TELT Minipreps - Avoiding C'somal DNA ?

Tim Chipman tchipman at
Tue May 27 22:09:41 EST 1997


Within the past few weeks, a "Speed Prep" MiniPrep technique was posted,
based on using a LiCl / Trition-X-100 ("TELT") buffer in combination with
Phenol:Chloroform to isolate plasmid DNA.  I've tried this a bit with a
number of "test" preps in parallel with alkaline lysis preps, and while I
do find the speed increases significant and conveninent, I find a number
of major drawbacks, namely

-Chromasomal DNA is isolated as well
-Plasmid yields are significantly lower for the TELT prep

Despite suggesions by some lab members, plasmid size didn't appear to
decrease TELT yields - at least within the scope of sizes I tried (two
plasmids with 4.5kb inserts, another with an 8.5kb insert). This was one
of the primary things I wanted to diagnose with my parallell TELT/NaOH
lysis preps, but also was when I clearly observed the piles of
chromasomal DNA.

Thus, I am curious:  Have others already done various troubleshootings and
observed how to get a TELT prep to yield essientally only plasmid DNA? How
about yield?  Are there any comments / pointers ? (I did find the original
1990 ref in NAR on the TELT prep, and essentially the same procedure in
"the red book" but haven't found anything since, which suprised me.) 

Please email any comments to me at: Tchipman at


Tim Chipman

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