Fluorescein (Solvent Yellow 94): Industrial Applications, Product Specifications and Sourcing Considerations
Introduction Fluorescein is a synthetic fluorescent dye known for its bright yellow-green fluorescence under suitable lighting conditions. It belongs to the xanthene dye family and is used in analytical chemistry, laboratory testing, microscopy, and select industrial applications that require fluorescence detection. Also identified as Solvent Yellow 94, Fluorescein is available in different chemical forms and grades. Its performance depends on factors such as purity, solubility, pH, concentration, and the conditions in which it is used. For manufacturers, distributors, and industrial buyers, understanding these properties is important before selecting a suitable grade. This guide covers Fluorescein’s chemical identity, applications, product specifications, quality requirements, and sourcing considerations. What Is Fluorescein (Solvent Yellow 94)? Fluorescein is an organic synthetic dye with the molecular formula C20H12O5 and a molecular weight of approximately 332.31 g/mol. Its CAS number is 2321-07-5. It is generally supplied as a yellow powder or orange-red crystalline material. One of its main characteristics is its strong yellow-green fluorescence under suitable light, particularly in alkaline solutions. Key chemical identification details: Chemical nameFluoresceinCommon nameSolvent Yellow 94CAS number2321-07-5Molecular formulaC20H12O5Molecular weight332.31 g/molChemical familyXanthene dyesAppearanceYellow powder or orange-red crystalsWater solubilityInsoluble in waterSolubilitySoluble in dilute aqueous bases One important distinction is between Fluorescein and Sodium Fluorescein. Sodium