LB or not LB...B, that is the question

Dirk Bornemeier bornemd at
Thu Nov 18 09:27:41 EST 1993

In article <1993Nov17.135848.1 at>,
dallas at wrote:

> > stuff deleted
> > 
> > Any further quoted recipies?
> There is:
> Luria-Bertani Broth  L-B Broth  (or is it just LB and somebody screwed up)
> 10 g J. Miller (no relation ;-) )
> Luria Broth 0.5 g/L
> and...  Lennox Broth J.Virol. 1:190-206 (1955)!!!  Is this also L Broth??
> > 
>  LB or not to LB...B, that is the question.
> Seriously, in my graduate days I was told that E. coli 'like' more salt and
> therefore a 20x amount (from 0.5g/L, Luria broth) to 10g/L (Luria-Bertani
> broth) was in order.  From my scribbled notes in my Miller book(1972), I have
> "10x NaCl, L broth...Lennox (1955)"  By the way, Luria and Lennox, but not L-B
> calls for pH'ing with NaOH.

Current Protocols in Molecular Biology (the "red book", Ausubel, et al)
says the following:

LB medium, per liter
10 g tryptone
5 g yeast extract
5 g NaCl
1 ml 1 N NaOH
The original recipe for LB medium (sometimes referred to as Luria or Lenox
broth), does not contain NaOH.  There are many different recipes for LB
that differ only in the amount of NaOH added.  We use this formula for our
own work.  Even though the pH is adjusted to near 7 with NaOH, the medium
is not very highly buffered, and the pH of a culture growing in it drops as
it nears saturation.

[end quote]

This recipe is confirmed in the 1993-1994 GIBCO/BRL/Life Technologies
catalog (page 10-3) which also provides references for LB and variations by
Lennox, Enquist and Sternberg, and Miller.

Hope this helps.

Dirk Bornemeier
Ann Arbor, MI

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