How to Read a Certificate of Analysis (COA)

What is a Certificate of Analysis?

A Certificate of Analysis (COA) is a document issued by an analytical laboratory that reports the results of testing performed on a specific batch of a compound. For research peptides, a COA serves as the primary verification that what is labeled on the product matches what is actually in the vial. It provides objective, third-party evidence of compound identity, purity, and quality — the three pillars of reliable research materials. Without a COA, researchers have no independent way to verify the integrity of their materials, which can compromise experimental validity and reproducibility.

Why COAs Matter for Research

In peptide research, even small impurities or incorrect compound identities can invalidate results. A COA from a reputable independent laboratory gives researchers confidence that their experimental variables are controlled at the material level. This is particularly important when comparing results across different batches, time periods, or research groups. The COA creates a chain of accountability from manufacturer to researcher, and its absence should be considered a significant concern when evaluating any peptide supplier.

HPLC (High-Performance Liquid Chromatography)

HPLC is the gold standard for peptide purity analysis. This technique separates a sample into its individual components based on their chemical properties, then quantifies each component's relative abundance. On a COA, the HPLC result is reported as a purity percentage — for example, 99.2%. This number represents the proportion of the sample that consists of the target peptide versus impurities (truncated sequences, deletion products, oxidized forms, etc.). For research-grade peptides, a purity of >99% indicates that less than 1% of the sample consists of non-target compounds. The chromatogram itself (the graph showing peaks) should display a single dominant peak with minimal secondary peaks.

Mass Spectrometry (MS)

While HPLC tells you how pure a sample is, mass spectrometry confirms what the sample actually is. MS measures the molecular weight of compounds in the sample with high precision. The observed molecular weight is compared to the expected (theoretical) molecular weight of the target peptide. A match confirms compound identity. On a COA, you should see both the expected MW and the observed MW, with the observed value falling within an acceptable range (typically within 1 Da of the expected value). If these numbers do not match, it indicates the sample may contain the wrong compound entirely — regardless of what the HPLC purity says.

Endotoxin Testing

Endotoxin testing measures the presence of bacterial lipopolysaccharides (LPS) — toxic components of gram-negative bacterial cell walls that can contaminate peptide preparations during manufacturing. Endotoxin contamination is particularly relevant for in vitro cell culture research, as even trace levels of LPS can activate immune cells and confound experimental results. The standard test (Limulus Amebocyte Lysate, or LAL) reports results in Endotoxin Units per milligram (EU/mg). Research-grade peptides should demonstrate low endotoxin levels to ensure they are suitable for sensitive biological assays.

What to Look For on a COA

A trustworthy COA should include several key elements. First, the name and contact information of the independent testing laboratory — for EIDON Research products, this is Janoshik Analytical, a globally recognized facility specializing in compound verification. Second, a unique batch number that ties the test results to a specific production run. Third, the date of analysis, confirming when the testing was performed. Fourth, the complete test results including HPLC purity percentage, mass spectrometry molecular weight confirmation, and any additional tests performed. The COA should clearly identify both the compound tested and the analytical methods used.

Red Flags to Watch For

Several indicators can suggest a COA may not be reliable. The absence of a named testing laboratory is a major concern — legitimate COAs always identify the lab. Missing batch numbers make it impossible to trace results to specific products. Suspiciously round purity numbers (exactly 99.0% or 100.0%) are unusual in real analytical chemistry, where results naturally include decimal variation. COAs that lack chromatograms or raw data may be fabricated. Inconsistencies between the listed compound and the molecular weight data indicate either testing errors or misrepresentation. Finally, be wary of COAs that appear to use the same template across many different suppliers, as these may be generic or recycled documents rather than genuine test reports.

EIDON Research Quality Standards

Every batch of EIDON Research peptides is tested at Janoshik Analytical, an independent laboratory with no affiliation to EIDON. All products are guaranteed to meet or exceed >99% purity as verified by HPLC. COAs are available for every batch upon request and include complete analytical data with batch traceability.