neomycin-G418 confusion

Michael Benedik benedik at
Fri Nov 6 17:03:34 EST 1998

In article <717ico$n04$1 at>
"Wolfgang Schechinger" <Wolfgang.Schechinger at>

> Hello Martin, 
> The story about Neomycin and G418 is this: 
> 1. The NeoR gene is coding for neomycin phosphotransferase
> 2. Neomycin binds to ribosomes in certain Prokaryotes
> 3. G418 binds ... Eukaryotes
> 4. Neomycin phostransferase phosphorylates both G418 and Neomycin and 
> renders them inactive.
> 5. G418 is only effectice in Eukaryotes
> 6. Neomycin ... Prokaryotes. 
> This all is written down nowhere. It seems to be 
> common sense <GG>.  
> 7. Maybe those guys who are writing the catalogues are reading this 
> message here and will include these hints in every catalogue.
> Wolfgang 
> -----
> usual disclaimers apply * This message is RNAse free - please don't touch!
> -----                              
> Wolfgang Schechinger         
> University of Tuebingen, Germany
> email: wgschech at * wwWait:
> -------

Almost. G418 is effective against both Prokaryotes and Eukaryotes. It
was originally found (I think at Schering-Plough) as a standard
antibacterial anti-biotic. It was an exciting and wonderful new drug...
until they got to animal studies and all their mice died. Then they
found it works on both. 

kanamycin and neomycin only work well in proks, and are interchangable
for E.coli work (kanamycin is much cheaper). Other bacteria do better
with one drug or the other. G418 is just too expensive to use for
bacteria but it would work fine.

Michael Benedik                                         
Department of Biology and Biochemistry                      
University of Houston                   Tel: 713-743-8377
3201 Cullen Boulevard, HSC 402          Fax: 713-743-8351
Houston, TX 77204-5513              email: benedik at

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