Large scale plasmid preps

nishir at nishir at
Fri Apr 30 15:03:35 EST 1993

In article <1993Apr27.160558.29038 at> jnppo at (James N
Petitte) writes:
>Does anyone have experience with Qiagen's large scale plasmid prep columns?
>What are some of the realistic yields that can be expected?  Is it useful for
>transfections?  How clean is it?  Are there any other methods beside CsCl
>that are equivalent?
>Jim Petitte
>JIM_P at
I have not compared various DNA isolation methods but got handed a protocol and
some Qiagen tips and have now done a number of preps.  The procedure is nice
because it is so fast. The yield we got of PGEM plasmid from a l liter 24 hr
culture processed over 4 Qiagen tips 500 was 1.8mg (being naive the first time
around, I followed the directions in the manual for the column capacity; I have
since learned that you can take plasmid from a 500-750 ml culture onto a single
tip 500).  We now do "midi" preps of 100 mls of culture onto a tip 100.  The
yield seems to depend upon the plasmid + insert.  The same PGEM plasmid that
gave us such a large yield only gave us a tenth as much with a different
insert.  The DNA looks very clean on a gel, and it cuts well.  The major
drawback of using these tips is that they are very expensive.

Rae Nishi
Cell Biology & Anatomy
Oregon Health Sciences University
Portland Oregon  

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