eosin

e·o·sin  (-sn)

n.

1. A red crystalline powder, C₂₀H₈O₅Br₄, used in textile dyeing and ink manufacturing and in coloring gasoline.

2. The red sodium or potassium salt of this powder, used in biology to stain cells.

---

[Greek s, dawn (from its color); see aus- in Indo-European roots + -in.]

Thesaurus

Noun

1.

eosin - a red fluorescent dye resulting from the action of bromine on fluorescein; used in cosmetics and as a biological stain for studying cell structures bromeosin fluorescein, fluoresceine, fluorescent dye, resorcinolphthalein - a yellow dye that is visible even when highly diluted; used as an absorption indicator when silver nitrate solution is added to sodium chloride in order to precipitate silver chloride (turns pink when no chloride ions are left in solution and negative fluorescein ions are then absorbed)