smrodems at students.wisc.edu
Tue Feb 8 22:49:07 EST 1994
In article <leach-070294235254 at med-pharm16.bu.edu>, leach at mbcrr.harvard.edu
(Martin Leach) wrote:
> In article <2j5rhh$bs8 at mserv1.dl.ac.uk>, dmorgan at crc.ac.uk (Mr. D.D.
> Morgan) wrote:
> > We have recently started to use Promega's "new" Wizard Mini and
> > MAxiprep kits and have found the plasmid DNA degraded. Does
> > anyone have any tips or hints to improve the quality of the
> > DNA. (We used the Magic MINipreps without any of these problems)
> Don't buy Wizard preps.
I use Wizard minipreps quite often for sequencing miniprep DNA. They work
great for sequencing; they're fast so I can easily do 16 minipreps,
sequence them, and run the gel all in a day. BUT...I had problems with
Wizard Midiprep DNA. I prepared a stock of plasmid from a 40 ml culture
using Wizard Midipreps and when I tried to digest the DNA I got a
substantial degradation of the DNA. This happened with two different
restriction enzymes. It cost me about a months worth of work because I
thought my problem was the enzyme until I cut the DNA with a different
enzyme and it did the same thing. Also, I get much better transfection
efficiencies (transfecting into insect cells using CaPO4) with CsCl pure
DNA than with Wizard preps. Thus, I've dropped using Wizard preps except
if I need to sequence minipreps. Strange it can give you DNA good enough
to sequence but not good enough to do a simple digest.
I wonder if anyone from Promega is listening?
Steve "Some day I will get the hell out of Wisconsin" Rodems
"You know, the other day I ... oh, wait, that wasn't me"
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