ampicillin analog?

eric anderson e-anderson at
Fri Mar 14 09:58:58 EST 1997

In article <5g92nd$pho at>, bernard at (Bernard
Murray) wrote:

> In article <199703130138.UAB171874 at>,
bob_chapman at 
> says...
> >
> >We're using an ampicillin based expression system but may be having 
> >trouble with scale-up due to ampicillin depletion. My boss remembers 
> >seeing an lactamase resistant analog of ampicillin compatable with 
> >our AmpR vector. Can anyone provide a refference to such an 
> >antibiotic?
> I don't actually have a reference but...
>         You are probably refering to carbenicillin which is chemically
> more stable than ampicillin (?less protein reactive).  It is, of course,
> *not* resistant to beta-lactamase (as otherwise it would kill ampR
> bacteria) but lasts longer in agar plates and in liquid cultures.
> The downside is that it is considerably more expensive than ampicillin.
>         Another alternative is a mixture of ampicillin + methicillin.
>                 Bernard
> Bernard Murray, Ph.D.
> bernard at (National Cancer Institute, NIH, Bethesda MD, USA)

the downside of Amp+Meth is that Methicillin is no longer available from
Sigma, Fluka or Calbiochem (all places where we have gotten it in the
past).  if anyone still knows of a source of Methicillin i'd love to hear
about it.  we've got 25g still but that won't last forever.


Eric C. Anderson
Memorial Sloan-Kettering Cancer Center
Sloan-Kettering Institute
1275 York Ave. Box 470
New York, NY  10021
(212) 639-2977
e-anderson at

More information about the Methods mailing list