Fluorescein Dye – 500 gram Packs

Fluorescein Dye is an organic fluorescent compound belonging to the xanthene dye family, widely used in laboratory investigations that involve fluorescence, optical detection, and analytical chemistry. The compound, also known as resorcinolphthalein or Solvent Yellow 94, has the chemical formula C₂₀H₁₂O₅ and a molecular weight of approximately 332.31 g/mol. It generally appears as a yellow amorphous solid or an orange-red to reddish-brown powder, depending on its physical form. Fluorescein is poorly soluble in water but dissolves in dilute alkaline solutions, where it produces intense greenish-yellow fluorescence. This characteristic makes it useful for fluorescence demonstrations, microscopy, selected analytical procedures, and tracer investigations. Its suitability for a specific experiment depends on the required grade, purity, and method. This 500 g pack is intended for laboratory and research applications where the supplied specifications meet experimental requirements.

Product Specifications

Specification	Details
Appearance	Orange-red to reddish-brown powder
Assay	99%
Chemical Name	Fluorescein
Alternate Names	Resorcinolphthalein; Fluorescein Acid; Yellow Fluorescein; Solvent Yellow 94
Molecular Formula	C₂₀H₁₂O₅
Empirical Formula	C₂₀H₁₂O₅
CAS Number	2321-07-5
Molecular Weight	332.31 g/mol
Grade	LR Laboratory Reagent

Key Features of Fluorescein Dye

• Fluorescent organic compound: Belongs to the xanthene dye family and exhibits characteristic greenish-yellow fluorescence under suitable excitation conditions.
• Defined chemical composition: Has the molecular formula C₂₀H₁₂O₅ and a molecular weight of approximately 332.31 g/mol.
• Characteristic appearance: Commonly occurs as an orange-red to reddish-brown powder or yellow amorphous solid.
• pH-dependent optical behaviour: Produces intense fluorescence in dilute alkaline solutions, making it useful for studying fluorescence and acid–base effects.
• Laboratory versatility: Supports selected analytical chemistry, microscopy, fluorescence, and tracer investigations when its specifications match the method.

Laboratory Applications of Fluorescein Dye

• Fluorescence demonstrations: Used in supervised chemistry experiments to demonstrate fluorescence and the influence of solution conditions on optical behaviour.
• Analytical chemistry: Used as a fluorescent indicator in selected analytical procedures, including appropriate precipitation titrations.
• Microscopy research: Applied in suitable fluorescence-based investigations where the dye’s properties and method requirements are compatible.
• Tracer studies: Used in selected laboratory investigations to observe movement and distribution in suitable aqueous or alkaline systems.
• Optical and photochemical research: Serves as a fluorescent compound for studying absorption, emission, and related optical properties under controlled experimental conditions.

Why Choose Lab Wale to Buy Fluorescein Dye

Lab Wale provides a sourcing option for laboratory chemicals and scientific supplies used by schools, colleges, universities, research centres, and laboratory professionals. When purchasing Fluorescein Dye, consider the chemical identity, assay, grade, physical form, and applicable safety information to ensure suitability for the intended application. The 500 g pack format may suit laboratories planning reagent requirements for teaching, analytical work, or research. Checking product specifications before purchase helps support appropriate selection, accurate experimental planning, and laboratory inventory management.

Frequently Asked Questions About Fluorescein Dye

What is Fluorescein Dye used for in laboratories?

Fluorescein is used in fluorescence demonstrations, microscopy, selected analytical procedures, and tracer investigations. Its optical properties make it useful for observing fluorescence and studying the effects of solution conditions on emission. The appropriate application depends on the required grade, concentration, and validated experimental method.

What is the chemical formula and molecular weight of Fluorescein?

Fluorescein has the molecular formula C₂₀H₁₂O₅ and a molecular weight of approximately 332.31 g/mol. Its empirical formula is the same because the atom ratio cannot be reduced to smaller whole numbers. These values refer to fluorescein itself, not its sodium or potassium salts.

What is the CAS number of Fluorescein Dye?

The CAS Registry Number for fluorescein is 2321-07-5. This identifier applies to the fluorescein compound and distinguishes it from related salts, such as sodium fluorescein, which have different chemical compositions and identifiers. Confirming the exact form is important when selecting a reagent for laboratory work.

Why does Fluorescein produce greenish-yellow fluorescence?

Fluorescein absorbs light at suitable wavelengths and emits light at longer wavelengths, producing visible fluorescence. Its optical response depends on factors such as pH, solvent, concentration, and excitation wavelength. Dilute alkaline solutions commonly exhibit particularly strong greenish-yellow fluorescence under appropriate illumination.

How should Fluorescein Dye be stored and handled?

Store fluorescein in a tightly closed, properly labelled container under the conditions specified in the applicable Safety Data Sheet. Protect the material from contamination and prolonged exposure to strong light. Wear suitable gloves, protective clothing, and eye protection, and avoid inhaling dust during weighing or transfer.

Storage Conditions for Fluorescein Dye

Store Fluorescein Dye in a compatible, tightly closed, clearly labelled container in a dry laboratory storage area at the temperature specified by the supplier. Protect the material from prolonged exposure to strong light and prevent contamination during handling. Follow the applicable safety documentation for any additional storage requirements and segregation from incompatible substances.

Precautions for Handling Fluorescein Dye

Review the applicable Safety Data Sheet before use. Wear suitable laboratory gloves, protective clothing, and safety goggles, and avoid inhaling airborne powder or allowing contact with the eyes. Use appropriate ventilation during weighing and transfer. Prevent contamination, clean spills using methods that minimize dust generation, and follow institutional procedures for chemical waste disposal and emergency response.