Description

Eosin Disodium CAS NO 17372-87-1 is a water-soluble, synthetic xanthene dye widely recognized for its intense red fluorescence under blue or ultraviolet light. This high-purity compound is essential for precise staining and detection protocols across life science and industrial applications. It is a critical reagent for researchers and manufacturers in histology, cytology, and diagnostic testing who require consistent, high-quality staining results.

Application

• Histological Staining: A primary counterstain in hematoxylin and eosin (H&E) staining for visualizing cytoplasmic structures, collagen, and muscle fibers in tissue sections.
• Cytological Analysis: Used in Pap smears and other cytological preparations to stain cell cytoplasm and differentiate cell types.
• Fluorescence Microscopy & Assays: Employed as a fluorescent tracer or viability stain due to its distinct emission properties.
• Blood Cell Staining: A key component in Romanowsky-type stains (e.g., Wright's stain) for differentiating blood cells in peripheral blood smears.
• Industrial Dyeing: Used as a colorant in inks, textiles, and biological indicators.
• Quality Control Reagent: Applied in pharmaceutical and cosmetic industries for product testing and formulation.

Basic Information

Product Name	Eosin Disodium
CAS No.	17372-87-1
Molecular Formula	C20H6Br4Na2O5
Molecular Weight	691.86 g/mol
Synonyms	Eosin Y, Disodium Salt; Acid Red 87; C.I. 45380; Bromoeosin; Eosin Yellowish; Eosin Water Soluble; 2',4',5',7'-Tetrabromofluorescein disodium salt; Eosin, sodium salt
EINECS	241-409-6

Quality Control

Our Eosin Disodium is manufactured under strict quality management systems to ensure batch-to-batch consistency and high purity suitable for diagnostic and research applications. Each lot is tested against stringent in-house specifications, including identity, purity, and performance in staining. A comprehensive Certificate of Analysis (COA) detailing assay, impurity profiles, and other critical parameters is provided with every shipment.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at room temperature (15-25°C). This material is light-sensitive (store away from light).

Specification

Item	Specification
Appearance	Red to brownish-red powder
Identification (IR)	Conforms to standard
Assay (HPLC)	≥ 85.0% (as Eosin)
Loss on Drying	≤ 10.0 %
Absorbance (λ max)	515 - 520 nm
Fluorescence	Exhibits characteristic red fluorescence
Solubility (in Water)	Clear, red solution
Heavy Metals (as Pb)	≤ 20 ppm

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.