Definition: MUSE exosomes
Exosomes are nanoscale extracellular vesicles (roughly 30–150 nm) enclosed in a lipid bilayer. They transport biological cargo — proteins, lipids, mRNA and microRNAs — between cells, and the membrane protects that cargo from enzymatic degradation in the extracellular space.
MUSE exosomes are the subset of these vesicles secreted by MUSE cells (multilineage-differentiating stress-enduring cells). MUSE cells are identified by the surface marker SSEA-3 and are characterized in the literature by their tolerance to physiological stress. Because the source population is defined and verifiable, the vesicles harvested from it can be documented lot by lot.
MUSE exosomes vs. MSC exosomes
The practical difference is the source cell, and it determines reproducibility. Generic MSC exosomes are isolated from heterogeneous mesenchymal stromal cultures, so composition can vary between batches. MUSE exosomes are collected from a verified SSEA-3-positive subpopulation, which makes source identity — and therefore lot-to-lot consistency — documentable rather than assumed.
For research procurement this matters more than marketing language: a supplier should be able to state the source cell, the characterization method, and provide a lot-specific Certificate of Analysis. Material without that documentation cannot support reproducible experimental work.
Specifications and characterization
Characterization of ExoTec™ MUSE exosomes follows established extracellular-vesicle methodology — particle sizing by Nanoparticle Tracking Analysis, tetraspanin marker profiling, protein quantification and sterility testing.
| Mean particle size (NTA) | 125–130 ± 40 nm |
|---|---|
| Purity | ≥97–99.5% |
| Concentration | ~100 ± 10 billion particles / mL |
| Exosomal markers | CD9 / CD63 / CD81 verified |
| Nucleic acid content | >400–1,876 ng/mL |
| Protein content | >800–1,800 µg/mL |
| Sterility / endotoxin | Sterile; <2.3–10 EU/mg |
| Formulation | Lyophilized powder (glycine / trehalose / mannitol, pH 7.4) |
| Storage | −20 °C long term; +2–8 °C shipping |
| Documentation | Lot-specific Certificate of Analysis (COA) |
Third-party validation: NanoSight (NTA), Lowry assay, Qubit analysis, sterility per European Pharmacopoeia. See the full product specifications for lot documentation.
Research applications
In published extracellular-vesicle literature, MUSE-derived vesicles are studied in contexts including skin and healthy-aging biology, tissue microenvironment support, inflammatory signaling, and hair-follicle microenvironment research. Mechanistic work examines pathways such as Wnt/β-catenin and PI3K/Akt.
These are areas of investigation, not established clinical outcomes. Further detail on pathway rationale is available on the exosome science page.
Handling and reconstitution
Material is supplied as a lyophilized powder in a glycine/trehalose/mannitol buffer (pH 7.4), which supports stability during transport and storage. Store at −20 °C or below for long-term use; +2–8 °C is adequate for shipping and short-term handling. Avoid repeated freeze–thaw cycles, which degrade vesicle integrity.
Frequently asked questions
What are MUSE exosomes?
MUSE exosomes are extracellular vesicles secreted by multilineage-differentiating stress-enduring (MUSE) cells — a distinct SSEA-3-positive subpopulation. Like all exosomes, they are nanoscale lipid-bilayer vesicles that carry proteins, lipids and microRNAs, and they are studied as vehicles of intercellular signaling.
How do MUSE exosomes differ from MSC exosomes?
The difference is the source cell. Generic MSC exosomes are collected from heterogeneous mesenchymal stromal cultures, whereas MUSE exosomes originate from a verified SSEA-3-positive MUSE cell population. Source-cell verification is what makes lot-to-lot composition reproducible and documentable.
What size are MUSE exosomes?
Mean particle size measured by Nanoparticle Tracking Analysis (NanoSight NTA) is 125–130 ± 40 nm, which is within the accepted size range for exosomes (roughly 30–150 nm).
How is purity of MUSE exosomes verified?
Purity of ≥97–99.5% is determined alongside tetraspanin marker profiling (CD9, CD63, CD81), particle counting by NTA, protein quantification (Lowry assay), and sterility testing per European Pharmacopoeia. Each lot ships with its own Certificate of Analysis.
How should MUSE exosomes be stored?
Supplied as a lyophilized powder in a glycine/trehalose/mannitol buffer at pH 7.4. Store at −20 °C or below for long-term stability; +2–8 °C is sufficient for short-term handling and shipping.
Are MUSE exosomes approved for clinical treatment?
No. MUSE exosomes supplied by Exosomus are for research use only (RUO) and remain investigational. They are not an approved medical treatment and are not intended to diagnose, treat, cure or prevent any disease.
Request an evaluation sample
Licensed research facilities and laboratories can request a MUSE exosome evaluation vial with its lot-specific Certificate of Analysis. See research kit pricing or contact info@exosomus.com.