Rhodamine B is being tested for use as a biomarker in oral rabies vaccines for wildlife, such as raccoons, to identify animals that have eaten a vaccine bait. The rhodamine is incorporated into the animal's whiskers and teeth.[8]
It is also often mixed with herbicides to show where they have been used.
Rhodamine B (BV10) is mixed with Quinacridone Magenta (PR122) to make the bright pink watercolor known as Opera Rose.[9]
Rhodamine B is used in biology as a staining fluorescent dye, sometimes in combination with auramine O, as the auramine-rhodamine stain to demonstrate acid-fast organisms, notably Mycobacterium.