helper plasmid

[Brad Nicholson]

In article <71519f$5hi$1 at mserv2.dl.ac.uk>, "John Grant"
<jgrant at srv0.bio.ed.ac.uk> wrote:

> Hi - I'm trying to get hold of a helper plasmid that has a selectable 
> marker other than Kan or Tet.....can anybody help me out?
> Thanks very much
> John Grant
> 

John,

I'm assuming (dangerous) that you are looking for a conjugation delivery
helper plasmid.  Check out de Lorenzo, et al. 1990. J. Bact.
172:6568-6572.  Look at the following strain.   S17-1 lambda-pir  Tp-r,
Sm-r, thi, pro, hsdR- M+, RP4:2-Tc:Mu:Km Tn7, lambda pir phage lysogen.  

In my hands it is neither Kan or Tet resistant and is able to mobilize an
R6K ori plasmid.  

Good luck, 

Brad