Definition of orcein in English:



mass nounChemistry
  • A red dye obtained from orchil, used as a microscopic stain.

    • ‘Chromosomes were counted in root tips stained with acetic orcein.’
    • ‘The chromosomes were stained with acetic orcein and visualized with a light microscope.’
    • ‘After air drying, the cells were stained with 2% acetic orcein.’
    • ‘The anthers of each flower were squashed in a drop of 2% acetic orcein to intensify the staining of meiotic cells.’
    • ‘The slide was immersed in 1% orcein in 45% acetic acid for 15 min, washed in distilled water, air-dried and a coverslip was mounted in Histomount (National Diagnostics, Hull, UK).’


Mid 19th century: alteration of orcin, another name for orcinol.