The micro ‐Ames test: A direct comparison of the performance and sensitivities of the standard and 24‐well plate versions of the bacterial mutation test

We describe methods and results used in direct comparisons of the sensitivity of micro and standard systems using the same cultures, formulations, etc. Initial testing utilized the plate incorporation method and, later, the pre‐incubation method. In a subsequent phase of testing, a four‐way direct comparison was made between the pre‐incubation and plate incorporation methods in both systems using some direct‐acting mutagens. Tests used only those strain/S9/chemical combinations where a response was expected. Historical control results accumulated during testing are also presented. Spontaneous and induced revertant colony counts for the µAmes system were consistently proportionate and approximately 1/20th those for the standard Ames test. Sensitivities of the two systems were found to be nearly identical in almost all cases for a wide variety of weak and strong inorganic and organic mutagens. Standardized procedures and increased reliability of the estimate of the background revertant frequency in the µAmes system means that the two systems give equivalent results and are expected to be highly predictive of one another. Environ. Mol. Mutagen., 2016. © 2016 Wiley Periodicals, Inc.
Source: Environmental and Molecular Mutagenesis - Category: Molecular Biology Authors: Tags: Research Article Source Type: research