Phloxine B is primarily used as a biological stain in microscopy, where it helps in highlighting cellular structures for better visualization under a microscope. It is also employed in the food industry as a color additive, particularly in products like candies and desserts, to impart a bright red or pink hue. In the field of entomology, it serves as an effective dye for marking insects in ecological studies, aiding in tracking their movements and behaviors. Additionally, Phloxine B has been utilized in photodynamic therapy for its ability to generate reactive oxygen species when exposed to light, making it useful in targeting and destroying certain types of cells, such as cancer cells or bacteria. Its application in water treatment processes includes acting as a photosensitizer to degrade organic pollutants under light exposure.