[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"article-\u002Farticles\u002Fcoa-verification-checklist":3},{"_path":4,"_dir":5,"_draft":6,"_partial":6,"_locale":7,"title":8,"description":9,"tag":10,"order":11,"readingTime":12,"body":13,"_type":306,"_id":307,"_source":308,"_file":309,"_stem":310,"_extension":311},"\u002Farticles\u002Fcoa-verification-checklist","articles",false,"","Third-party COA verification: a researcher's checklist","What to look for in a Certificate of Analysis when procuring research-grade peptides — and the red flags that indicate a substandard supply chain.","Procurement",2,"5 min read",{"type":14,"children":15,"toc":298},"root",[16,24,29,36,41,117,123,128,192,198,209,214,219,242,248,253,271,276,282,287,293],{"type":17,"tag":18,"props":19,"children":20},"element","p",{},[21],{"type":22,"value":23},"text","A Certificate of Analysis (COA) is the single most important document a researcher receives with a peptide procurement. It's also the document where the difference between a research-grade supplier and a low-quality reseller becomes obvious.",{"type":17,"tag":18,"props":25,"children":26},{},[27],{"type":22,"value":28},"This is a practical checklist. Every researcher building a procurement standard should have something like it.",{"type":17,"tag":30,"props":31,"children":33},"h2",{"id":32},"what-a-real-coa-contains",[34],{"type":22,"value":35},"What a real COA contains",{"type":17,"tag":18,"props":37,"children":38},{},[39],{"type":22,"value":40},"A research-grade COA, issued by an independent analytical laboratory, will include at minimum:",{"type":17,"tag":42,"props":43,"children":44},"ol",{},[45,57,67,77,87,97,107],{"type":17,"tag":46,"props":47,"children":48},"li",{},[49,55],{"type":17,"tag":50,"props":51,"children":52},"strong",{},[53],{"type":22,"value":54},"Lot\u002Fbatch identifier",{"type":22,"value":56}," that matches the lot number printed on the vial received",{"type":17,"tag":46,"props":58,"children":59},{},[60,65],{"type":17,"tag":50,"props":61,"children":62},{},[63],{"type":22,"value":64},"Date of analysis",{"type":22,"value":66},", which should be reasonably recent (within 12 months for stable peptides, sooner for less stable compounds)",{"type":17,"tag":46,"props":68,"children":69},{},[70,75],{"type":17,"tag":50,"props":71,"children":72},{},[73],{"type":22,"value":74},"Identity confirmation",{"type":22,"value":76}," via mass spectrometry showing the expected molecular weight",{"type":17,"tag":46,"props":78,"children":79},{},[80,85],{"type":17,"tag":50,"props":81,"children":82},{},[83],{"type":22,"value":84},"Purity measurement",{"type":22,"value":86}," via HPLC (typically RP-HPLC), reported as a percentage with the chromatogram included or available on request",{"type":17,"tag":46,"props":88,"children":89},{},[90,95],{"type":17,"tag":50,"props":91,"children":92},{},[93],{"type":22,"value":94},"Net peptide content",{"type":22,"value":96},", distinct from mass-of-vial weight",{"type":17,"tag":46,"props":98,"children":99},{},[100,105],{"type":17,"tag":50,"props":101,"children":102},{},[103],{"type":22,"value":104},"Issuing laboratory name, address, and signature",{"type":22,"value":106}," — independent of the seller",{"type":17,"tag":46,"props":108,"children":109},{},[110,115],{"type":17,"tag":50,"props":111,"children":112},{},[113],{"type":22,"value":114},"Method documentation",{"type":22,"value":116}," — at least the column type, mobile phase, and detection wavelength used",{"type":17,"tag":30,"props":118,"children":120},{"id":119},"red-flags",[121],{"type":22,"value":122},"Red flags",{"type":17,"tag":18,"props":124,"children":125},{},[126],{"type":22,"value":127},"A COA that's missing any of the above, or that displays any of the following, should be treated as inadequate:",{"type":17,"tag":129,"props":130,"children":131},"ul",{},[132,142,152,162,172,182],{"type":17,"tag":46,"props":133,"children":134},{},[135,140],{"type":17,"tag":50,"props":136,"children":137},{},[138],{"type":22,"value":139},"Self-issued by the seller",{"type":22,"value":141}," — no independent third-party laboratory listed",{"type":17,"tag":46,"props":143,"children":144},{},[145,150],{"type":17,"tag":50,"props":146,"children":147},{},[148],{"type":22,"value":149},"No lot number",{"type":22,"value":151},", or lot numbers that suggest the same COA is reused across batches",{"type":17,"tag":46,"props":153,"children":154},{},[155,160],{"type":17,"tag":50,"props":156,"children":157},{},[158],{"type":22,"value":159},"Purity reported as \"≥99%\" with no chromatogram",{"type":22,"value":161}," and no method detail. The chromatogram is the evidence; the percentage alone is a claim",{"type":17,"tag":46,"props":163,"children":164},{},[165,170],{"type":17,"tag":50,"props":166,"children":167},{},[168],{"type":22,"value":169},"Stated mass of vial without net peptide content",{"type":22,"value":171}," — common for low-quality sources, where the actual peptide content can be 70–80% of stated weight after counter-ions and water",{"type":17,"tag":46,"props":173,"children":174},{},[175,180],{"type":17,"tag":50,"props":176,"children":177},{},[178],{"type":22,"value":179},"Dates more than 18 months old",{"type":22,"value":181}," for stable peptides, or any age for unstable compounds",{"type":17,"tag":46,"props":183,"children":184},{},[185,190],{"type":17,"tag":50,"props":186,"children":187},{},[188],{"type":22,"value":189},"Identity confirmation missing or implausible",{"type":22,"value":191}," — mass spectrometry data should match published molecular weight to within reasonable tolerance",{"type":17,"tag":30,"props":193,"children":195},{"id":194},"what-to-ask-before-procurement",[196],{"type":22,"value":197},"What to ask before procurement",{"type":17,"tag":18,"props":199,"children":200},{},[201,203],{"type":22,"value":202},"The most useful procurement question is simple: ",{"type":17,"tag":204,"props":205,"children":206},"em",{},[207],{"type":22,"value":208},"\"Can you send me the lot-specific COA, issued by a third-party analytical laboratory, for the specific batch you'll be shipping?\"",{"type":17,"tag":18,"props":210,"children":211},{},[212],{"type":22,"value":213},"A research-grade supplier will produce that document quickly and routinely. A reseller dropshipping unverified product will not.",{"type":17,"tag":18,"props":215,"children":216},{},[217],{"type":22,"value":218},"Two follow-up questions worth asking:",{"type":17,"tag":129,"props":220,"children":221},{},[222,232],{"type":17,"tag":46,"props":223,"children":224},{},[225,230],{"type":17,"tag":204,"props":226,"children":227},{},[228],{"type":22,"value":229},"\"Which third-party lab issued the COA?\"",{"type":22,"value":231}," — should be a recognizable analytical laboratory",{"type":17,"tag":46,"props":233,"children":234},{},[235,240],{"type":17,"tag":204,"props":236,"children":237},{},[238],{"type":22,"value":239},"\"What were the test conditions?\"",{"type":22,"value":241}," — should be a specific HPLC method, not a vague answer",{"type":17,"tag":30,"props":243,"children":245},{"id":244},"independent-labs-commonly-cited-in-research-peptide-coas",[246],{"type":22,"value":247},"Independent labs commonly cited in research peptide COAs",{"type":17,"tag":18,"props":249,"children":250},{},[251],{"type":22,"value":252},"The space of analytical laboratories that issue peptide COAs is small. Researchers procuring research peptides will frequently see COAs from labs like:",{"type":17,"tag":129,"props":254,"children":255},{},[256,261,266],{"type":17,"tag":46,"props":257,"children":258},{},[259],{"type":22,"value":260},"Janoshik Analytical",{"type":17,"tag":46,"props":262,"children":263},{},[264],{"type":22,"value":265},"Freedom Diagnostics",{"type":17,"tag":46,"props":267,"children":268},{},[269],{"type":22,"value":270},"Eurofins (when contracted)",{"type":17,"tag":18,"props":272,"children":273},{},[274],{"type":22,"value":275},"Cross-reference any COA against the issuing lab's website if you have any reason to question authenticity. A real lab will respond to direct verification requests for lots they've tested.",{"type":17,"tag":30,"props":277,"children":279},{"id":278},"storing-coas-alongside-experimental-records",[280],{"type":22,"value":281},"Storing COAs alongside experimental records",{"type":17,"tag":18,"props":283,"children":284},{},[285],{"type":22,"value":286},"For reproducibility, the COA for the specific lot used in any experiment should be retained alongside the experimental records. If you're publishing or building toward publication, lot-level documentation is the standard. Researchers who treat COAs as throwaway documents tend to discover, the hard way, that they can't reproduce their own results when they switch lot numbers.",{"type":17,"tag":30,"props":288,"children":290},{"id":289},"want-the-full-procurement-quality-checklist",[291],{"type":22,"value":292},"Want the full procurement quality checklist?",{"type":17,"tag":18,"props":294,"children":295},{},[296],{"type":22,"value":297},"Our researcher resource pack includes a printable COA checklist, a sample COA with annotations on what each section means, and current notes on which third-party labs are issuing reliable peptide analytical work. Drop your email below if you'd like it.",{"title":7,"searchDepth":11,"depth":11,"links":299},[300,301,302,303,304,305],{"id":32,"depth":11,"text":35},{"id":119,"depth":11,"text":122},{"id":194,"depth":11,"text":197},{"id":244,"depth":11,"text":247},{"id":278,"depth":11,"text":281},{"id":289,"depth":11,"text":292},"markdown","content:articles:2.coa-verification-checklist.md","content","articles\u002F2.coa-verification-checklist.md","articles\u002F2.coa-verification-checklist","md"]