fluoresceine - 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)solution - a homogeneous mixture of two or more substances; frequently (but not necessarily) a liquid solution; "he used a solution of peroxide and water" dye, dyestuff - a usually soluble substance for staining or coloring e.g. fabrics or hair bromeosin, 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 |