plamid prep

theodorn at theodorn at
Thu Aug 6 12:10:05 EST 1998

In article <35C9C3D4.6FA73A57 at>,
  fof1 at wrote:
> 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

With ordinary superbroth, I usually max out a Qiagen-500 column (so therefore,
500-600 ug) with Bluescript from a 50 ml culture (in DH5alpha), which would be
about 10 mg per liter of culture.  When I used to do CsCl preps, I could get
even more.  So therefore superbroth would seem to be a pretty economical
alternative since phosphate isn't as expensive as MOPS.

Nick Theodorakis

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