CLED Agar Help Please - (Dec/17/2009 )

I am a student at the University of Portsmouth studying part time for BSc in Applied Science. One of the units taken is clinical microbiology and I have a query relating to CLED agar.

I performed a disk diffusion test on a CLED agar plate inoculated with E.coli. A disk of Trimethoprim was added and incubated to observe growth. The antibiotic disk had some effect upton the growth but had not completely inhibited it - there was no clear zone of inhibition.

I was wondering if there was a certain substance in the CLED agar that contributed to this?

http://photos-e.ak.fbcdn.net/hphotos-ak-sn...8_7099041_n.jpg

hey;

what do you mean with there is no clear zone of inhibition?

I can see a zone of no growth, inhibition on the picture you included.