When this test applies
Required for devices with prolonged or long-term contact, and wherever the chemistry raises a genotoxic concern that cannot be closed out on the available data. Under ISO 10993-1:2025 the genotoxicity endpoint can often be addressed by chemical characterisation and toxicological risk assessment instead of testing — which is worth asking before commissioning it. This is the mammalian-cell mutation arm of the ISO 10993-3 battery, and it detects both gene mutation and some chromosomal events — which is why it is often chosen as the second assay after Ames.
When to run it
After chemical characterisation, not before. If extractables and leachables plus an ISO 10993-17 assessment close the endpoint out, the study is avoided entirely. If they do not, the chemistry tells the laboratory what it is looking for.
What a pass tells you
That there was no statistically significant, dose-related increase in mutant frequency at the tk locus relative to the concurrent negative control, with and without S9 metabolic activation, and with the positive controls responding as expected.
What it does not tell you
A negative result here does not substitute for the bacterial reverse mutation assay, which regulators normally expect alongside it, nor for the chromosomal aberration assay where clastogenicity is the specific concern. ISO 10993-3 generally expects a battery rather than a single assay, so no one result closes genotoxicity on its own.
Method
Testing per ISO 10993-3:2014. A single extract is prepared at 90 mL and dosed onto L5178Y mouse lymphoma cells with and without S9 metabolic activation; mutation at the tk locus is scored against concurrent controls. Extraction ratio follows ISO 10993-12: 6 cm²/mL for material under 0.5 mm thick, 3 cm²/mL at 0.5 mm or thicker, or 0.1 to 0.2 g/mL where surface area is indeterminate.
Where it runs
This method is internationally sourced. The laboratory is ISO/IEC 17025 accredited and GLP certified, and the report is issued under Groenakker cover, in Groenakker’s report template or in your document template on request at no extra cost.
Usually ordered alongside
The bacterial reverse mutation assay (Ames) and the chromosomal aberration assay complete the ISO 10993-3 battery. Chemical characterisation with an ISO 10993-17 assessment is the alternative route and should be considered first.
