The Ames Test


Nathan Goodson-Gregg and Elizabeth A. De Stasio

This published laboratory introduces students to the Ames test, an assay used to determine the mutagenic properties of chemical compounds, using a distinctly quantitative approach. Students must develop their own hypotheses, use proper positive and negative controls, perform their own serial dilutions, use sequencing and bioinformatics to assess their results, and finally, write up their findings in a formal laboratory report.

Originally published in GENETICS by Nathan Goodson-Gregg and Elizabeth A. De Stasio in 2009, and distributed here with their permission.

Genetics Concept(s) Addressed:

Nature of Genetic Material: Nature of Genetic Material: What are the molecular components and mechanisms necessary to preserve and duplicate an organism’s genome?
Genetic Variation: How do different types of mutations affect genes and the corresponding mRNAs and proteins?
Core Competencies Addressed:

Students should be able to implement observational strategies to devise a question.

Students should be able to generate testable hypotheses.

Students should be able to design an experiment using appropriate controls and appropriate sample sizes.

Students should be able to gather and evaluate experimental evidence, including qualitative and quantitative data.

Students should be able to generate and interpret graphs displaying experimental results.

Students should be able to critique large data sets and use bioinformatics to assess genetics data.

Students should be able to communicate experimental results effectively, including writing research papers and giving presentations.


Intermediate-level undergraduate
Activity Type:

Open-ended laboratory
Activity Length:

2 weeks (Week 1: 3 hrs; Week 2: 2 hrs)


Goodson-Gregg, N. and De Stasio, E. A. (2009) Reinventing the Ames Test as a Quantitative Lab That Connects Classical and Molecular Genetics. Genetics181: 23-21. DOI: 10.1534/genetics.108.095588


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