{"product_id":"fluorescein-cas-2321-07-5","title":"Fluorescein | CAS 2321-07-5 | ≥90% Dye Content","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;\"\u003e2321-07-5\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;\"\u003e219-031-8\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;\"\u003eMFCD00005050\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;\"\u003eLM5075000\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=C2C(=C1)C(=O)OC23C4=C(C=C(C=C4)O)OC5=C3C=CC(=C5)O\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\/C20H12O5\/c21-11-5-7-15-17(9-11)24-18-10-12(22)6-8-16(18)20(15)14-4-2-1-3-13(14)19(23)25-20\/h1-10,21-22H\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;\"\u003eGNBHRKFJIUUOQI-UHFFFAOYSA-N\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;\"\u003e16850\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;\"\u003eC₂₀H₁₂O₅\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;\"\u003e332.31 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;\"\u003e315 °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 methanol (0.1 g\/10 mL), acetone, DMSO, soluble in dilute aqueous bases (1N NaOH)\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;\"\u003e≥90% dye content\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;\"\u003eOrange-red crystalline 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;\"\u003e3204.90\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 in a cool, dry place in a tightly sealed container, protected from light\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\u003eFluorescein\u003c\/strong\u003e (3',6'-dihydroxyspiro[2-benzofuran-3,9'-xanthene]-1-one; resorcinolphthalein; C.I. Solvent Yellow 94; D\u0026amp;C Yellow No. 7) is a synthetic xanthene dye and among the most widely used fluorophores in biological and analytical research. In water it absorbs maximally near 494 nm and emits bright green fluorescence near 521 nm, with strongly pH-dependent spectra (pKa ≈ 6.4) and an isosbestic point at 460 nm. It is the parent fluorophore of the amine-reactive labels fluorescein isothiocyanate (FITC) and NHS-fluorescein, and of the 6-FAM phosphoramidite used to tag synthetic oligonucleotides.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCommon Scientific Applications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFluorescent labelling and bioimaging (FITC, NHS-fluorescein, 6-FAM):\u003c\/strong\u003e Fluorescein-derived reactive labels such as FITC and NHS-fluorescein conjugate to primary amines on proteins, antibodies, and cellular components for immunofluorescence and immunoassays, while the 6-FAM phosphoramidite tags synthetic oligonucleotides for qPCR probes and sequencing. Fluorescein-labelled molecules also act as tracers in cells and tissues.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlow cytometry:\u003c\/strong\u003e FITC excites efficiently at the 488 nm line of argon-ion and solid-state lasers, serving as a standard fluorophore for cell staining and sorting and as an anchor channel in multicolour cytometry panels.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFluorescence quantum-yield standard:\u003c\/strong\u003e In 0.1 M NaOH, fluorescein is a long-standing quantum-yield reference for calibrating fluorescence spectrometers and for determining the quantum yields of new fluorophores by comparative methods.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAnalytical indicator:\u003c\/strong\u003e Acts as an adsorption indicator in argentometric (Fajans) halide titrations, and detects soluble hydroxides, carbonates, and ammonia through the intense green fluorescence it develops in alkaline media, down to trace levels.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHydrological and environmental tracing:\u003c\/strong\u003e A highly detectable, water-soluble tracer for groundwater-flow studies, hydraulic-connection mapping, and leak detection, including hydrostatic and subsea oil-and-gas pipeline leak testing, traceable at very low concentrations over long distances.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eForensic detection of latent blood:\u003c\/strong\u003e Reveals dilute or latent bloodstains by the fluorescence it produces under appropriate illumination, used alongside chemiluminescent methods such as luminol in crime-scene work.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSynthetic precursor to halogenated xanthene dyes:\u003c\/strong\u003e Brominated to give the dye eosin Y, and the parent scaffold of halogenated xanthene dyes such as erythrosine and Rose Bengal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDye-laser gain medium:\u003c\/strong\u003e Lases in the green–yellow region as a classic tunable organic dye-laser medium.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eORAC antioxidant-capacity assay:\u003c\/strong\u003e Serves as the fluorescent probe whose emission decays under a peroxyl-radical flux; antioxidants slow the decay, giving a quantitative measure of antioxidant capacity.\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":53475992273233,"sku":"NOR-2321075-5g","price":22.0,"currency_code":"EUR","in_stock":true},{"title":"10 g","offer_id":53475992306001,"sku":"NOR-2321075-10g","price":32.0,"currency_code":"EUR","in_stock":true},{"title":"25 g","offer_id":53475992338769,"sku":"NOR-2321075-25g","price":48.0,"currency_code":"EUR","in_stock":true},{"title":"50 g","offer_id":53475992371537,"sku":"NOR-2321075-50g","price":72.0,"currency_code":"EUR","in_stock":true},{"title":"100 g","offer_id":53475992404305,"sku":"NOR-2321075-100g","price":119.0,"currency_code":"EUR","in_stock":true},{"title":"250 g","offer_id":53475992437073,"sku":"NOR-2321075-250g","price":235.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0954\/6357\/1793\/files\/Fluorescein_NORRCHEMICAMULTILISTING_90__VR.png?v=1775689307","url":"https:\/\/www.norrchemica.com\/products\/fluorescein-cas-2321-07-5","provider":"NorrChemica","version":"1.0","type":"link"}