The ToxTracker assay is a stem cell-based reporter assay for mechanistic genotoxicity hazard screening. The assay combines six fluorescent reporter genes that are selectively activated by different cellular signaling responses. Activation of the reporter genes is measured by flow cytometry. The differential induction of each reporter compared to the solvent control cells is used to predict genotoxicity as well as the genotoxic mode-of-action of the test compound.
Draft new Test Guideline on the ToxTracker gene reporter assay for genotoxic hazard identification
- Submission period
- 15 Dec 2025 - 4 Feb 2026
Background public consultation
Project description
The project to develop an OECD Test Guideline on the ToxTracker assay was proposed by the Netherlands and included in the Test Guideline Programme workplan in April 2025. It builds on a previous project in which a validation study of the assay was carried out and a validation report developed. The results underwent an independent peer review, organised by the Secretariat in 2023. In July 2025, the draft Test Guideline was submitted to the Working Party of the National Coordinators of the Test Guidelines Programme (WNT) for a first commenting round. The lead addressed the comments received and revised the draft Test Guideline with the support of the OECD Expert group on genotoxicity.
How to contribute
The draft new Test Guideline on the ToxTracker gene reporter assay for genotoxic hazard identification is currently under a second commenting round by the Working Party of the National Coordinators of the Test Guidelines Programme and open for comments from the public at the same time. Interested parties are invited to submit comments to/contact their National Coordinators at least a week before 4 February 2026.
Documents for public comments
