When this test applies
ISO 10993-1:2025 flags genotoxicity for devices with prolonged or long-term contact. The mouse lymphoma assay is the mammalian cell mutation arm of the ISO 10993-3 battery: it detects both gene mutation and chromosomal events in mammalian cells, and completes the in vitro battery alongside the Ames and chromosomal aberration assays.
When to run it
After cytotoxicity, with the material and process locked, and in the same campaign as the other genotoxicity assays so that extract preparation is shared. At 12 to 13 weeks it sets the critical path for the battery. Where a toxicologist can address genotoxicity from chemical characterisation data, confirm that first.
What a pass tells you
That neither extract produced an induced mutant frequency exceeding the Global Evaluation Factor above the concurrent background, and no concentration-related increase — a negative result under ISO 10993-3 and OECD 490.
What it does not tell you
A negative result addresses mutation in mammalian cells under these conditions. It does not replace the Ames assay for bacterial gene mutation where a regulator expects it, and it says nothing about cytotoxicity, sensitization, irritation or systemic effects.
Method
Testing per ISO 10993-3:2014 and OECD 490. Two extracts are prepared — 0.9% sodium chloride (polar) and sesame oil, NF (non-polar) — and applied to L5178Y tk+/− mouse lymphoma cells with and without S9 metabolic activation, against concurrent negative and positive controls. Mutant frequency at the thymidine kinase locus is determined and compared with the Global Evaluation Factor. 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 (OUS). The laboratory is ISO/IEC 17025 accredited and GLP certified, and the report is issued under Groenakker’s ISO 13485:2016 certified quality system, in Groenakker’s report template or in your document template on request at no extra cost.
Usually ordered alongside
The Ames assay (GRK-4005-01) and chromosomal aberration (GRK-4005-02) complete the in vitro battery. Cytotoxicity should already be clear. If you do not yet have a biological evaluation plan, that is the place to start — a BEP typically removes tests from a list rather than adding them.
