insoluble DNA pellet after Qiagen Tip20
Tue Jun 21 10:13:48 EST 1994
In article <eggermon-200694162025 at 22.214.171.124>,
eggermon at popserv.kuleuven.ac.be (Jan Eggermont) wrote:
> Last week I tried Qiagen Tip 20 columns to prepare some DNA. It all went
> fine until the very last step. After the isopropanol precipitation and the
> ethanol 70% wash there was a small pellet visible at the bottom of the
> tube. However, I could not resuspend this pellet in TE. I tried all sorts
> of tricks such as vortexing vigourously, increasing the volume of TE to 100
> microliters, heating to 50 0C, but to no avail. I then 'reprecipated' the
> pellet, washed it extensively with EthOH 70%, but the final pellet was as
> resistant to resuspension as the first one (despair....).
> 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.
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.
sdcoon at umich.edu
University of Michigan Medical Center
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