#stain  a dye or other coloring material that is used in microscopy to make structures visible
  supertype:  coloring_material__colouring_material__colouringmaterial__color__colour  any material used for its color
  subtype:  gentian_violet__gentianviolet__crystal_violet__crystalviolet  a green crystal (violet in water) used as a dye or stain or bactericide or fungicide or anthelmintic or burn treatment
  subtype:  methylene_blue__methyleneblue__methylthioninechloride  a dark green dye used as a stain, an antiseptic, a chemical indicator, and an antidote in cyanide poisoning

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