Evidence Tier
in_vitro
Last updated
Rung 5 on this site's ladder. A study in cells, tissue or a cell-free preparation, outside a living organism, with a control condition, a named assay, an identified cell line or tissue source, and the concentration reported in molar or mass units. Concentrations that could not be reached in a living body qualify only if that limitation is stated alongside the finding. The full criteria are at /evidence/rubric.
Flagged for specialist review
This entry describes something contested, or asserts a detail we have not been able to confirm against a settled source. It is published rather than withheld, with the flag visible, because an entry you can weigh beats a gap you cannot see.
Why it matters here
The binding affinities and potency numbers quoted in product copy usually come from this rung, and they describe a chosen concentration in a dish rather than anything a reconstituted vial delivers to a tissue.
What it is not
No dose, no route and no bioavailability may be inferred from an in vitro result. Active at 10 nanomolar is a statement about an assay, not about anything anyone could administer.
Also called
- in vitro
- cell culture
- cell-free
- test tube
Cell-free work, meaning binding assays with no cells at all, sits on this same rung, as does the everyday phrase test tube.
Compounds carrying this term
None on file yet. This term is in the controlled vocabulary but no compound record currently uses it — which is a statement about our coverage, not about the term.