Ames test: Ethidium bromide

Dr. James J. Campanella campanellj at
Wed Jul 18 08:42:56 EST 2001

Let's see:

Ames test: You mix auxotrophic mutant E. coli with your putative mutagen,
then you plate the auxotrophic mutant + mutagen on a drop out plate. You
then sit back and look for wild-type revertants that can grow on the
drop-out plate. You compare the frequency of revertants on the treated
plate with a control plate-- the difference between the two is presumably
the level of mutation induced by your presumptive mutagen.

Modified Ames test: You do the same as the above, but you include a liver
extract in your mixture. Many mutagens are activated by enzymes that are
found in the liver, and so they do not become dangerous until they actually
get into the body. These mutagens would show up as being non-mutagenic on a
standard Ames test.

How was that? Did it make any sense?



James Campanella,
Montclair State University
Dept. of Biology
1 Normal Avenue
Montclair, NJ 07043

At 01:03 PM 7/18/2001 +0100, Michael Witty wrote:
>Dear All,
>        what a response!  I feel like the leader of an "angry mob".
>Whenever a subject like this comes up people mention this Ames test and
>Modified Ames test.  I confess that I don't have much of an idea what they
>are - but I suspect that they have a lot to answer for.  Does anyone have
>a sentence that can explain it to me?
>                                     Mike.


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