When this test applies
Required for essentially every patient-contacting device under ISO 10993-1:2025, regardless of contact type or duration. If you are running any biological evaluation at all, this is in it.
When to run it
Early. It is fast and inexpensive relative to the rest of the battery, and a failure here changes your material decisions before you have spent money on sensitization or systemic toxicity.
What a pass tells you
That the extract produced no significant cellular reactivity under these conditions. It is evidence of the absence of an acute cytotoxic leachable — not proof the material is biocompatible.
What it does not tell you
Nothing about sensitization, irritation, genotoxicity or systemic effects. Those are separate endpoints with separate tests. Passing cytotoxicity does not substitute for any of them.
Method
1× MEM elution against L-929 mouse fibroblasts. The extract is prepared in cell culture medium at 37 °C ± 1 °C for 24 h ± 2 h, applied to a confluent monolayer, and graded 0–4 against negative, positive and reagent controls. A grade of 2 or above is a reactive result.
Choosing a source
Domestic and international laboratories are both ISO/IEC 17025 accredited and GLP certified. The choice affects price and turnaround, not the method or the standard — it is a sourcing decision, not a regulatory one.
Usually ordered alongside
For a surface-contact device the baseline battery under ISO 10993-1:2025 normally also includes sensitization and irritation. 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.
