How to read a MOTS-c certificate of analysis

A certificate of analysis (COA) is the laboratory's report on one sample. A useful one ties specific results to a specific lot, names the methods, dates the work and shows the raw evidence. This guide walks through each section of a MOTS-c certificate using the current lot as the example, then sets out what a COA establishes and what it does not.

The current MOTS-c lot, as an example

Lot number

The lot number identifies the batch the sample came from, for example KB-44745. It must match the lot printed on your vial label; a certificate for a different lot tells you nothing about your vial. Each MOTS-c lot has its own page in the COA archive, and any lot can be looked up at buymotscpeptide.com/verify.

Laboratory and reference numbers

• Testing laboratory: who performed the analysis. MOTS-c certificates are issued by ILS Laboratories, an independent laboratory.
• Client: who submitted the sample. Current certificates list Klow.bio / Klow Labs LLC, the company that operates MOTS-c Research Supply.
• Accession number and search code: the laboratory's own identifiers for the sample, used to look the result up with the lab.

To verify a MOTS-c certificate with the laboratory: Go to portal.ils-lab.com (or scan the QR code on the certificate) and enter the lot’s verification access code, listed on its lot page, to view the laboratory’s own copy of the certificate.

Testing dates

A certificate carries two dates: when the laboratory received the sample and when it reported the results. The results describe the sample as it was when tested. For a lyophilized peptide stored correctly, change over months is typically slow, but a certificate is not a measurement of the material on any later date.

Sample summary

A one-glance version of the results: product, purity, identity, net content and appearance, plus endotoxin and microbial results where those tests were run. Treat it as a summary; the detail is below it.

HPLC purity

Reported as a percentage by HPLC-UV. Check that the chromatogram is included and that the labeled main peak matches the product. A purity figure without a chromatogram cannot be checked. See HPLC analysis of MOTS-c.

Identity

Reported as confirmed or not, with the method named. Common methods are LC-MS, which measures the main component's mass, and HPLC retention-time comparison with a reference standard. With LC-MS, labeled ions should match values calculated from the compound's molecular weight.³ MOTS-c certificates use HPLC retention-time comparison with a reference standard (HPLC-RTM).

Net content

The measured milligrams of peptide in the tested vial. It is a different measurement from purity. See net content.

Endotoxin and microbial testing

Where run, endotoxin is reported by Limulus amebocyte lysate assay per USP <85> as pass or fail at a stated sensitivity, and microbial DNA by PCR.² On MOTS-c Research Supply lot pages, lots without these tests are marked "Not tested" rather than left blank.

Signature and disclaimer

The certificate is signed by the laboratory's principal chemist. The disclaimer states that results apply only to the tested sample and that sample handling can affect accuracy.

The certificate PDF and the lot record

For each MOTS-c lot, MOTS-c Research Supply publishes two things: the laboratory's certificate as a PDF, and a lot record page on buymotscpeptide.com. The PDF is the laboratory's own document, including the chromatogram and the QR code for verification. The lot record reproduces every figure as readable text and adds the laboratory's reference numbers. The two should match exactly; if they ever don't, the laboratory's document is the authoritative one.

Reading the chromatogram yourself

• Find the labeled main peak and check that its label matches the product.
• Look at the baseline. It should be flat and low, with no large unlabeled peaks.
• Note early signals near the start of the run. These usually elute close to the column's void time and are typically small polar species, not related peptides.
• Check that the purity figure is plausible for what you see. A chromatogram with several large peaks cannot support a 99% purity figure.

Comparing certificates across lots

Lot-to-lot comparison is useful when the same laboratory and methods are used. For MOTS-c, all current certificates come from the same laboratory using the same HPLC and HPLC-RTM methods, so results can be compared directly. Look for consistent retention time and purity within the stated specification. Some lots carry additional tests, such as endotoxin and PCR, and others do not; a missing test is not a failed test, but it is also not a pass.

Red flags on any certificate

• No lot number, or a lot number that doesn't match the vial.
• No laboratory name or contact details.
• A purity figure with no chromatogram.
• Identity reported with no method named.
• No dates, or dates that predate the material's production.
• The same certificate used for several products or lots.
• No way to confirm the result with the laboratory.

Common misreadings

• "99.9% purity means 99.9% of the powder is peptide." No. Purity is relative to UV-detected material; water, salts and counterions are not counted. See peptide purity.
• "Identity confirmed means the sequence was verified." Mass confirmation verifies molecular weight. Sequence order needs additional methods.
• "A pass on endotoxin applies to the product." It applies to the lot and sample tested.
• "The certificate shows the material today." It shows the sample on its test date.

What a COA establishes

• That a specific sample, from a named lot, was tested by a named laboratory on stated dates.
• The purity of that sample under the stated HPLC method.
• That the main component's mass matches the expected compound.
• The measured amount of peptide in the tested vial.
• Endotoxin and microbial results, where those tests are listed.

What a COA does not establish

• Results for any other lot.
• Sequence order (mass confirmation alone cannot distinguish rearranged sequences).
• Stability after the test date.
• Results for tests that are not listed on it.
• Suitability for any particular purpose.

Checklist for any peptide COA

1. Does the lot number on the certificate match the lot on the vial?
2. Is the testing laboratory named, with contact details you can check independently?
3. Are the methods named for each result?
4. Is the chromatogram included, not just a purity number?
5. Is a mass spectrum included, and do the labeled ions match the compound's molecular weight?
6. Are the received and reported dates shown?
7. Is it clear which tests were not performed?
8. Can the result be confirmed with the laboratory directly?

Validation of the underlying methods is outside what a single certificate can show; ICH Q2(R2) describes what a validated method should demonstrate.¹