This Ames test method is a modification of the Ames ISO fluctuation assay. Bacterial strains are pre-exposed to differing concentrations of the mutagenic compounds with a growth media in suspension for 100 minutes. Each dilution is run in triplicate.

The samples are then transferred, mixed with a reversion solution and plated onto a 96-well plate while using a 48-well evaluation format. The samples are incubated for 2-3 days and the number of revertant colonies (individual wells) are counted by colorimetric analysis.

 This method combines the benefits of the ISO method while maintaining the ease-of-use of the Muta-ChromoPlate method. Smaller sample sizes are required and less reagents are used which is similar to the ISO, however, reversion media mixtures amounts and 96-well microplates facilitate pipetting and sample transfer to incubation step which mirrors the Muta-ChromoPlate Ames test procedure. The 48-well format reduces incubation plates required and plate covers reduce loss of highly volatile samples.

This method is a perfect hybrid between facility and efficiency and can be the preferred method depending on sample constituents.

S9 and Activation of Pro-Mutagens (Optional)

 S9 is a crude liver enzyme extract that can, under certain conditions, convert materials without any genotoxic activity to active genotoxic entities. The chemical process involved may be different for different materials. In addition, the lifetime of the activated moieties is extremely variable: some may be extremely short-lived. This is the reason for incubating the S-9 with the bacteria and the tested material at the same time during the assays.

Ames Express Strains – A new alternate for the detection of Pro-Mutagens

EBPI is proud to officially announce the release of our NEW Ames bacterial strains, called the Ames-Express^TM strains.  Ames-Express^TM strains are constructed from normal Ames bacterial strains (TA100, TA98, TA1535, TA97a, TA1538), but have been engineered to also express either human P450 or GST-theta liver enzymes internally, which promotes bioactivation of xenobiotic molecules into DNA reactive species in the absence of an S9 mix.

The Ames Test ISO, Ames Modifed ISO and Muta-ChromoPlate Kit are designed to be run with the traditional Ames Test bacterial strains or EBPI’s new Ames Express bacterial Strains.