Description

Basic Red 51 is a synthetic organic dye classified as a cationic (basic) dye, primarily used in textile, paper, and leather industries for coloring purposes. It is known for its bright red color, good water solubility, and strong affinity for anionic substrates like wool, silk, and acrylic fibers. Chemically, it belongs to the azo dye family, meaning it contains one or more azo groups (-N=N-) linking aromatic rings, which contribute to its vivid coloration. Basic Red 51 is often utilized in laboratory staining, especially for cellular and histological staining, due to its ability to bind to negatively charged cellular components like nucleic acids. It exhibits moderate light and washing fastness, making it suitable for applications where vibrant color is desired but extreme durability is not critical. Handling requires care, as it can cause skin and eye irritation and may pose environmental hazards if disposed of improperly.

Chemical Structure of Basic Red 51

Appearance of Basic Red 51

Uses

1. Textile Industry

Packing

Export Worthy packing 5 Kg Drum, 25 Kg Drum, 50 Kg Drum.

Storage Conditions

Store in cool and dry place at room temperature, protect from direct sunlight.

Molecular Formula

CAS No.

CI No.

IUPAC Name

Synonyms

Molecular Weight

Appearance

Solubility

Dye Content (Spectrophotometry)

C17​H19​ClN4​

569-61-9

77061

[4-(dimethylamino)phenylazo]benzenaminium chloride

Benzenaminium, 4-(dimethylamino)phenylazo-, chloride

279.77 g/mol

red powder or bluish-violet powder in the literature.

98%

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Basic Red 51 is primarily used as a cationic dye for dyeing fibers with anionic sites, such as acrylic fibers, wool, and silk. Its bright red shade makes it popular for garments, decorative fabrics, and costumes. It provides vivid, uniform coloration and is often used in blends with other dyes to achieve specific shades. However, it has moderate fastness properties, so it is typically chosen for fabrics that are not frequently exposed to harsh washing or sunlight.

2. Leather and Paper Industry

In leather processing, Basic Red 51 is used to impart bright red color to tanned leather products like shoes, handbags, and accessories. In the paper industry, it is used to color paper, cardboard, and pulp products where vibrant color is required, often for packaging, decorative printing, or specialty papers.

3. Biological and Laboratory Applications

4. Industrial and Research Uses

5. Environmental and Safety Considerations

This dye is widely used in histology and cytology for staining purposes. Because it is a cationic dye, it binds strongly to negatively charged cellular components such as nucleic acids (DNA and RNA) and certain cytoplasmic proteins. Specific uses include:

• Staining of cell nuclei and cytoplasm for microscopy.

• Gram staining adjuncts in microbiology.

• Counterstaining in combination with other dyes to enhance contrast in tissue sections.

Basic Red 51 is also used in ink formulations, plastics, and coatings where a bright, stable red color is desired. Its solubility in water allows it to be used in aqueous coloring systems for laboratory experiments and industrial applications.

Due to its synthetic origin, improper disposal can lead to water pollution. It is moderately toxic to aquatic life and requires careful handling in industrial and lab settings.

soluble in water and alcohol (like methanol)