Spiral Salmonella assay: Validation against the standard pour-plate assay

Diehl, Marilyn S.; Fort, Farrel L.

doi:10.1002/(sici)1098-2280(1996)27:3<227::aid-em8>3.0.co;2-b

Cited by 13 publications

(2 citation statements)

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“…Forward mutation systems have also been proposed that have the advantage that only a single strain of the bacterium needs to be tested [Miller et al, ]. The second group of screens employ the standard strains listed by OECD but use a different format than the standard plate incorporation and pre‐incubation methods. These include systems where a concentration gradient of the test compound is generated across an agar plate, e.g., the spot test [Maron and Ames ], a wedge/slope method [McMahon et al, ] and the spiral plate method [de Flora , Diehl and Fort , Claxton et al, ]. A modified pre‐incubation method can be used to detect the mutagenicity of chemicals in limited supply; in this case small volumes of the test solution are pre‐incubated with a concentrated suspension of the bacteria before plating out using the standard volumes of top and bottom agar [Kado et al, ].…”

Section: Introductionmentioning

confidence: 99%

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

Proudlock¹,

Evans²

2016

Environ and Mol Mutagen

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"Ames" bacterial mutation tests are widely performed for evaluation and registration of new materials including industrial chemicals, agrochemicals, medical devices, pharmaceuticals, pharmaceutical impurities and other materials. Tests are used to predict their potential long-term adverse health effects (including carcinogenicity). Given their importance, pre-screening 'miniaturized' versions have been developed which allow higher throughput and use less test material, including the widely-employed 24-well micro-Ames (µAmes) test which uses 20 times less material. However, little quantitative information has been published on the methodology or sensitivity of this system. 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. 57:687-705, 2016. © 2016 Wiley Periodicals, Inc.

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Section: Introductionmentioning

confidence: 99%

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

Proudlock¹,

Evans²

2016

Environ and Mol Mutagen

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“…Modifications have been made to increase the sensitivity and to Ž simplify the detection Cote et al, 1995;Taylor et al,´. 1995;Diehl and Fort, 1996 . In the mutachromoplate test, mutations are determined spectrophotometrically Ž by a change in color from purple to yellow Hubbard et . al., 1994 .…”

Section: Test Principlementioning

confidence: 99%

Selection of genotoxicity tests for risk assessment of effluents

Maagd

Tonkes

2000

Environ. Toxicol.

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Genotoxicity is one of the parameters within the whole effluent environmental risk procedure, an effect‐based procedure developed in the Netherlands to supplement classical substance‐specific risk assessment of effluents. To implement the genotoxicity parameter, one or more tests have to be selected for routine use on effluents. This paper deals with problems and considerations encountered during selection of genotoxicity tests. Tests were judged on: relevance, validation, detected genotoxic lesions, quantitative sensitivity, convenience, and cost‐efficiency. Based on criterion detected genotoxic lesions and on criteria convenience and cost‐efficiency, it is recommended to use at least a bacterial test which makes use of detection of the SOS pathway which is induced upon the occurrence of DNA damage. The criterion quantitative sensitivity is used in a laboratory study on effluent samples to select the most appropriate bacterial SOS pathway test. The range of detected genotoxic endpoints can be expanded by also including a more expensive test that detects clastogenesis and/or aneuploidy. In that case it seems wise first to establish the added value of such a test for the risk assessment of effluents, before deciding on further use. Furthermore, it is concluded that the presently available information on relevance and validation is of limited use for test selection. Finally, recommendations are made on test protocols and on pretreatment of effluent samples to optimize genotoxicity tests for effluent samples. Recommendations include data analysis, detection of the interference of cytotoxicity, extraction, the use of S9, concentration procedures, and filtration. © 2000 John Wiley & Sons, Inc. Environ Toxicol 15: 81–90, 2000

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