Jump to content

  • Log in with Facebook Log in with Twitter Log in with Windows Live Log In with Google      Sign In   
  • Create Account

Submit your paper to J Biol Methods today!
- - - - -

Chloramphenicol resistance gene and Chemicomps E. coli (TOP10, Mach1)

  • Please log in to reply
2 replies to this topic

#1 ruiN



  • Active Members
  • Pip
  • 6 posts

Posted 18 June 2009 - 12:58 PM

I use the Cm resistance gene from L. lactis (gr+) as a selectable marker for my cloning, and it seems to make TOP-10 and Mach1 cells awfully sick. They're in fact resistant (gene is expressed) but they're just not growing well. Colonies take forever to grow and are tiny. Is it possible that the nature of the gene is not fully compatible with E. coli? Has anybody seen such a thing?


#2 Carlton H

Carlton H


  • Active Members
  • PipPipPipPipPip
  • 95 posts

Posted 19 June 2009 - 09:19 AM


I think it's more likely that your Cm resistance gene is underexpressed and isn't conferring full resistance. Did you quantify your expression levels at all?

Reliable laboratory instruments for the life sciences, designed to enable you to work more effectively and increase productivity. Check us out!

If my answers help you, please take a moment to check out our site and see if any of our products would help you as well! Thanks!

#3 phage434



  • Global Moderators
  • PipPipPipPipPipPipPipPipPipPip
  • 2,747 posts

Posted 19 June 2009 - 03:03 PM

If this is the cassette out of pC194, then it expresses poorly in E. coli, and is also inducible. The 5' UTR contains a stem loop which inhibits translation.

Horinouchi S, Weisblum B. Nucleotide sequence and functional map of pC194, a plasmid that specifies inducible chloramphenicol resistance. J Bacteriol. 1982 May;150(2):815-25. PMID: 6950931

Removal of the stem-loop allows constitutive resistance, but still significantly lower resistance than the normal E. coli cat gene expression. See http://partsregistry...Part:BBa_J70304 and the design note page for the part.

Home - About - Terms of Service - Privacy - Contact Us

©1999-2013 Protocol Online, All rights reserved.