Souls Test – OECD 471

The Ames test is an essential method in genetic toxicology. It assesses the mutagenic potential of a substance, i.e., its ability to cause point genetic mutations. This test is based on the use of specific strains of Salmonella typhimurium deficient in histidine synthesis.

Used in the cosmetic, chemical, pharmaceutical and food industries, the Ames test is a key step in assessing the safety of ingredients, natural or formulated substances. It is recommended by the OECD under guideline 471 and recognized in regulatory procedures (REACH, CLP, etc.).

Purpose of the test

• Detect reversible mutations (point mutations) caused by a substance
• Predict carcinogenic or genotoxic potential
• Evaluate plant extracts, chemical compounds, cosmetic ingredients, or drugs
• Meet regulatory requirements for new product registration

Methodology

The test uses several bacterial strains of Salmonella typhimurium , which cannot grow without histidine. In the presence of the test substance, if colonies appear on a medium lacking histidine, this means that mutations restore the synthetic capacity – indicating mutagenic activity.

Two experimental conditions are systematically evaluated:

• Without metabolic activation (direct test on bacteria)
• With metabolic activation (S9 mix) to simulate human hepatic metabolism (case of pro-mutagens)

The results are interpreted according to the number of revertant colonies compared to the control, with calculation of a mutation index.

Industrial applications

• Cosmetics: safety of active ingredients, raw materials
• Pharmaceutical: screening of new molecules
• Fine chemistry: toxicological classification
• Plants / nutraceuticals: plant extracts, bioactive compounds
• Food industry: additives, contaminants

Why go through YesWeLab?

YesWeLab connects you with laboratories specialized in regulatory testing, accredited and experienced in carrying out the Ames test according to OECD 471. Our partners have all the standardized strains, metabolic activation systems (S9) and proven know-how in toxicological interpretation.

Through our digital platform, you benefit from centralized analysis management, personalized scientific support, and rapid processing of your requests. Since 2020, dozens of manufacturers have trusted us to secure their products.

See also:

• Micronucleus Test – OECD 487
• Genotoxicity test 
• HET-CAM test