Basic Violet 10/Rhodamine B (CAS: 81-88-9)

Rhodamine B is a chemical compound and a dye. It is often used as a tracer dye within water to

determine the rate and direction of flow and transport. Rhodamine dyes fluoresce and can thus be

detected easily and inexpensively with instruments called fluorometers. Rhodamine dyes are used

extensively in biotechnology applications such as fluorescence microscopy, flow cytometry,

fluorescence correlation spectroscopy and ELISA.

Use

Rhodamine B is used in biology as a staining fluorescent dye, sometimes in combination with auramine

O, as the auramine-rhodamine stain to demonstrateacid-fast organisms, notably Mycobacterium.

Rhodamine B is tunable around 610 nm when used as a laser dye. Its luminescence quantum yield is 0.65

in basic ethanol, 0.49 in ethanol, 1.0,and 0.68 in 94% ethanol.[  The fluorescence yield is temperature dependent.

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 vaccinebait. The rhodamine is incorporated into the animal’s whiskers and teeth.

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.

Safety and health

In California, Rhodamine B is suspected to be carcinogenic and thus products containing it must contain a warning on its label.

In New   Jersey, MSDS files state that there is limited evidence of carcinogenicity in laboratory animal, and no evidence at all in humans.