Ligation problems on agarose-isolated fragments

Peter Horn hornpete at
Mon Feb 19 13:28:14 EST 1996


I haven't been following methods-reagents lately.  Could someone fill me in
on the details of this thread...  We have been using Qiaex to isolate
agarose purified DNA for subcloning for 3 or 4 years.  Everytime we have
reordered, it seems like they have changed the kit, and that the kit has
different quirks.  Anyway, ever since the switch to Qiaex II we can't
ligate anything.  Can't even reclose a blunted vector!  I think it might be
EtOH carried over from the wash steps.  I'm EtOH ppt and religating.  Has
anyone else had this problem with Qiaex II prepared DNA?  Thanx a heap for
your help.

In article <DMu8Gq.4qB at>, "Mark R. Miglarese"
<miglaresemr at> wrote:

> Try FMC SeaKem GTG agarose.  It's high grade and lacks alot of stuff 
> that gets carried over into your ligations.
> Mark R. Miglarese, Ph.D.
> Cancer Research
> Pfizer Central Research
> Box 372                        
> Eastern Point Road              
> Groton, CT 06340
> Phone: (860) 441-8478
> FAX:   (860) 441-1290
> Email: miglaresemr at

hornpete at
Dept. of Biochemistry
Michigan State University

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