Neomycin/Kanamycin Resistance

C. J. Fields cfields at
Mon Feb 3 00:56:47 EST 1997

I have had problems with a cosmid (pYUB18, an E. coli-Mycobacterium
shuttle vector).  It has a neo resistance cassette on it; the paper
describing it says to plate it on kanamycin, however.  When I do this to
my tranformants, I get no growth; however, if I use neomycin sulfate, I
get great results (I electroporated the cosmid in and checked the
transformants on a gel via rapid plasmid prep; I am about to CsCl prep
them).  Furthemore, the lab where I got it uses kanamycin, with
supposedly great results!

Has anybody had problems similar to what I experienced, and is there any
particular reason why the preference is with kanamycin instead of
neomycin?  They're very different structurally.  If anyone has a great
explanation, I'd like to hear it.
C. J. Fields
Graduate Student, Dept. of Biological Sciences
The University of North Texas
Denton, TX 

email : cfields at

I need to change my signature!!!! It's getting old.

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