{"product_id":"ponceau-s-acid-red-112-cas-6226-79-5","title":"Ponceau S (Acid Red 112) | CAS 6226-79-5 | BS Grade","description":"\u003cdiv style=\"margin-bottom: 28px;\"\u003e\n\u003cdiv style=\"background: #002147; padding: 10px 20px; margin-bottom: 0;\"\u003e  \u003ch3 style=\"margin: 0; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 0.70em; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; color: #fff;\"\u003eTechnical Specifications\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; font-size: 0.95em; border: 1px solid #e4e8f0; border-top: none; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;\"\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eCAS Number\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003e6226-79-5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eEC \/ EINECS Number\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003e228-319-2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eMDL Number\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003eMFCD00003892\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eRTECS Number\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003eQJ6600000\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eSMILES\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0; word-break: break-all;\"\u003eC1=CC(=CC=C1N=NC2=CC(=C(C=C2)N=NC3=C4C=CC(=CC4=CC(=C3O)S(=O)(=O)[O-])S(=O)(=O)[O-])S(=O)(=O)[O-])S(=O)(=O)[O-].[Na+].[Na+].[Na+].[Na+]\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eInChI\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0; word-break: break-all;\"\u003eInChI=1S\/C22H16N4O13S4.4Na\/c27-22-20(43(37,38)39)10-12-9-16(41(31,32)33)6-7-17(12)21(22)26-25-18-8-3-14(11-19(18)42(34,35)36)24-23-13-1-4-15(5-2-13)40(28,29)30;;;;\/h1-11,27H,(H,28,29,30)(H,31,32,33)(H,34,35,36)(H,37,38,39);;;;\/q;4*+1\/p-4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eInChIKey\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0; word-break: break-all;\"\u003eKQHKSGRIBYJYFX-UHFFFAOYSA-J\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003ePubChem CID\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003e2723873\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eMolecular Formula\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003eC₂₂H₁₂N₄Na₄O₁₃S₄\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eMolecular Weight\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003e760.57 g\/mol\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eMelting Point\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003e\u0026gt;300 °C (dec.)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eSolubility\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003eSoluble in water (~1 mg\/mL); practically insoluble in organic solvents\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003ePurity\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003eDye content: ≥ 85%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003ePhysical Form\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003eRed to reddish-brown powder\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eHS Code\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003e3204.12\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eCountry of Origin\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003eFinland\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eShelf Life\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003eRetest period: 36 months from date of manufacture\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eStorage Conditions\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003eStore at room temperature in a tightly sealed container under inert atmosphere\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003c\/div\u003e\u003cdiv style=\"margin-bottom: 28px;\"\u003e\n\u003cdiv style=\"background: #002147; padding: 10px 20px; margin-bottom: 0;\"\u003e  \u003ch3 style=\"margin: 0; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 0.70em; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; color: #fff;\"\u003eProduct Description \u0026amp; Scientific Applications\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"padding: 16px 20px; border: 1px solid #e4e8f0; border-top: none; font-family: Georgia, 'Times New Roman', serif; font-size: 0.95em; line-height: 1.65; color: #333;\"\u003e\n\u003cp\u003e\u003cstrong\u003ePonceau S\u003c\/strong\u003e (Acid Red 112; C.I. 27195) is a tetrasodium tetra-sulfonated disazo dye, the most commonly used reversible total-protein stain on nitrocellulose and PVDF membranes after Western transfer. It binds non-covalently and rinses free for downstream blocking and antibody detection.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eReversible Total-Protein Detection on Membranes and Gels.\u003c\/strong\u003e Immediately after SDS-PAGE Western transfer, Ponceau S gives a rapid read of transfer efficiency, lane loading, molecular-weight ladder position, and transfer uniformity before blocking. A typical working stain is 0.1% (w\/v) in 1–5% acetic acid; pink-red bands develop in 1–5 minutes and are removed by water or TBS rinses. Positively charged nylon membranes retain the anionic dye too strongly for clean destaining and are not used with Ponceau S. It is also catalogued for staining proteins on cellulose-acetate membranes and electrophoresis gels, read visually or by densitometry.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTotal-Protein Normalisation in Quantitative Immunoblotting.\u003c\/strong\u003e Ponceau S is used for whole-lane total-protein normalisation in quantitative Western blotting, correcting per lane for unequal loading, sample-preparation variation, and transfer differences. Unlike single-housekeeping-protein normalisation, it tolerates conditions where housekeeping proteins themselves vary with treatment, model, or tissue type — a documented limitation of β-actin, GAPDH, and α-tubulin. Detection sensitivity is largely insensitive to dye concentration across roughly 0.001–2% (w\/v) and to acid type (acetic, sulfosalicylic, or trichloroacetic), so a simple 0.01% formulation in 1% acetic acid can match more concentrated ones. Fluorescence imaging under 488 nm excitation improves linearity, sensitivity, and repeatability for conventional and challenging samples.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDisazo Chromophore, Visible-Region Spectroscopy, and Protein Binding.\u003c\/strong\u003e Structurally, Ponceau S is a naphthol-based disazo dye carrying two −N=N− bridges that conjugate a 4-sulfonatophenyl ring through a sulfonated phenyl linker into a 3-hydroxy-naphthalene-2,7-disulfonate core, isolated as the tetrasodium salt. The extended π-conjugation across the two azo bridges and three aromatic rings gives the visible absorption maximum near 519–520 nm in dilute aqueous acid, and the four sulfonate groups confer high water solubility and strong anionic character. Electrophoresis-grade material is commonly specified by a 1% (w\/v) absorbance A1cm1% ≥ 460 at 519.4 nm, convenient for Beer–Lambert quantification and visible-region dye assays. Protein binding is generally attributed to electrostatic ion pairing between sulfonate anions and protonated basic residues, especially the guanidinium and ammonium groups of arginine and lysine, supplemented by non-covalent contacts with less polar regions; binding is pH-dependent, favoured under acidic staining conditions and disrupted by water, buffer, or alkaline rinses, the basis of the reversible destaining.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHistology, Plant Tissue, and Catalogue Distinctions.\u003c\/strong\u003e In histology and microscopy, Ponceau S is catalogued as an acidic protein stain. In plant biology it is a permanent visible-light stain for callose (β-1,3-glucan) deposits in fixed plant tissue, preferred when bright-field imaging or archival permanence is wanted over fluorescence-based aniline blue methods. It is not interchangeable with Ponceau 2R (also Xylidine ponceau; Acid Red 26; C.I. 16150; CAS 3761-53-3), a smaller mono-azo disodium dye used as the red counterstain in classical Masson's trichrome; order Ponceau S (CAS 6226-79-5) and Ponceau 2R separately by CAS.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eOther Applications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eModel anionic disazo dye in studies of dye–protein interactions and reversible non-covalent staining\u003c\/li\u003e\n\u003cli\u003eModel substrate in photocatalytic and advanced oxidation degradation studies, including ZnO photocatalysis, Fe₂O₃\/WO₃ solar photocatalysis, photo-Fenton\/electro-Fenton, Co²⁺\/H₂O₂\/UV, and UV\/chlorine or persulfate-based AOP workflows\u003c\/li\u003e\n\u003cli\u003eFiducial marker in mass spectrometric imaging (MALDI-TOF) workflows\u003c\/li\u003e\n\u003cli\u003eMembrane documentation and blot-cutting support before downstream immunodetection\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\u003cdiv style=\"margin-bottom: 28px;\"\u003e\n\u003cdiv style=\"background: #002147; padding: 10px 20px; margin-bottom: 0;\"\u003e  \u003ch3 style=\"margin: 0; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 0.70em; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; color: #fff;\"\u003eShipping Destinations\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 1px solid #e4e8f0; border-top: none; padding: 12px 16px; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 0.95em;\"\u003e\u003cul style=\"margin: 0; padding: 0; list-style: none;\"\u003e\n\u003cli style=\"padding: 5px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cspan style=\"display: inline-block; width: 7px; height: 7px; background: #002147; border-radius: 50%; margin-right: 10px; vertical-align: middle;\"\u003e\u003c\/span\u003eEU \u0026amp; UK: Priority delivery, 2–5 business days.\u003c\/li\u003e\n\u003cli style=\"padding: 5px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cspan style=\"display: inline-block; width: 7px; height: 7px; background: #002147; border-radius: 50%; margin-right: 10px; vertical-align: middle;\"\u003e\u003c\/span\u003eUnited States (DDP): 3–7 business days, duties and taxes prepaid.\u003c\/li\u003e\n\u003cli style=\"padding: 5px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cspan style=\"display: inline-block; width: 7px; height: 7px; background: #002147; border-radius: 50%; margin-right: 10px; vertical-align: middle;\"\u003e\u003c\/span\u003eEFTA Countries (DDP): 3–7 business days, duties and taxes prepaid.\u003c\/li\u003e\n\u003cli style=\"padding: 5px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cspan style=\"display: inline-block; width: 7px; height: 7px; background: #002147; border-radius: 50%; margin-right: 10px; vertical-align: middle;\"\u003e\u003c\/span\u003eWorldwide: 7–14 business days, selected locations.\u003c\/li\u003e\n\u003c\/ul\u003e\u003c\/div\u003e\n\u003c\/div\u003e","brand":"NorrChemica™","offers":[{"title":"5.0 g","offer_id":52538524074321,"sku":"NOR-6226795-5g","price":27.0,"currency_code":"EUR","in_stock":true},{"title":"10 g","offer_id":52538524107089,"sku":"NOR-6226795-10g","price":39.0,"currency_code":"EUR","in_stock":true},{"title":"25 g","offer_id":52538524139857,"sku":"NOR-6226795-25g","price":65.0,"currency_code":"EUR","in_stock":true},{"title":"50 g","offer_id":52538524172625,"sku":"NOR-6226795-50g","price":110.0,"currency_code":"EUR","in_stock":true},{"title":"100 g","offer_id":52538524205393,"sku":"NOR-6226795-100g","price":189.99,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0954\/6357\/1793\/files\/NorrChemica_Ponceau_S.png?v=1782695762","url":"https:\/\/www.norrchemica.com\/products\/ponceau-s-acid-red-112-cas-6226-79-5","provider":"NorrChemica","version":"1.0","type":"link"}