The ISCT published minimal criteria in 2006 to define a mesenchymal stromal cell with a testable, three-part bar rather than a single definitive test.
Each of the three criteria addresses a different question: plastic adherence is a basic culture behavior, the marker panel addresses cell-surface identity, and tri-lineage differentiation addresses functional multipotency. A cell population must satisfy all three to be called an MSC under the ISCT framework. Meeting only one or two is not sufficient.
Because the criteria require live-cell culture assays, they can only be verified on a product that still contains viable, proliferative cells. A 2026 analysis of six commercial WJ products found low cell counts and viability with only rare viable MSCs, and a 2021 study found no colony-forming MSCs in five cord products. Buyers can use the three-part framework as a checklist when asking a supplier what evidence, if any, accompanies an MSC-related claim.
The three-part framework gives buyers a concrete checklist for questioning any supplier claim that a product contains MSCs.