Alive is not the same as effective
Mesenchymal stem cells, or MSCs, are often described by how many there are and whether they are alive. Both are worth knowing, but neither says whether the cells will perform the biological activity they are meant to.
A lot can be fully viable and still fall short, for example after too many passages or a change in culture conditions.
What potency asks
Potency is a functional question: does this lot do what it is supposed to do? The honest answer depends on the intended use, so the assay should be chosen with that use in mind.
For an application built on the factors cells secrete, a potency assay might test a response to those secretions. For a different use, a different readout is appropriate. There is no single universal test.
Why potency data builds trust
Potency data also makes lots comparable over time. A programme that measures it from the first batch builds a record of how the cells behave across donors, passages and process changes.
That record is far easier to defend to a collaborator or a regulator than a collection of cell counts, and it often reveals problems while they are still cheap to fix.
- Cell count and viability describe the cells, not what they do.
- Potency is a functional test chosen to match the intended use.
- Measuring potency from the start makes every later lot comparable.
Common questions
What is the difference between viability and potency?
Viability says whether cells are alive. Potency says whether they can perform the biological activity needed for their intended use.
Is there one standard potency assay for MSCs?
No. The best assay depends on the intended use, so it is usually agreed with the client at the start of a programme.
Why does potency change between lots?
Donor, tissue source, number of passages and culture conditions can all shift cell behaviour, which is why potency is measured on every lot.
