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)
例句
用作名词(n.)
Now, I will apply a drop of fluorescein on your eye.来，给你的眼睛滴一点荧光素。
