Fluorescein Sodium CAS No.: 518-47-8 biological staining agent

Product Overview:

Ferrozine (monosodium salt) is a fluorescent tracer widely used in medicine and biology, including tumor and infected tissue tracing. It is Orange to brown powder; freely soluble in water, slightly soluble in ethanol, giving a yellow-green fluorescent solution. Its applications include cell and tissue fluorescent staining, vital staining, fluorescence microscopy, and diagnostic fluorescent tracing. Our products are for research and in vitro diagnostic use only.

Product information:

Frequently Asked Questions (FAQ)

Q1: What is Fluorescein Sodium and what is it mainly used for?

A: It is a fluorescent tracer that emits yellow-green fluorescence under blue light excitation, used for labeling and tracking cells, tissues, and pathological lesions.

Q2: What are its applications in medicine?

A: It is used for clinical diagnostic fluorescent tracing, such as fundus angiography, corneal damage detection, circulation time measurement, as well as tracing and localization of tumors and infected tissues. Medical use must meet compendial standards such as USP (biological stain grade is for research and in vitro diagnostic use only).

Q3: What are its uses in biological/research experiments?

A: It is used for fluorescent staining of cells and tissues, vital staining, fluorescence microscopy observation, and fluorescent tracing in cell and fluid studies.

Q4: Why is it well suited for biological fluorescent labeling?

A: It is readily soluble in water with high fluorescence intensity and can be detected at very low concentrations. Under blue light excitation it emits yellow-green fluorescence with clear contrast against the background, making it easy to observe and locate targets.

Q5: What should be noted for use and storage?

A: Store sealed, protected from light, in a cool and dry place. Avoid mixing with acids, acid salts, or heavy metal salts. For research and in vitro diagnostic use only; not for direct injection into the human body.

Application Cases

Case 1: Cell Viability Indication (Live/Dead Assay)

Cells are treated with fluorescein diacetate (FDA, which can be prepared from fluorescein sodium): in living cells, esterases hydrolyze FDA to fluorescein, which emits green fluorescence under blue light excitation; dead cells lack enzyme activity and show no fluorescence. Combined with PI double staining, live and dead cells can be distinguished simultaneously — a common indicator method in cytotoxicity assays.

Case 2: Immunofluorescence Labeling (FITC-Conjugated Antibodies)

Fluorescein sodium is a raw material for FITC (fluorescein isothiocyanate). FITC is conjugated to antibodies, which then label target proteins or microorganisms through antigen-antibody reactions, producing green fluorescent signals under fluorescence microscopy. Widely used in immunohistochemistry, flow cytometry, and pathogen detection.

Case 3: Microbial Activity and Morphology Observation

Low-concentration fluorescein sodium is used to stain microorganisms such as bacteria and fungi; viable cells emit yellow-green fluorescence under blue light excitation. This enables observation of microbial morphology, activity, and biofilm distribution under fluorescence microscopy, serving as an auxiliary indicator in microbiological research.

Case 4: Barrier Permeability Tracing

Fluorescein sodium is injected into experimental animals or isolated tissue systems, and its fluorescent properties are used to trace molecular passage across membranes/barriers (e.g., blood-brain barrier, vascular endothelium). Fluorescence intensity quantitatively indicates changes in barrier integrity.

Case 5: pH and Fluorescence Intensity Indication

The fluorescence intensity of fluorescein sodium varies with solution pH (fluorescence decreases in acidic environments), allowing its use as a fluorescent pH indicator in biological systems to monitor acid-base changes in or around cells, with quantitative detection via fluorescence microscopy or fluorescence spectrophotometry.

Safety and Storage

• Safety: Not dangerous goods.For research and in vitro diagnostic use only; not for human injection. Avoid contact with eyes, skin, and dust; wear gloves and goggles. Do not mix with acids, acid salts, or heavy metal salts.
• Storage: Keep sealed, protected from light, in a cool, dry place (10–30°C).
• Shelf Life: 24 months when stored properly.

Product Manager:

Grace Zhang  E-mail: grace@coreychem.com