Why EV and exosome characterization data exists
There is no single visual test that confirms a preparation is made of extracellular vesicles. Instead, researchers and suppliers rely on a combination of particle-sizing and marker-detection methods, each of which measures a different property, to build a characterization profile for a given lot or product line.
The 2023 update to the Minimal Information for Studies of Extracellular Vesicles (MISEV2023) guidance recommends that any report of an EV preparation describe the source material, particle size distribution, particle concentration, and the specific markers tested, and that the term 'extracellular vesicle' be used instead of 'exosome' unless the biogenesis pathway specific to exosomes has actually been demonstrated for that preparation.
Nanoparticle tracking analysis (NTA) explained
Bio Xsomes characterization is reported to include NTA, ELISA and SP-IRIS. Ask for the methods, sample scope and analytical reports.
NTA figures, such as a stated particles-per-mL value, describe particle size and concentration only. They do not, on their own, confirm that particles originated from a specific cell type or carry a particular surface marker. If NTA data is reported alone, ask whether marker-based testing was also performed on the same sample.
ELISA and marker detection
ELISA is one of the methods reported for Bio Xsomes characterization, used to detect specific proteins such as the tetraspanin markers CD81 and CD9 associated with extracellular vesicles. Ask for the marker panel tested and the analytical report behind the claim.
Detection of these markers is one line of supporting evidence for EV identity under MISEV2023 guidance, not a performance claim about the product. Marker panels vary between suppliers and labs, so documentation should specify exactly which markers were tested, on which sample, and by which method.
Single particle interferometric reflectance imaging sensing (SP-IRIS)
SP-IRIS is one of the methods reported for Bio Xsomes characterization, used to identify markers on individual particles. Ask for the methods, sample scope and analytical report rather than relying on a summary figure.
If SP-IRIS data is reported, ask whether it was reported alongside NTA and ELISA results for the same lot, so the characterization picture can be reviewed as a whole rather than reviewing any single method's output in isolation.
Reading a characterization panel as a buyer
A buyer does not need to replicate the laboratory work to use this data responsibly. What matters is knowing what was actually measured, on which lot, by which method, and whether the figures quoted are lot-specific or a general statement about the product line.
It is reasonable to ask whether characterization was performed on the exact lot being purchased or on a separate reference batch, and to request the underlying report rather than accepting a one-line summary claim on a sell sheet.
What to request from a supplier
A short list of documentation requests covers most of what a buyer needs to evaluate a characterization claim.
FDA has stated that no FDA-approved exosome products exist. Exosome and other extracellular vesicle products are generally regulated as biologic drugs under section 351 of the PHS Act. Purchasing and clinical-use decisions belong to the physician, together with their own regulatory counsel.
These products are not FDA approved or licensed for any disease or condition. Information is for licensed healthcare professionals and is not medical or legal advice.
- The specific analytical methods used, such as NTA, ELISA or SP-IRIS, and the lab that performed them.
- Whether the reported particle concentration and markers apply to the lot being purchased or to a representative sample.
- The marker panel tested, including which tetraspanins or other surface proteins were assessed.
- Whether the supplier's literature follows MISEV2023 terminology and reporting conventions.
Frequently asked questions
Does NTA alone confirm a product contains exosomes?+
No. NTA measures particle size and concentration; it does not confirm the biological origin or marker profile of the particles. It is typically combined with marker-based methods like ELISA or SP-IRIS.
What does it mean if a product reports CD81 and CD9 markers?+
CD81 and CD9 are tetraspanin proteins commonly found on extracellular vesicles. Their detection is one piece of supporting evidence for EV identity under MISEV2023 guidance, not a stand-alone claim about what the product does.
Why do some suppliers say 'extracellular vesicle' instead of 'exosome'?+
MISEV2023 guidance recommends the broader term 'extracellular vesicle' unless the specific biogenesis pathway that defines an exosome has been demonstrated for that particular preparation.
Is there an FDA-approved exosome product?+
No. FDA has stated there are no FDA-approved exosome products. These products are generally regulated as biologic drugs under section 351 of the PHS Act. Purchasing and clinical-use decisions belong to the physician, together with their own regulatory counsel.