The CAS number (Chemical Abstracts Service Registry Number) is a unique numerical identifier assigned to every chemical substance documented in the CAS registry, a division of the American Chemical Society founded in 1907. This number unambiguously identifies a molecule across global scientific, regulatory and commercial databases, regardless of its many trade names, IUPAC nomenclatures or synonyms.
CAS number structure: three blocks of digits separated by hyphens, format XXXXXXX-XX-X. The first block can reach seven digits, the second is always two, the third is an algorithm-calculated check digit. Over 270 million substances are currently listed, with 15,000 new registrations daily.
For a research peptide, the CAS number fulfills several practical functions. International traceability: it enables finding the same molecule in Sigma-Aldrich, Tocris, Bachem, Anaspec catalogs or PubMed publications. Regulatory compliance: it is required on safety data sheets (SDS/MSDS), customs declarations, European REACH declarations, import forms. Bibliographic research: most scientific articles index studied compounds by CAS number in appendices.
Some examples of frequent peptide CAS numbers: BPC-157 (137525-51-0), TB-500 fragment (77591-33-4), semaglutide (910463-68-2), tirzepatide (2023788-19-2), liraglutide (204656-20-2), ipamorelin (170851-70-4). Verifying the CAS number on COA and invoice is a quality control reflex enabling detection of labeling errors, form confusions (free vs salt, fragment vs full form) and commercial diversions.
Caveat: not all experimental peptides necessarily have a CAS number (notably very recent analogs or in-house synthesis products from suppliers). CAS absence is not systematically disqualifying, but a serious supplier must justify this absence and provide an alternative reference (internal number, detailed chemical structure, theoretical molecular mass).
Décryptez la caractérisation complète d'un peptide : RP-HPLC préparative et analytique, LC-MS haute résolution Orbitrap/QTOF, RMN 2D (COSY/TOCSY/NOESY), dégradation d'Edman, cartographie peptidique MS/MS, dichroïsme circulaire. Les 10 techniques qui séparent un peptide research-grade d'un peptide douteux, avec seuils de détection et stratégie de QC.
Maitrisez les mecanismes qui detruisent vos peptides : oxydation Met, deamidation Asn, hydrolyse, aggregation. Protocoles de lyophilisation, conditions de stockage, reconstitution optimale et QC shelf-life. Le pilier technique que tout laboratoire doit integrer pour garantir l'integrite de ses peptides en recherche exploratoire.
Principe Merrifield, stratégies Fmoc et Boc, résines (Wang, Rink amide, 2-chlorotrityl), agents de couplage (HBTU, HATU, DIC/HOBt), cycle de synthèse, clivage TFA, purification RP-HPLC, contrôle qualité LC-MS et test Kaiser. Le pilier scientifique de référence sur la fabrication des peptides synthétiques.