COMET test:
The COMET assay is a reference method for assessing the ability of a cosmetic ingredient or product to cause DNA damage, a key indicator of genotoxic risk. In a strictly controlled environment, cells grown in the laboratory are exposed to the product. Tested under conditions that replicate realistic exposure.
The COMET test (or single-cell gel electrophoresis) is a reference method recognized by the OECD (TG 489) for measuring DNA damage induced by a cosmetic ingredient or product. In a laboratory environmentIn a strictly controlled environment, cultured human or animal cells are exposed to the test substance at realistic concentrations. If the compound causes DNA breaks or changes, these lesions fragment the genetic material.
When DNA is damaged, it fragments. During electrophoresis, these fragments migrate outside the cell nucleus and form a characteristic structure called a «comet»: the central part represents the head (intact DNA), while the damaged fragments form the tail. The length, intensity, and extent of this tail are measured precisely in order to assess the level of damage suffered by the cells.
This extremely sensitive test can detect very slight genetic alterations that are sometimes invisible using other methods. It is an indispensable tool for validating the toxicological safety of raw materials, natural active ingredients, and innovative formulations intended for the Swiss and European markets, where genotoxicity is subject to strict regulatory requirements.
The COMET assay is currently the most sensitive and widely accepted tool for demonstrating the absence of genotoxicity in a cosmetic ingredient or formulation. By combining its high analytical resolution with strict compliance with Swiss, European, and UK requirements, it enables manufacturers to ensure the safety of their products, speed up the notification number process, and gain the trust of consumers concerned about the genetic safety of their skincare products.
Principle of the technique
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Cell coating – After exposure, the cells are incorporated into an agarose gel.
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Lysate – An alkaline solution denatures the membranes and releases the DNA.
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Electrophoresis – Under the action of an electric field, DNA fragments migrate out of the nucleus.
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Formation of the «comet» – Intact DNA forms the head, while the fragments migrate and create a tail.
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Analysis – Length, intensity, and head-to-tail ratio are quantified using imaging software. These parameters (tail size, % of DNA in the tail, damage index) provide an accurate measure of genotoxic potential.
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Exceptional sensitivity : it detects very low levels of genetic damage, often invisible with other methods (e.g., micronucleus).
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Broad applicability : suitable for raw materials, natural active ingredients, biotechnological extracts, and final formulations.
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Regulatory compliance : Swiss (OCos/OSAV) and European (Regulation (EC) No. 1223/2009) authorities require a genotoxicity assessment for ingredients intended for prolonged skin use or use near mucous membranes.
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Integration into the DIP/PIF : the results are directly transferred to the Product Information File (DIP) or the Product Information File (PIF), strengthening the credibility of the marketing application.