according to Conn
according to Merck
Rhodamine B is an amphoteric dye, although usually listed as basic as it has an overall positive charge. It is most commonly used as a fluorochrome, an example being in mixture with auramine O to demonstrate acid fast organisms.
The structural formula given in the Merck Index is slightly different than in Conn, having methyl groups instead of ethyl groups.
R. D. Lillie.
Conn's Biological Stains
Williams & Wilkins, Baltimore, MD., U.S.A.
Edward Gurr, (1971)
Synthetic dyes in biology, medicine and chemistry
Academic Press, London, England.
Aldrich chemical catalogue, 1992
Aldrich Chemical Company, Milwaukee, WI, USA.
Susan Budavari, Editor, (1996)
The Merck Index, Ed. 12
Merck & Co., Inc., Whitehouse Station, NJ, USA