Use in histology Sample of a trachea coloured with hematoxylin and<unk> .<unk>  is most often used as a counterstain to hematoxylin in H&E (haematoxylin and<unk>  staining. H&E staining is one of the most commonly used techniques in histology. Tissue stained with haematoxylin and<unk>  shows cytoplasm stained pink-orange and nuclei stained darkly, either blue or purple.<unk>  also stains red blood cells intensely red. For staining,<unk>  Y is typically used in concentrations of 1 to 5 percent weight by volume, dissolved in water or ethanol. For prevention of mold growth in aqueous solutions, thymol is sometimes added. A small concentration (0.5 percent) of acetic acid usually gives a deeper red stain to the tissue. It is listed as an IARC class 3 carcinogen. Other uses In his Field with Irises near Arles painting, Van Gogh incorporated red<unk>  dye into the color of the irises depicted at the bottom of the painting. Due to<unk> 's tendency to fade, the petals have now attained a blueish hue from their original purple coloration.<unk>  is also used as a red dye in inks; however, the molecule, especially that of<unk>  Y, tends to degrade over time, leaving behind its bromine atoms, hence causing paint incorporating such a dye to obtain a darker brown tinge over time. A notable user of<unk>  dye was the post-impressionist painter Van Gogh.
Eosin
Muscle spindle
Gumma 
Neurilemma
Lens
Lens 
Subtitles
Athelia 