimer to that fact on the
>documentation).  One improvement I have seen on this technique is
to use 
>a cartridge/insert, (orginally developed by Millipore?) that is
>a glass filter arranged in such a way that you can run the DNA
>through it and have it adhere without the problems associated with
>glass powder.  It is marketed as a kit in Canada under such names
>Glassmax(Gibco/BRL) etc.
>(I don't work for either firm, just use their stuff....)  

Subject: Re: DNA from Gel - GeneClean
From: Mark Jason Logan, mjlogan at
Date: 15 Mar 1994 23:40:12 GMT
In article <2m5h0s$mku at> Mark Jason Logan,
mjlogan at writes:
>I think you may run into some problems trying to remove large
pieces of
>DNA from agarose with GENEClean.  You will end up shearing much of
>DNA in the process.  I think there is some mention of this in the
>GeneClean manual.  Shearing occurs when the DNA is large enough to
>more than one surface (bead, whatever).  For moderate sized pieces
of DNA
>this is the way to go.

This is true but only claimed to be a problem for >15kb (see
original post).  I have used GeneClean to clean up Lambda DNA before
now out of desperation (before other products were available) and
got decent clonable DNA.  Basically you do the NEW washes very!
carefully not worrying about re-suspending all the pellet every
time, doing a gently mix when eluting and elute twice.


Tony P Hodge
Structural Studies Division
Medical Research Council Laboratory of Molecular Biology
Hills Road
CB2  2QH

Phone (0223)  402260

Fax     (0223)  213556

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