Phage library contamination

Shiao Y. Wang sywang at
Thu Apr 28 22:42:41 EST 1994

Matthias Zeiner (mzei at wrote:
: On Wed, 27 Apr 1994 13:04:54 +0000, Duncan Clark wrote:

: >In article:  <2pj0ov$4uj at>
: >  "Matthias Zeiner" <mzei at> writes:
: >
: >> 2) With their gt11 libraries Clontech supply Y1090 strains that are    
: >>    resistant to T7. Probably they harbor a F'plasmid providing       
: >>    resistance.
: >
: >
: >An F' that makes cells resistant to T7? How does that work?
: >
: > 
: To my knowledge T7 phages don't grow on E.coli strains harboring an F 
: plasmid (Hfr, F', F+). Host cells are infected but phages cannot replicate 
: ("abortive infection"). I don't know if the mechanism which leads to that 
: kind of restriction really is understood. Details are in  Birge, E.A. 
: (1988) Bacterial and Bacteriophage Genetics: An Introduction. Second 
: Edition. Springer-Verlag, New York.

: Matthias Zeiner
: Inst. Biol. Chem.
: INF 501
: D-69120 Heidelberg
: mzei at

I'd like to add that I think ClonTech needs to be a little more
responsible for their products. I purchased their Uni-Amp Universal DNA
Amplification System a couple of years ago and I couldn't get it to work.
Even their controls didn't work. I finally got to talk to the scientist
that apparently was involved in the original development of the product and
couldn't get anywhere. I was pretty mad at the end when he told me to stop
bothering him because he was a "scientist" when I called back to let him
know that what he suggested didn't work. 

Bottom line: be aware that not all products will work as claimed. Demand a
refund when a product doesn't work. (ClonTech shipped me an "improved" kit
called the PLUS kit that wouldn't work either. I had spent two months
trying to trace the problem and basically just gave up at the end).

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