Rose bengal is a stain. Rose bengal belongs to the class of organic compounds called xanthenes. Its sodium salt is commonly used in eye drops to stain damaged conjunctival and corneal cells and thereby identify damage to the eye. The stain is also used in the preparation of Foraminifera for microscopic analysis, allowing the distinction between forms that were alive or dead at the time of collection.
Rose Bengal (RB) is a red synthetic dye that was initially used in the garment industry and has been used safely for decades as a corneal stain by ophthalmologists.
Rose bengal is used to suppress bacterial growth in several microbiological media, including Cooke's rose bengal agar. Rose bengal has been used as a protoplasm stain to discriminate between living and dead micro-organisms, particularly Foraminifera, since the 1950s when Bill Walton developed the technique.
Rose bengal is a pink stain derived as an analogue of fluorescein. Its disodium salt in ophthalmic solutions has been used as a diagnostic agent in suspected damage to conjunctival and corneal cells.