insoluble DNA pellet after Qiagen Tip20

Andrew Healey andrew at
Tue Jun 21 23:51:51 EST 1994

: In article <eggermon-200694162025 at>,
: eggermon at (Jan Eggermont) wrote re qiagen tip-20's

: > 
: > Has anyone experienced similar problems with the Tip 20? Any help,
: > suggestions and tips are greatly appreciated...
: > 
: > PS: I have also used the Tip 100 colums which worked fine. No problems in
: > resuspending the final pellet.

and sdcoon at (Steve Coon) replied:

: Sounds to me like you overloaded the column with too much bacteria and/or
: didn't wash enough of the protein (it is your insoluble material) away.
: They warn you about this in the directions. Just use less. 

Don't think so. I think you'll find it even after copious washing in some
instances. I believe (though can't prove) that it is loose resin. I've
observed the same phenomenon for some time. If you spin the column eluate
down hard immediately before precipitating the stuff pellets out. Then
transfer the supt. to a fresh tube and precipitate that with isopropanol.
Works for me.

email: andrew at  
The Bancroft Centre, Queensland Institute of Medical Research
300 Herston Road, Brisbane, AUSTRALIA 4029
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