E. Coli Transformation

Zophonias O. Jonsson zjons at vetbio.unizh.ch
Thu Oct 19 03:52:20 EST 1995


In article <rocco-1810950828400001 at haarerlab.zo.utexas.edu>,
rocco at mail.utexas.edu (Stephen J. Palmieri) wrote:

> ... if I transform a ligation reaction I get these colonies containing no 
> plasmid DNA and have a really bizzare odor and look in liquid culture

  This smells familiarly to me.  When I was working at the genetics lab at
the University of Iceland we had similar problems for a few weeks.  Bugs
that smelled something like a cheap detergent, grew extremely fast, were
resistant to every antibiotic we tried and were bright green in liquid
culture.  They showed up whenever someone was doing an important
transformation.  We sent a sample to the Microbiology lab and they
diagnosed is as Pseudomonas fluorescens (sp?).  We finally traced the
source back to a single waterbath and after thorough cleaning and addition
of generous amounts of NaN3 the problem went away.
  Could it be that the water bath where you are doing your ligations is
contaminated?

Just a thought

Zophonias

_____________________________________________________________________
Zophonias O. Jonsson
Institut fur Veterinarbiochemie               Tel: (41-1)-257-54-75
Universitat Zurich-Irchel                     Fax: (41-1)-362-05-01
Winterthurerstrasse 190
CH-8057 Zurich
Switzerland
_____________________________________________________________________



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