Qiagen: This is ridiculous

brett brett at BORCIM.WUSTL.EDU
Sun Aug 25 10:13:43 EST 1996

>I've been using Qiagen DNA preps for years.  The quality is great; as 
>everyone who's used them knows, though, the yield is at best 
>inconsistent.  At random intervals, and for no apparent reason, there 
>will be absolutely no DNA produced.  I've been willing to deal with that 
>when I was getting 5 out of 6, or whatever, with good yields; with 
>important DNA, I'd always run duplicates to be reasonably sure of getting 
>In the last two days, I've run 10 Qiagen DNA preps - 8 midi-preps, two
>maxipreps - and got one (1) with detectable DNA.  Meanwhile two identical
>cultures, run on a different company's resin, gave 160 ug and 175 ug of
>DNA from 200 ml bugs (low copy-number plasmid). 
>One out of ten is not acceptable.  Over the years I've gone around and 
>around with Qiagen reps, I've tried dozens of variations on the protocol, 
>I've tried everything they suggest, I follow the directions exactly, and 
>in spite of it I just spent two days pouring DNA down the sink.
>The hell with it.  Until I hear from users that the Qiagen preps are
>reliable, I'm not going to use them any more. 
>Blowing off steam, 

Switch to CsCl...it's really not as labor intensive as everyone thinks. Given
your futile preps, it will no doubt save you time and money. And you will
never have to worry about the quality of your DNA...CsCl banding is the
gold standard
(ever notice what Qiagen compares their preps to?)

Brett Lindenbach
Program in Immunology                              
Washington University - St Louis                  
brett at borcim.wustl.edu                             

"I own my own pet virus. I get to pet and name her." - Cobain

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