909 AMINOSHow to Verify a Certificate of Analysis
Verifying a certificate of analysis means confirming three separate things: that the laboratory issued it, that the file has not been altered, and that it names the lot you have.
- Look up the certificate number on the laboratory's own website. Type the address yourself.
- If the laboratory offers PDF verification, use it to check whether your file matches the laboratory's issued record. This does not verify the vial itself.
- Match the lot on the certificate to the lot on your vial.
- A lookup can't show which vials came from that lot.
A certificate of analysis is a claim made by a laboratory. Before relying on it, it's reasonable to check three things: that the laboratory really issued it, that the file hasn't been changed since, and that it names the lot you actually have. None of these checks needs special equipment, and they work on any supplier's certificate. Each one answers a different question, and no single check answers all three.
1. Find the issuer and the certificate ID
A genuine certificate names the issuing laboratory and carries the laboratory's own certificate number. That number is different from the supplier's lot number. Many certificates also list the laboratory's internal batch or sample ID and the dates the sample was received and analyzed. A document with no laboratory name or no certificate number can't be checked with anyone, which is a reason for caution in itself.
2. Confirm it with the laboratory, on the laboratory's own website
Many independent laboratories run a lookup where you enter the certificate ID, or scan the QR code printed on the certificate, and the laboratory confirms whether it issued that certificate.
- Reach the lookup independently. Type the laboratory's address yourself or find it through a search. Don't rely only on a link supplied with the document. A verification page proves something only if it's on the laboratory's real domain, and lookalike domains exist.
- Compare whatever details the lookup returns with the document in front of you, not just the "verified" message.
- Know what the lookup covers. A lookup confirms what that laboratory's service says it confirms, typically that it issued a certificate with that ID. Read the service's own description rather than assuming more.
- If there's no online lookup, email the laboratory at an address taken from its own website and ask it to confirm the certificate number.
3. Check that the file hasn't been altered
A certificate can be genuine and still be edited after it was issued, for example a changed lot number or result. Some laboratories record a cryptographic fingerprint (a hash such as SHA-256) of each certificate file they issue, and offer to compare your copy with it. Where that check is offered and matches, it indicates your file is the one the laboratory recorded. Any edit to a file, however small, changes its fingerprint. A lookup by certificate ID alone doesn't check the file you hold.
Where no file check is offered, compare the key figures with the laboratory directly.
4. Match the certificate to your lot
Authenticity proves the laboratory tested a sample. It doesn't prove the sample came from your vial's lot.
- The client lot on the certificate should match the lot printed on your vial, character for character.
- Laboratories generally record the client's lot number as provided, without verifying it independently. The link between your vial and the tested sample comes from the supplier's lot records and labeling. See From vial to report: lot traceability.
5. Check that the document is internally consistent
- Arithmetic. Percentages of label claim should follow from the numbers: 10.28 mg measured against a 10 mg label claim is 102.8%.
- Results against specifications. Each result should sit next to the limit it was judged against, and the pass/fail status should agree with the two.
- Methods named. Every result should say which technique produced it.
- Whole document. Certificates are usually meant to be reproduced only in full. A cropped image or a retyped summary hides context such as the limitations section.
Warning signs
- No laboratory name, certificate number or test date.
- The same certificate shown for different lots, sizes or products.
- A lot number that doesn't match the vial, or no lot number at all.
- Results with no method or no specification.
- A "verification" link on a domain that isn't the laboratory's.
- A screenshot or summary offered instead of the original file.
None of these proves a certificate is false, but each one means it can't be relied on until it's resolved.
Example: lot TESA-2609A
| Check | Where to find it |
|---|---|
| Issuer and certificate ID | KMD Analytical, certificate 9AL-20260921-C7PG-01, on the certificate and on 909aminos.com/coa/TESA-2609A |
| Laboratory lookup | kmdanalytical.com/verify, typed directly. KMD describes the lookup as confirming whether a certificate ID was issued by the laboratory, and states that this is its only domain |
| File check | KMD describes an optional step: uploading the PDF to compare it with the fingerprint recorded when the certificate was issued |
| Lot match | Client lot TESA-2609A on the certificate, the lot page and the vial label. The lookup doesn't confirm which vials belong to the lot |
| Arithmetic | 10.28 mg against a 10 mg label claim = 102.8%, as reported |
| Original document | Linked from the lot page as the laboratory's own file |
For what the results themselves mean, see How to read a peptide certificate of analysis, and for what an identity result does and doesn't establish, see Identity testing.
What verification doesn't tell you
A successful lookup shows only what the laboratory's service confirms: that it issued a certificate with that ID and, where a file check is offered and used, that your copy matches the file it recorded. It doesn't show that a particular vial came from the named lot, because laboratories record the client's lot number as provided. That link rests on the supplier's lot records and labeling. Verification doesn't add tests the certificate didn't run, doesn't make a result apply to other lots, and, like the certificate itself, isn't a determination of safety or fitness for any purpose.
Frequently asked questions
How do I confirm that a laboratory issued a certificate?
Look up the certificate number on the laboratory's own website, reaching it by typing the address yourself rather than following a link supplied with the document. If there is no online lookup, email the laboratory at an address taken from its website.
What does a laboratory's PDF file check confirm?
Where it is offered and matches, it indicates that your file is byte-for-byte the file the laboratory recorded. It does not verify the vial itself or show that the results apply to other lots.
How can I check a laboratory's accreditation?
If a certificate claims accreditation, for example to ISO/IEC 17025, confirm it with the accreditation body named on it. ILAC lists the accreditation bodies that are signatories to its Mutual Recognition Arrangement. Accreditation covers the specific tests in a laboratory's accredited scope.
Does a verified certificate mean a material is safe or FDA approved?
No. Verification shows that a laboratory issued the certificate and, where a file check is used, that the copy is unaltered. It is not a determination of safety, sterility or approval for any use.
Sources
- KMD Analytical: certificate verification service
- NIST FIPS 180-4, Secure Hash Standard (specifies SHA-256)
- ISO/IEC 17025:2017, General requirements for the competence of testing and calibration laboratories
- ILAC Mutual Recognition Arrangement (accreditation bodies)
- 909 Aminos lot page for TESA-2609A
Sources are cited for reference. Their publishers have not reviewed or endorsed this guide.
Related guides
- From Vial to Report: Lot Traceability
- Identity Testing: Retention Time and UV vs. Mass Spectrometry
- How to Read a Peptide Certificate of Analysis (COA)
For laboratory research use only. Not for human or veterinary use. Not FDA approved.
Source certificate: lot TESA-2609A · Documentation Center · Ver en español