QIAquick gel extraction kit - high salt problem - QIAquick gel extraction kit - high salt problem (Jun/25/2002 )

G'day!
I would like to know if other people have experienced problems cloning DNA which has been processed through the QIAquick gel extraction (spin column) kit.

The kits had worked just fine in my previous experience, and their PCR spin columns continue to perform well...but now the last 4 batches of gel ex kits I have tested all render vectors/inserts useless for ligation.

Lot numbers:
BY1036/104/210
10912775
GHQ029/1063332.2/54
10913361

Having tried EVERYTHING (good quality linear DNA in water treated as if a gel slice, Low Melting Point Agarose, QG wash x2, elution in EB versus H2O, PE from PCR purification kit, etc etc)...I have found that something in the kit vastly increases the salt concentration of the eluted DNA, as determined by Absorbance @230nm.

If you have had a similar experience, please contact me - Qiagen either don't know or don't care about the defect (they sent me two defective replacement kits).

Greg Parsonage

Did you remember to add the ethanol to the second buffer?
Or maybe you can try wash away the salt by ethanol precipitation.