plamid prep

Frank O. Fackelmayer fof1 at chclu.chemie.uni-konstanz.de
Thu Aug 6 09:55:09 EST 1998


Hi Jim,
There´s always the same problem with BioTechniques. There is the full journal,
and a "diet-version", the so-called Euro-Edition. The reference is ok, but I
guess you looked it up in the Euro-Edition of the journal.

the medium described in the paper, called H15, looks promising but also quite
expensive. The paper describes a well controlled study on the performance of
this new medium. It appears to produce up to 30fold the number of bacteria in
the same volume, and an equal increase in DNA yield. The key seems to be the
very high buffering capacity of the medium, effectively protecting the bugs
from medium acidification. The recipe is: 

1% RNA (Sigma R-6625)
10ug/ml RNase A (Sigma)
5% Yeast extract (Difco)
1% Casamino acids (Difco)
2% Glucose
150mM MOPS
272mM Tris
titrated to pH 7.6 with HCl.

The most expensive ingredient is certainly MOPS. Even though the authors claim
the medium is "very economical", the price per mg of DNA you get is not very
different from, say, using LB. The main advantage seems to be that you can get
along with a lower culture volume (which is easier to handle, of course)

I haven´t tried it, so I cannot comment on the performance.

Hope this helps,
Frank



Jim Hill wrote:
> 
> > Hi!
> >
> > Have a look at BioTechniques 24: 438 - 444 (March1998). They have this
> > incredible medium which they claim to yield as much as 48 ug/ml of a
> > high
> > copy plasmid such as pBluescript. So a little more than a litre would
> > be sufficient in this case?!;-)
> >
> > Ricky
> 
> Hi,
> 
> I'm rather interested in this article myself, however my issue of
> BioTechniques from March 1998 has neither that issue number nor those
> page numbers. Could you check your reference please?
> 
> Jim



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