tolonium chloride

Tolonium chloride is a cationic phenothiazine dye used primarily as a histological stain and as a diagnostic vital dye, with high affinity for acidic tissue components such as nucleic acids (DNA and RNA) due to electrostatic interactions, enabling selective staining of dysplastic or malignant mucosa and other tissues rich in nucleic acids.[2][4] It has been used clinically as an adjunctive diagnostic aid for oral and gastric neoplasms and to help identify parathyroid glands during thyroid surgery; it has also been explored as a photosensitizer in antimicrobial photodynamic therapy in periodontal disease.[1][2][6] Mechanistically, it binds to polyanionic macromolecules (DNA/RNA) and can act as a fluorochrome/metachromatic dye; under light activation (e.g., 635 nm), it generates reactive oxygen species for photodynamic effects.[1][2][6]

Brand names

OraTest

Other names

Toluidine blue OToluidine blueBasic Blue 17C.I. 520403-amino-7-(dimethylamino)-2-methylphenothiazin-5-ium chlorideTBO