Qiagen preps in transient transfections are OK

[Ian A. York]

A few days ago there was a question as to whether Qiagen preps worked in 
transient transfections, and it was supported -
In article <3jfav3$n2e at amcnix.amc.uva.nl> seppen at amc.uva.nl writes:
>
>we had a similar problem with obtaining stable transfectants. I now routinely
>do one phenol and two chloroform/iaa exctractions after the maxiprep with
>qiagen. The interfase always contains protein, so qiagen is probably not
>enough to get pure vector.

	I grew up a prep for Qiagen, and used my neighbor's LiCl prep; in 
the past I ran this beside a CsCl prep, and those two were similar.  The 
plasmid contains H-2Dd in pCDM8; I transfected the two preps into COS7 by 
the DEAE-dextran method, and two days later I stained for surface 
expression of H-2Dd and ran the samples through FACS.  

	The efficiency was essentially identical: 25% transfected with the 
Qiagen were positive, 21% of the LiCl transfectants were positive.  These 
are typical numbers in my hands, with this technique - I generally get 
between 20 - 30% expression.  There was no difference in intensity of 
staining, either.  

	I did nothing special to the Qiagen prep - no phenol-chloroform 
or anything.  

	So, at least here, there doesn't seem to be a big problem with 
the Qiagen kit.  It's possible that there is a new formulation that 
hasn't reached us yet, but we go through a fair number of these kits.  

	Ian

-- 
Ian York   (york at mbcrr.harvard.edu)
Dana-Farber Cancer Institute, 44 Binney St., Boston MA 02115
Phone (617)-632-4328     Fax  (617)-632-2627