A researcher's 7-point checklist for verifying HPLC purity, mass-spec identity, and batch documentation.
A Certificate of Analysis (COA) is the single most useful document for evaluating a research peptide. It's the lab report that tells you what's actually in the vial. Learning to read one is the difference between buying on trust and buying on evidence. Here's the 7-point checklist we use, and that any researcher should apply before purchasing.
A real COA is tied to a specific production lot — not the product in general. The lot number on the document should match the lot number printed on the vial you receive. A single generic, undated COA reused across every order is the most common red flag in this industry. Every Midas batch is lot-numbered and matched to its own certificate in our COA library.
Mass spec confirms the molecular weight of the compound matches the expected target. It answers the most basic question: is this actually the peptide on the label? Without an identity test, purity numbers are meaningless — you could have a very pure sample of the wrong molecule.
High-Performance Liquid Chromatography separates the sample into its components and reports the target peptide as a percentage of the whole. Look for a figure like ≥98–99%. Crucially, that number should be backed by an actual chromatogram — the graph — not just a value typed onto a page.
One clean, dominant peak indicates a high-purity sample. A cluster of smaller peaks alongside it indicates impurities or by-products. Reputable suppliers publish the graph so you can see the peak with your own eyes rather than taking a summary number on faith.
Recent testing by a named, accredited, independent lab carries far more weight than an undated certificate from an unnamed source. A supplier grading its own product has an obvious conflict of interest; third-party testing removes it.
Many COAs also report residual solvent or water content and a visual/appearance check. Lyophilized (freeze-dried) peptides should be described consistently with what you receive. Large discrepancies are worth questioning.
The strongest signal of all: the COA is public and matched to your lot before you buy — not something you have to email for after the fact. Transparency up front is the whole point.
In controlled research, impurities are variables you didn't intend to introduce. A sample that's 80% target compound and 20% unknown by-products makes results harder to interpret and reproduce. Verified purity narrows that uncertainty — a methodological argument, not a health one. Cleaner inputs make for cleaner data.
If a supplier can't show you a batch-specific, third-party COA with a chromatogram, you're buying on trust. Documentation is the only version of "premium" that means anything.
Every compound in the Midas catalog ships with a batch-matched third-party COA covering identity and HPLC purity. Want the full reference, including reconstitution and storage guidance? Download the free MIDAS Research Guide.
View our COA library → Browse the catalog →