Description

Eosin B is a synthetic, water-soluble xanthene dye belonging to the eosin family, valued for its distinct bluish-red color and staining properties. This compound is a critical tool in histology and cytology for differentiating cellular structures, providing high contrast and clarity in microscopic analysis. It is essential for professionals in biomedical research, diagnostic laboratories, and industrial staining applications requiring reliable and consistent biological dyes.

Application

• Histological Staining: Used as a counterstain in combination with hematoxylin (H&E staining variants) to differentiate cytoplasm, collagen, and muscle fibers in tissue sections.
• Cytological Analysis: Employed in blood smear staining (e.g., Romanowsky-type stains) and for visualizing cellular details in cytology preparations.
• Microbiological Staining: Applied in selective staining protocols for bacteria and other microorganisms under light microscopy.
• Ink & Dye Manufacturing: Serves as a colorant in the formulation of specialized inks, including ballpoint pen inks and stamp pad dyes.
• Textile Dyeing: Utilized for dyeing silk, wool, and nylon fibers, offering a vibrant bluish-red hue.
• Paper and Leather Coloring: Acts as a pigment for coloring paper products and leather goods.
• Fluorescence Microscopy: Can be used as a fluorescent tracer in certain biological imaging applications due to its xanthene structure.
• Quality Control Reagent: Functions as a standard or indicator in various analytical and laboratory control procedures.

Basic Information

Product Name	Eosin B
CAS No.	56360-46-4
Molecular Formula	C20H6Br4Na2O5
Molecular Weight	691.87 g/mol
Synonyms	Acid Red 91; C.I. 45400; Eosin Scarlet; Eosin B, water soluble; Eosin Bluish; Bromoeosin; 2',4',5',7'-Tetrabromo-3',6'-dihydroxyspiro[isobenzofuran-1(3H),9'-[9H]xanthen]-3-one disodium salt; Eosin B (tetrabromofluorescein sodium salt)
EINECS	260-184-6

Quality Control

Our Eosin B is produced and tested under a stringent quality management system to ensure batch-to-batch consistency and performance reliability for critical applications. Each lot is analyzed to meet high-purity standards typical for biological staining, with key parameters including color strength, solubility, and absence of interfering impurities. A comprehensive Certificate of Analysis (COA) detailing purity, identity, and performance tests is provided with every shipment to support your quality assurance protocols.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at a controlled room temperature (15-25°C). Keep the container tightly sealed when not in use to protect against moisture and contamination.

Specification

Item	Specification
Appearance	Reddish-brown to bluish-red powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 85% (Dye content)
Color Strength	95 - 105% (vs. Standard)
Solubility (in Water)	Clear, complete solution
Loss on Drying	≤ 5.0 %
Residue on Ignition (Sulfated Ash)	≤ 2.0 %
Heavy Metals (as Pb)	≤ 20 ppm

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