Cm-R or Gm-R cassette?

Brad Nicholson brad at
Fri Aug 18 15:52:59 EST 1995

In article <t.barnett-180895155956 at>, 
t.barnett at () wrote:

> Hi,
 >I am after a chloramphenicol-R or gentamicin-R cassette 

Hi Tim,
There are a couple of things that you can do. If you are in a hurry, you 
can get a nice cat gene from pACYC184.  The gene is contained on a 1325 bp 
fragment from a Hae II digest, it's the largest band, you can then blunt 
with knenow and clone in to a blunted site of your choice.  It sounds 
complicated, but it's not that bad because all your non-recombinants die.  
The down side is that there are no additional transcriptional terminators 
after the stop and you could possibly have some sort of promoter activity. 
I don't know about expression in Aeromonas spp., but the original cat gene 
in pACYC184 came from Tn9.

If you have some time, there is a recent paper out by Alexeyev, Shokolenko 
and Croughan. 1995. Improved antibiotic-resistance gene cassettes adn omega
elements for Esscherichia coli vector construction and in vitro 
deletion/insertion mutagenesis. Gene, 160:63-67.  They describe some nice 
omega elements with cam and gent resistance genes.  These constructs come 
is several flavors, with a plethora of available cloning sites.  
Correspondence is directed to: 
Dr. T. P. Croughan
Rice Research Station
P.O. Box 1429
Crowley, LA 70527-1429
Tel.(1-313) 788-7593
Fax.(1-318) 788-7553
e-mail:agexp86 at

(I first read about these vectors on this newsgroup, I can't remember who 
posted it, but they should get an attaboy also.)

Good luck,

Brad Nicholson              |"If it worked the first time, it wouldn't be 
Department of Pathology     |	research."...Brad Nicholson
University of Utah          |	Live from behind the Zion Curtian.
Salt Lake City, UT 84132    | 
brad at    |
or: (801)-581-4365          | My opinions are solely my own.

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