Miniaturization of the microsuspension Salmonella/microsome assay in agar microplates

Author(s)

Zwarg, Jose Ricardo R. M. ^[1] ; Morales, Daniel A. ^[1] ; Maselli, Bianca S. ^[2] ; Brack, Werner ^{[3, 4]} ; Umbuzeiro, Gisela A. ^{[2, 1]}

Affiliation

^[1] State Univ Campinas UNICAMP, Sch Technol, Limeira, SP - Brazil

^[2] Univ Sao Paulo, Fac Pharmaceut Sci, Sao Paulo, SP - Brazil

^[3] UFZ Helmholtz Ctr Environm Res, Dept Effect Directed Anal, Leipzig - Germany

^[4] Rhein Westfal TH Aachen, Aachen - Germany

• Document type: Journal article
• Source: Environmental and Molecular Mutagenesis; v. 59, n. 6, p. 488-501, JUL 2018.
• Web of Science Citations: 4

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 x 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. (c) 2018 Wiley Periodicals, Inc. (AU)

• FAPESP's process: 15/24758-5 - Virtual effect directed analysis for mutagenicity characterization of relevant environmental samples
• Grantee: Gisela de Aragão Umbuzeiro
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/16956-6 - Diagnostic strains of the Salmonella / microsome assay as a potential tool in effect directed analysis: application in a solution-oriented project
• Grantee: Gisela de Aragão Umbuzeiro
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/11399-7 - Miniaturization of the Salmonella/microsome in microsuspension assay
• Grantee: José Ricardo Rossetto Martins Zwarg
• Support Opportunities: Scholarships in Brazil - Scientific Initiation