Safranine O

Safranine O, also known simply as safranin, is a biological stain used widely in histology, cytology, and microbiology. It is a basic dye that binds strongly to acidic (negatively charged) cellular components and is best known for its red or pink coloration of tissues.

🏭⚗️ Production
Safranine O is synthesized as a synthetic basic dye, typically from aniline derivatives through multi-step chemical processes involving diazotization and coupling reactions. It is supplied as a powder or solution, and is soluble in water and ethanol. Stock solutions are usually prepared in distilled water or alcohol, depending on the protocol.

🔬 Properties
Safranine O appears as a bright red powder and yields a pink to red coloration in staining procedures. It binds selectively to acidic tissue components such as nucleic acids and lignified plant cell walls. It has a strong affinity for nuclei and cartilage and functions well as a counterstain due to its contrast with other primary stains. It is pH-sensitive and works optimally in slightly acidic to neutral environments.

🧪 Applications
• Histology: Used as a nuclear counterstain in Gram staining, H&E alternatives, and in various plant tissue protocols.
• Microbiology: Serves as the red counterstain in Gram staining to differentiate Gram-negative bacteria (which stain pink) from Gram-positive ones.
• Botany: Widely used to stain plant tissues—particularly xylem, lignin, and cell walls—in combination with fast green or other contrasting dyes.
• Cytology: Helps visualize nuclei and certain cytoplasmic components in smears and sectioned tissue samples.
• Teaching & Demonstration: Commonly used in educational labs to highlight basic cellular structures for microscope observation.