There are a lot of exosome suppliers now. Most of them will tell you their particle count. Few will tell you the rest. Here is what we think matters, and how we do it.
1. A named, screened source
Our vesicles are isolated from human umbilical-cord mesenchymal stromal cells from consenting, screened donors, expanded in xeno-free media with no fetal bovine serum. Each lot is traceable to its donor and culture batch. We can tell you the passage number of the cells that made it, which matters because cells that have been expanded too many times change what they secrete.
2. Characterisation, not just a count
Every lot is characterised along the lines the International Society for Extracellular Vesicles sets out in its MISEV guidance. That means size distribution by nanoparticle tracking analysis, confirmation of the tetraspanin markers CD9, CD63 and CD81, absence of markers that indicate cell debris, transmission electron microscopy, and a particle-to-protein ratio as a purity measure. A particle count on its own tells you how many things of roughly the right size are in the vial. Our certificate of analysis tells you what they are.
3. Sterility and safety testing
Each lot is tested for sterility, endotoxin and mycoplasma before release, and the results are on the certificate. Donor screening covers the standard panel of transmissible infections. Manufacturing takes place in an ISO-classified clean room in California under a documented quality system.
4. Stability you can rely on
Vesicles fall apart in a warm vial. We offer our products freeze-dried, which keeps them stable at refrigerator temperature for the labelled shelf life and tolerant of a few days at room temperature in transit. Liquid formats ship on ice with a temperature indicator in every box, and we ask clinics to check it before they sign. More on this in how we ship.
5. Documentation and honesty about claims
Our products are cosmetic-grade, for topical professional use after procedures. We do not sell anything for injection and we do not make drug claims. If a supplier tells you their exosomes are "FDA-approved", treat everything else they say with caution: no exosome product is. We would rather earn your trust by telling you the limits than lose it later.
What we ask of you
We open accounts for licensed practices and research organisations only, and we verify licensure before shipping. It slows things down slightly and it is the right way to do it. If that sounds like the kind of supplier you want, start with the intake form and we will send pricing, a sample certificate of analysis and a storage and handling guide.