Format

Send to

Choose Destination
Environ Mol Mutagen. 2018 Jul;59(6):488-501. doi: 10.1002/em.22195. Epub 2018 Apr 18.

Miniaturization of the microsuspension Salmonella/microsome assay in agar microplates.

Author information

1
School of Technology, State University of Campinas (UNICAMP), Limeira, SP, Brazil.
2
Pharmaceutical Sciences Faculty, University of São Paulo (USP), São Paulo, SP, Brazil.
3
Department Effect-Directed Analysis, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
4
RWTH University of Aachen, Aachen, Germany.

Abstract

The Salmonella/microsome assay (Ames test) is the most widely used mutagenicity test for the evaluation of pure chemicals and environmental samples. There are several versions of protocols available in the literature, including those that reduce the amount of sample needed for testing with liquid and agar media. The microsuspension version of the Salmonella/microsome assay is more sensitive than the standard protocol. It is performed using 5-times concentrated bacteria and less sample and S9 mixture, but still uses conventional Petri dishes (90 × 15 mm). It has been extensively used for environmental sample testing, including in effect-directed analysis (EDA). The objective of this study was to miniaturize the microsuspension assay using 12-well microplates instead of the conventional plates. For validation of this miniaturization, thirteen mutagenic compounds were tested using three Salmonella strains that were selected based on their different spontaneous reversion frequencies (low, medium, and high). The conditions of the miniaturized procedure were made as similar as possible to the microsuspension protocol, using the same testing design, metabolic activation, and data interpretation, and the tests were conducted in parallel. The miniaturized plate assay (MPA) and microsuspension procedures provided similar sensitivities although MPA is less laborious and require less sample and reagents, thereby reducing overall costs. We conclude that the MPA is a promising tool and can be particularly suitable for environmental studies such as EDA or monitoring programs. Environ. Mol. Mutagen. 59:488-501, 2018.

KEYWORDS:

Ames test; MPA; effect-directed analysis; monitoring studies; mutagenicity; validation

PMID:
29668047
DOI:
10.1002/em.22195

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center