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Research resources
How peptide quality is measured, verified and documented — reading a certificate of analysis, what each laboratory test actually proves, and how to check a supplier against evidence rather than claims. Written as analytical chemistry and quality assurance, with primary sources cited throughout.
5 chapters38 glossary termsLast reviewed 23 July 2026View lab results →
Every purity percentage on a certificate is an area measurement taken from a trace like this one — chapter one covers how to read it.
Reading a COA
What should a certificate of analysis actually show, and how do you verify it?
The fields a COA must contain, how to read the HPLC and mass-spec results, the red flags, and how to verify any batch — including ours — independently.
DefinesBatch (lot) numberCertificate of analysis (COA)ChromatogramImpurity peakMolecular weight
Purity vs peptide content
Why isn't the milligram figure on a vial the amount of peptide you are getting?
Salt form, residual water and excipients mean the powder mass isn't the peptide mass — and purity and net peptide content are two different numbers.
DefinesAcetate saltExcipientGross peptide weightmcg vs mgNet peptide content
Lab testing methods
Which tests prove what about a peptide, and what does each one miss?
HPLC, mass spectrometry, amino acid analysis, water content and endotoxin testing — what each measures, and the limits of each.
DefinesAmino acid analysisEndotoxinHPLCKarl Fischer titrationLAL test
Storage & stability
How should peptides be stored, and how do you spot a compromised vial?
Why material ships lyophilised, storage windows for dry versus reconstituted material, degradation pathways, and the on-arrival checks that matter.
DefinesCold chainDeamidationFreeze–thaw cycleLyophilisationReconstitution
Supplier verification
How do you objectively evaluate a research-peptide supplier?
An objective checklist — batch-specific public certificates, named contactable labs, vial-to-certificate traceability, and honest handling of failed batches.
DefinesResearch use onlyThird-party testing
Every analytical-chemistry and quality-assurance term used across these chapters, each with a plain-language definition and the chapter that covers it in depth.
The whole library is also a single A4 PDF — every chapter and the full glossary, typeset for printing, citing and circulating around a lab. It carries a content ID on each page so you can tell which revision you are quoting.
Nothing is gated behind it. Every word above is on this site, free, and stays that way — the PDF is a convenience, not a paywall.
