How are MSC products tested before treatment?
- Written by
- StemCell Longevita Editorial Team
- Medically reviewed by
- Prof. Dr. Erdal Karaöz TeamProfessor of Histology and Embryology · Medical Director, Center for Regenerative Medicine
- Last reviewed
- Next scheduled review
How we evaluate evidence · Conflict-of-interest disclosure · Editorial standards
Between the donor and the patient, a cell product is tested repeatedly. The document that summarises the final tests is the certificate of analysis (CoA). If a provider cannot show you one, the rest of the conversation is guesswork.
Testing across the process
| Stage | What is checked |
|---|---|
| Donor screening | Consent, medical and travel history, serology for HIV, hepatitis B and C, syphilis and other agents per national requirements |
| Tissue acceptance | Tissue integrity, transport conditions, traceability from donation to batch |
| In-process | Growth kinetics, morphology, contamination checks, passage number control |
| Release | Identity, viability, sterility, endotoxin, mycoplasma, potency — the CoA tests |
| Post-thaw | Viability re-checked after thawing, within the administration window |
How is an MSC product tested before it is given to a patient?
Before release, a mesenchymal stem cell product is tested for identity by surface-marker profile, viability by cell counting, sterility by culture, endotoxin by LAL assay and mycoplasma by PCR, with cell dose confirmed. A batch that fails any criterion is not released. Results are recorded on a release certificate that is issued to the patient with the treatment report.
Key facts
- Identity
- CD73/CD90/CD105 positive, haematopoietic markers negative
- Viability
- Measured per batch, minimum threshold applied
- Sterility
- Culture-based testing
- Endotoxin
- LAL assay within defined limit
- Mycoplasma
- PCR
What we know
- These five tests are the internationally recognised minimum for a cell therapy release panel.
- Failing batches are discarded rather than administered with caveats.
What remains uncertain
- Potency assays for MSCs are not standardised across the field, so 'potency' claims differ between laboratories.
Medically reviewed questions
This summary is general medical information, not medical advice, and not a promise of benefit. Figures are quoted ranges, confirmed in writing after a medical review.
Medically reviewed by: Prof. Dr. Erdal Karaöz · Last updated: · Editorial and evidence policy
The release tests explained
Each of these is unpacked further on the release criteria page.
- Identity — surface marker profile confirming the cells are MSCs (positive for CD73, CD90, CD105; negative for haematopoietic markers such as CD34 and CD45), per ISCT criteria.
- Viability — the proportion of living cells in the dose, measured before release and again after thaw.
- Sterility — no bacterial or fungal growth, by a validated method.
- Endotoxin — bacterial toxin below a defined limit; a sterile product can still be pyrogenic.
- Mycoplasma — a contaminant invisible on standard sterility testing.
- Karyotype or genetic stability — checked for expanded cells to exclude abnormal changes in culture.
- Potency — a functional assay showing the cells still do something measurable, such as suppressing T-cell proliferation. This is the test weak providers skip.
Reading a certificate of analysis
- Does it name the batch, the date and the product — and does the batch number match what you receive?
- Does it list a specification for each test, and the result against it?
- Is potency there, or only viability?
- Who released it, and is that person independent of production?
- Was post-thaw viability measured, or only pre-freeze?
Frequently asked questions
What viability should I expect?
Specifications vary by product and route; a defined threshold should be written into the release criteria and measured again after thawing. Ask for the specification, not a marketing number.
Why does potency matter so much?
Because cells can be alive and sterile yet functionally exhausted after too many passages. Potency is the only release test that asks whether they still work.
Can I get a copy of my own batch's CoA?
You should be able to. Ask for it as part of your discharge documentation.
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