Quality reference
Reading an Exosome Certificate of Analysis
Reviewed by ExaVeyra Sciences editorial team · Updated 29 August 2026
A certificate of analysis is the densest document a supplier will send you and the one most often skimmed for the word "pass". Read structurally rather than line by line it takes about three minutes, and most of what it can tell you comes from three passes that have nothing to do with the values.
This page is the map. Each assay is handed off to the reference that covers it properly, so nothing here is a summary of something explained better elsewhere.
First pass: does this document describe your material
Before any result matters, establish that the certificate belongs to the vial in front of you. A lot number on the document that matches the lot on the container is the whole of this pass.
A certificate with no lot number is a specification sheet describing what the product is supposed to be. That is a useful document and a different one, and the two get sent interchangeably.
Second pass: start with the test list
The most common misreading is treating the absence of a result as a pass. A certificate reports the assays that were run, so an attribute nobody measured simply does not appear, and its absence looks identical to a clean result.
Read the left-hand column first and ask what is missing from it. That question is answerable in seconds and it is where most of the information is.
Third pass: check that each result names its method
Particle counts and marker percentages are not portable between instruments. The same preparation measured two ways produces two different numbers, and neither is wrong.
So a result without a named method cannot be set against a competing quote. Method first, then numbers, is the order that makes two certificates comparable at all.
Where each line is covered properly
| Section of the certificate | What it establishes | Covered in |
|---|---|---|
| Identity and marker panel | That the material is vesicular in origin, to the extent the fraction reported supports it. | The tetraspanin marker panel reference. |
| Particle concentration and size | How many detectable particles were present, under one method with one detection floor. | The particle counting reference. |
| Sterility, endotoxin, mycoplasma | Three separate contamination questions, each with its own blind spot. | The contamination testing reference. |
| Storage and handling conditions | The condition the material was validated to hold, which the label governs. | The cold chain reference. |
| Overall documentation completeness | Whether the package reports what a reporting standard says a study should. | The MISEV2023 reference. |
For a longer walkthrough of the values themselves, assay by assay, the chemist’s guide linked below covers that ground and this page does not repeat it.
What sits alongside the certificate
A complete certificate tells you the material was measured and how. It does not establish potency, it does not establish suitability for any patient or procedure, and it says nothing about a container opened outside the supplier’s control.
That is the correct division. Judging suitability is a prescriber determination on a named patient, and no document substitutes for it.
How to get the documentation
Every document described on this page is one a supplier can send on request, and the request is routine rather than adversarial. Ask during pricing, when it is a normal part of qualifying a source, and a supplier who holds the package will send it within a business day.
ExaVeyra releases lot-specific certificates, characterisation data and the pharmacy formulary to practices once NPI verification is complete. Verification is what separates a public catalogue from wholesale access, and it is the same step that makes pricing visible.
Sources
- 21 CFR Part 1271, human cells, tissues, and cellular and tissue-based products (accessed 29 August 2026)
- 21 CFR Part 610, General Biological Products Standards (accessed 29 August 2026)
Scientific literature
Each source carries the kind of study it was and, where the study enrolled people, how many. Study design decides what a result can establish, so it is stated rather than left to be inferred. Each line also says what that source is carrying on this page.
- Welsh JA, Goberdhan DCI, O’Driscoll L, et al. Minimal information for studies of extracellular vesicles (MISEV2023): from basic to advanced approaches. Journal of Extracellular Vesicles, 2024. doi:10.1002/jev2.12404 PMID:38326288Consensus statementLandmarkSource 1 supports: The reporting standard a characterisation package is usually assembled against. Cited here for the structural point that completeness of reporting is a separate question from the values reported.