Fresh vs Frozen Stem Cells: How to Judge Cell Quality

What Does the Freeze-Thaw Cycle Change?

Cryopreservation stores cells in liquid nitrogen with a protective agent so they can be banked and shipped. It is a standard laboratory technique, and it has a real use: it lets a laboratory hold stock and deliver on a schedule. The trade-off is the thaw. A 2014 study from the Karolinska Institutet (Moll et al., Stem Cells) compared freeze-thawed mesenchymal stem cells with cells harvested from continuous culture and found that the thawed cells had impaired immunomodulatory and blood-regulatory properties. An earlier laboratory study (François et al., Cytotherapy, 2012) linked the thaw to a heat-shock response in the cells. The findings are not uniform: a 2019 study (Tan et al., Scientific Reports) found similar viability at thaw and comparable potency in laboratory assays and in an animal model, although the thawed cells showed more apoptotic cells beyond four hours.

A fresh product skips that step: the cells are released from culture and administered without being frozen in between. That removes one source of variability, but it requires tight coordination between the laboratory and the clinic, because a fresh batch has a short window of use.

The honest question is not "fresh or frozen?" in isolation. It is: if frozen, what was the viability after thawing, measured on this batch? If fresh, how long between release and administration? Either answer should be specific.

What Is a Passage Number, and Why Passage 3?

A treatment dose is counted in millions of cells, and no tissue sample contains that many. The cells are therefore expanded in culture. Each time the culture is split into new vessels, that is one passage. Passage 1 is the first expansion; passage 10 means the cells have been split ten times.

Every passage moves the cells a little further from the tissue they came from. In a study of human MSCs expanded over 7 to 12 passages (Wagner et al., PLoS One, 2008), the cells enlarged, showed reduced expression of some surface markers and eventually stopped dividing, and the changes in gene expression built up continuously with each passage rather than appearing only at the end. Early passages keep more of the original characteristics.

Healthi Life releases cells at passage 3. It is early enough to keep early-passage characteristics and late enough to reach the doses our protocols use (5 to 15 million cells for a local protocol). A clinic that cannot tell you the passage number of its cells cannot tell you how far they were expanded.

What Viability Should a Stem Cell Batch Deliver?

Viability is the percentage of living cells in a batch, measured at the moment the laboratory releases it. It is a property of that batch, not of a brand or of a laboratory in general, so the figure that matters is the one written on the certificate of analysis for the cells you receive. A laboratory sets a release criterion in advance: a batch that measures below it is not released. At Healthi Life, each batch is released only after testing confirms 98-99% cell viability at release, with a minimum release threshold of 95%, documented on the partner laboratory's certificate of analysis.

For a frozen product, the question changes. The viability measured before freezing says nothing about the cells after the thaw, so ask for the post-thaw viability, measured on the same batch after thawing and shortly before administration. Viability describes the product; it does not predict how an individual will respond.

Where Do the Cells Come From?

Mesenchymal stem cells (MSCs) can be isolated from several tissues, and the source shapes three things: the logistics of collection, the screening the donor or patient needs, and what the cells reflect. The minimal criteria published by the International Society for Cellular Therapy (Dominici et al., Cytotherapy, 2006) define an MSC by laboratory properties (it adheres to plastic, carries a set of surface markers and can form bone, cartilage and fat cells in culture), not by the tissue it came from.

Healthi Life uses umbilical cord MSCs from Wharton's jelly, prepared by an ISO 9001:2015-certified, GMP-grade partner laboratory. Donors are 20 to 35 years old and are screened on their medical history and risk factors, on two generations of family history (genetic disease, cancer, infectious disease) and by infectious disease testing. Each batch is then tested for viability, sterility and contamination, tumorigenicity, MSC identity markers and cartilage-lineage markers. Ask any clinic how its donors are screened, and which tests were run.

How Does a Clinic Prove Cell Quality?

Every clinic describes its cells as high quality. The difference is what it can show on paper, for the batch you receive rather than for the laboratory in general. Here is what to ask, what a real answer looks like, and what we answer.

A complete certificate of analysis also reports sterility, mycoplasma and endotoxin testing and the cell identity markers; ask which of those results were complete before the batch was released. The International Society for Cellular Therapy has argued that release testing should also include a functional measure of what the cells do, not only a count of living cells (Galipeau et al., Cytotherapy, 2016), which is one reason a single viability percentage is never the whole picture. For the wider checklist (physician and facility licensing, regulatory category, pricing and follow-up), see our guide on how to choose a stem cell clinic in Thailand.

When Are Chondrogenic MSCs Used?

Chondrogenic MSCs are the same mesenchymal stem cells, guided toward the cartilage lineage in culture before they are introduced into the joint. They are used in cartilage-directed joint protocols, sometimes combined with an IV component. We offer 5, 10 or 15 million chondrogenic MSCs per knee. The physician selects the dose after assessment; the laboratory matches it to the osteoarthritis grade. The quality criteria above apply in the same way: fresh or frozen, passage number, viability at release and source are asked for the chondrogenic batch as for any other.

The chondrogenic protocol is not an upgrade that suits everyone, and human evidence for pre-differentiated MSCs is still limited. The decision follows a consultation and a review of imaging (MRI or X-ray), and the physician may recommend a standard protocol, a chondrogenic one or neither. Suitability for MSC therapy requires individual physician consultation and medical screening before treatment. For the full joint program, see stem cell therapy for osteoarthritis in Bangkok.

How Often Can Stem Cell Therapy Be Repeated?

There is no standard repeat schedule. Most people are treated again after one to three years; the interval depends on the severity of the condition and on the goal set at consultation. The decision is made at follow-up review, not set on a calendar at the first visit. Be cautious of any plan that sells a series of sessions in advance, before the first protocol has even been reviewed.

Follow-up review means the physician compares the current assessment with the one made before the first protocol: symptoms, function, imaging where it is relevant, and laboratory work. A baseline blood panel before a first protocol makes that comparison possible later; our health check-up is one way to establish it. If the review shows no reason to repeat, the answer is not to repeat, and that is a valid outcome of the visit.

What Does Stem Cell Therapy Cost at Healthi Life, Bangkok?

Prices depend on the protocol and the cell dose. They are published in full; there is no crossed-out price and no time-limited offer.

Protocol, dose and final price are confirmed by the physician after consultation. Full program details: stem cell therapy in Bangkok.

Which Five Questions Should You Ask Any Clinic?

1. Are the cells fresh or cryopreserved? If frozen, what was the viability after thawing, for this batch?
2. At what passage number are the cells released?
3. What is the viability release criterion, and can I see the certificate of analysis for my batch?
4. What is the cell source, and how is the donor screened?
5. Which named physician assesses me, prescribes the protocol and follows up?

Specific, written answers are the standard. Vague answers are information too.

References

1. Moll G, et al. Do cryopreserved mesenchymal stromal cells display impaired immunomodulatory and therapeutic properties? Stem Cells. 2014;32(9):2430-2442. doi:10.1002/stem.1729
2. François M, et al. Cryopreserved mesenchymal stromal cells display impaired immunosuppressive properties as a result of heat-shock response and impaired interferon-γ licensing. Cytotherapy. 2012;14(2):147-152. doi:10.3109/14653249.2011.623691
3. Tan Y, et al. Thawed mesenchymal stem cell product shows comparable immunomodulatory potency to cultured cells in vitro and in polymicrobial septic animals. Scientific Reports. 2019;9:18078. doi:10.1038/s41598-019-54462-x
4. Wagner W, et al. Replicative senescence of mesenchymal stem cells: a continuous and organized process. PLoS One. 2008;3(5):e2213. doi:10.1371/journal.pone.0002213
5. Dominici M, et al. Minimal criteria for defining multipotent mesenchymal stromal cells. The International Society for Cellular Therapy position statement. Cytotherapy. 2006;8(4):315-317. doi:10.1080/14653240600855905
6. Galipeau J, et al. International Society for Cellular Therapy perspective on immune functional assays for mesenchymal stromal cells as potency release criterion for advanced phase clinical trials. Cytotherapy. 2016;18(2):151-159. doi:10.1016/j.jcyt.2015.11.008

Dr. Sarassawadee Suwanjinda (Dr. Petch)

Verified Physician

Co-Founder & Chief Medical Strategy Officer

International Board of Lifestyle Medicine (IBLM) Diplomate

Dr. Sarassawadee Suwanjinda (Dr. Petch) is Co-Founder & Chief Medical Strategy Officer at Healthi Life, an International Board of Lifestyle Medicine (IBLM) Diplomate. She leads the longevity programs — biological-age and biomarker-driven protocols designed and re-tested over time.

Longevity MedicineBiomarkersBiological AgeFunctional Medicine

View full profile →LinkedIn