Definition of toluidine blue in English:

toluidine blue


mass noun
  • A synthetic blue dye used chiefly as a stain in biology.

    A thiazine dye; chemical formula: C₁₅H₁₆ClN₃S

    • ‘The matrix or ground substance of cartilage is strongly basophilic and stains metachromatically with toluidine blue and other similar basic dyes.’
    • ‘Inactive DNA is readily stained with hematoxylin, toluidine blue, and other similar basic dyes.’
    • ‘Thick sections were stained with alkaline toluidine blue for light microscopic examination and selection of areas for electron microscopic study.’
    • ‘Specimens were stained with toluidine blue and basic fuchsin.’
    • ‘The cytoplasm of medullar cells stains deeply with toluidine blue, while the cytoplasm of cortical cells stains faintly.’


Late 19th century: toluidine from toluene + -ide + -ine.


toluidine blue