What is a peptide Certificate of Analysis (CoA)?

A peptide Certificate of Analysis (CoA) is a document from an independent analytical laboratory confirming the identity and purity of a specific batch of research compound. A legitimate CoA includes HPLC purity percentage, mass spectrometry identity confirmation, batch number, test date, and the testing laboratory's name. Purity above 98% is considered high quality for research use.

What is a good purity score on a peptide CoA?

98% or above is the standard benchmark for research-grade peptides. 95-97% is acceptable for most applications. Below 95% indicates significant impurities and should be avoided. The purity figure on an HPLC CoA represents the percentage of the target compound relative to all UV-absorbing species in the sample.

How do I spot a fake peptide CoA?

Red flags for a fake CoA: no batch number, batch number does not match the vial label, generic lab name with no verifiable address or accreditation, missing mass spectrometry data (identity confirmation), suspiciously round purity figures (exactly 99.00%), no test date, or a PDF that appears to be a template reused across compounds. Cross-reference the batch number against a third-party database like ASCEND CoA to confirm the result exists independently.

What is the difference between HPLC and mass spectrometry on a CoA?

HPLC (High-Performance Liquid Chromatography) measures purity by separating compounds and quantifying the target peak as a percentage of the total. Mass spectrometry (MS) confirms identity by measuring the molecular weight of the compound and matching it to the expected value. A complete CoA should include both: HPLC for purity and MS for identity. A CoA with only HPLC and no MS cannot confirm you have the correct compound.

How do I use the ASCEND CoA database?

Search by peptide name, batch number, or seller at ascendpeptide.org/coa/. The database contains 500+ community-submitted and verified Certificates of Analysis. Match your vial's batch number to confirm the CoA shown by your seller matches an independently recorded result. You can also submit your own lab results to add to the database.

FAQ

Peptide Certificate of Analysis (CoA)

A Certificate of Analysis is the primary document verifying that a peptide batch meets purity and identity standards. Understanding how to read one, and how to verify it is genuine, is essential before using any research compound.

TL;DR - A legitimate CoA includes HPLC purity (98%+ is good), mass spectrometry identity confirmation, a specific batch number, and an identifiable testing laboratory. Search the ASCEND CoA database to cross-check any batch number against independently recorded results.

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What a CoA must contain

HPLC purity percentage - The target compound as a percentage of all UV-absorbing species. 98%+ is research-grade. Below 95% is problematic.

Mass spectrometry (MS) identity - Confirms the molecular weight matches the expected compound. Without MS, you cannot verify you have the correct peptide.

Batch or lot number - Must match the number on your vial. A CoA without a batch number cannot be tied to a specific production run.

Testing laboratory name and date - The lab should be identifiable and separate from the seller. The test date should precede your purchase.

Purity score reference

HPLC Purity	Grade	Notes
99%+	Excellent	Pharmaceutical-grade standard
98-99%	Research-grade	Standard for quality suppliers
95-97%	Acceptable	Marginal, check for MS confirmation
Below 95%	Avoid	Significant impurities present

How to spot a fake CoA

Fraudulent CoAs are common in the research peptide market. The most reliable method is cross-referencing your batch number against an independent database.

Red flags: No batch number. Batch number does not match your vial. Missing mass spectrometry data. Suspiciously round purity (exactly 99.00%). Generic lab name with no address or accreditation. Same PDF template reused across different compounds with only the name changed.

Verification step: Search your batch number in the ASCEND CoA database. If the result appears there independently, it means a third party recorded the same data, which is a strong signal of legitimacy.

HPLC vs mass spectrometry

HPLC measures purity by separating the sample and quantifying the target peak as a percentage of the total. It tells you how pure the sample is, but not what it is.

Mass spectrometry measures the molecular weight of the compound and confirms identity by matching it to the expected value for the stated peptide. It tells you what the compound is, but not the purity percentage.

A complete CoA includes both. HPLC without MS means you know it is pure, but not that it is the correct compound. MS without HPLC means you know the identity, but not how much of the sample is actually that compound.

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Research References

Wang W. - Instability, stabilization of liquid protein pharmaceuticals
Int J Pharm 1999 · PMID 10502313 · Analytical standards basis

ASCEND is a mathematical reference tool for research purposes only. Not for medical use.
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