How to Read a Lot-Specific Certificate of Analysis

909 Aminos LLC · Published 19 October 2026 · Updated 24 October 2026

A certificate of analysis (COA) is a laboratory's record of the tests it ran on a sample from one specific lot, listing each result with the method used and the limit it was judged against.

A certificate of analysis (COA) is a laboratory's record of the tests it ran on a sample from one specific lot. This page goes through a certificate field by field, using a real 909 lot as the example, and explains what each result does and does not tell you.

A certificate describes one lot, not a product

Every certificate 909 publishes is tied to one product code and one lot number. A result reported for lot TESA-2609A describes the sample the laboratory received and tested, which 909 submitted as lot TESA-2609A. It does not describe other lots of the same product, other strengths or other products. That's why 909 publishes testing by lot: each tested lot has its own page at 909aminos.com/coa/<LOT>, and the Documentation Center lists the tested lots under each product.

The fields, in order

Worked example: lot TESA-2609A

As stated on the laboratory's certificate:

The certificate states that its specification set is client / method-defined. The acceptance limits were set for this testing; they are not a pharmacopeial monograph.

Identity: "Identity Conforms (RT + UV vs. reference)"

The sample was compared with a reference on two properties:

• RT (retention time): when the compound comes off the HPLC column. For this lot, the main peak eluted at 9.249 minutes.
• UV: the shape of its ultraviolet absorbance spectrum, recorded by the diode-array detector (DAD).

"Conforms" means both matched the reference within the laboratory's criteria.

Purity: "99.22% (area %)"

• HPLC separates the components of the sample. Purity by area % is the main peak's share of the total integrated peak area that the method detected.
• It describes how much of the detected material is the target compound, compared with the impurities detected.
• It is not a measure of how much material is in the vial. The certificate says so itself: purity does not measure what fraction of the powder is peptide rather than counter-ion, water or residual solvent.

Content per vial: "10.28 mg (102.8% of label claim)"

• This is a separate measurement. The certificate reports it as mg of net peptide per vial, compared with the 10 mg on the label.
• 102.8% means the measured amount was slightly above the label quantity, and within the stated specification of at least 90%.
• Purity and content answer different questions, so a certificate should report both.

What a certificate does not tell you

• It doesn't cover any lot other than the one named. This certificate says its results apply only to the sample submitted.
• It reports only the tests listed. This certificate states that, unless noted, no assessment was made of sterility, endotoxin, microbial, heavy-metal or residual-solvent content.
• Information the client supplies (label claim, lot number and sample identity) is reported as provided. The laboratory does not independently verify it.
• It is not a determination of safety, quality or fitness for any purpose, and it does not make a product approved for any use. The certificate states this itself.

How to check a certificate

1. Match the lot. The lot on the certificate equals the lot on your vial.
2. Check the laboratory and certificate number. The issuing laboratory is named, and the certificate number is shown.
3. Open the original. 909's lot pages link to the laboratory's own certificate file.
4. Use the laboratory's verification. KMD Analytical certificates carry a QR code and point to the laboratory's verification page (kmdanalytical.com/verify), so the document can be checked independently of 909.

Independent and supplier documentation

909 publishes a certificate as independent testing only when 909 commissioned the testing from an independent laboratory and the original report is on file. Analytical documentation that comes with material from a supplier is different. Where it is mentioned, it is identified as supplier documentation held on file. It is never presented as 909's independent testing or as a lot result. Products without a published certificate are shown as such in the Documentation Center.

Frequently asked questions

Does a certificate of analysis cover every lot of a product?

No. It describes the sample tested from the lot named on the certificate. Another lot of the same product needs its own certificate.

What does a "client / method-defined" specification mean?

The acceptance limits were set for this testing by the client and the laboratory method, not taken from a pharmacopeial monograph. Read each result against the limit printed beside it.

Which tests are not covered by this certificate?

Only the tests it lists. The TESA-2609A certificate states that, unless noted, no assessment was made of sterility, endotoxin, microbial, heavy-metal or residual-solvent content.

Does a certificate show that a material is safe or approved?

No. A certificate reports analytical findings on the submitted sample. It is not a determination of safety, quality or fitness for any purpose, and it does not make a product approved for any use.

Sources

• KMD Analytical certificate 9AL-20260921-C7PG-01 (lot TESA-2609A), original PDF
• 909 Aminos lot page for TESA-2609A
• KMD Analytical: certificate verification service
• KMD Analytical: scope of services and limitations

Sources are cited for reference. Their publishers have not reviewed or endorsed this guide.

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For laboratory research use only. Not for human or veterinary use. Not FDA approved.

Source certificate: lot TESA-2609A · Documentation Center · Ver en español