Rhodamine B

From Wikipedia, the free encyclopedia
Rhodamine B
Preferred IUPAC name
9-(2-Carboxyphenyl)-6-(diethylamino)-N,N-diethyl-3H-xanthen-3-iminium chloride
Other names
Rhodamine 610, C.I. Pigment Violet 1, Basic Violet 10, C.I. 45170
3D model (JSmol)
ECHA InfoCard 100.001.259 Edit this at Wikidata
  • InChI=1S/C28H30N2O3.ClH/c1-5-29(6-2)19-13-15-23-25(17-19)33-26-18-20(30(7-3)8-4)14-16-24(26)27(23)21-11-9-10-12-22(21)28(31)32;/h9-18H,5-8H2,1-4H3;1H checkY
  • CCN(CC)C1=CC2=C(C=C1)C(=C3C=CC(=[N+](CC)CC)C=C3O2)C4=CC=CC=C4C(=O)O.[Cl-]
Molar mass 479.02
Appearance red to violet powder
Melting point 210 to 211 °C (410 to 412 °F; 483 to 484 K) (Decomposes)
8 to 15 g/L (20 °C)[1][nt 1]
Safety data sheet (SDS) MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Rhodamine B /ˈrdəmn/ 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 fluorometers.

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. Rhodamine dyes are also used extensively in biotechnology applications such as fluorescence microscopy, flow cytometry, fluorescence correlation spectroscopy and ELISA.[citation needed]

Other uses[edit]

Rhodamine B solution in water

Rhodamine B is often mixed with herbicides to show where they have been used.[2]

It is also 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.[3] Rhodamine B is an important hydrophilic xanthene dye well known for its stability and is widely used in the textile industry, leather, paper printing, paint, coloured glass and plastic industries.[4]

Rhodamine B (BV10) is mixed with quinacridone magenta (PR122) to make the bright pink watercolor known as Opera Rose.[5]


A is the "open" form and B is the "closed" form
Rhodamine B closed form (A) and open form (B)

Rhodamine B can exist in equilibrium between two forms: an "open"/fluorescent form and a "closed"/nonfluorescent spirolactone form. The "open" form dominates in acidic condition while the "closed" form is colorless in basic condition.[6]

The fluorescence intensity of rhodamine B will decrease as temperature increases.[7]

The solubility of rhodamine B in water varies by manufacturer, and has been reported as 8 g/L and ~15 g/L,[1] while solubility in alcohol (presumably ethanol) has been reported as 15 g/L.[nt 1] Chlorinated tap water decomposes rhodamine B. Rhodamine B solutions adsorb to plastics and should be kept in glass.[8] Rhodamine B is tunable around 610 nm when used as a laser dye.[9] Its luminescence quantum yield is 0.65 in basic ethanol,[10] 0.49 in ethanol,[11] 1.0,[12] and 0.68 in 94% ethanol.[13] The fluorescence yield is temperature dependent;[14] the compound is fluxional in that its excitability is in thermal equilibrium at room temperature.[15]

Safety and health[edit]

In California, rhodamine B is suspected to be carcinogenic and thus products containing it must contain a warning on its label.[16] Cases of economically motivated adulteration, where it has been illegally used to impart a red color to chili powder, have come to the attention of food safety regulators.[17]

See also[edit]


  1. ^ a b "Safety data sheet" (PDF). Roth. 2013.
  2. ^ Cai SS, Stark JD (November 1997). "Evaluation of five fluorescent dyes and triethyl phosphate as atmospheric tracers of agricultural sprays". Journal of Environmental Science and Health, Part B. 32 (6): 969–83. doi:10.1080/03601239709373123.
  3. ^ Slate D, Algeo TP, Nelson KM, et al. (December 2009). Bethony JM (ed.). "Oral rabies vaccination in north america: opportunities, complexities, and challenges". PLOS Neglected Tropical Diseases. 3 (12): e549. doi:10.1371/journal.pntd.0000549. PMC 2791170. PMID 20027214.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  4. ^ Sudarshan, Shanmugam; Bharti, Vidya Shree; Harikrishnan, Sekar; Shukla, Satya Prakash; RathiBhuvaneswari, Govindarajan (2 October 2022). "Eco-toxicological effect of a commercial dye Rhodamine B on freshwater microalgae Chlorella vulgaris". Archives of Microbiology. 204 (10): 658. doi:10.1007/s00203-022-03254-5.
  5. ^ MacEvoy B. "Handprint: color making attributes". www.handprint.com.
  6. ^ Birtalan E, Rudat B, Kölmel DK, et al. (2011). "Investigating rhodamine B-labeled peptoids: scopes and limitations of its applications". Biopolymers. 96 (5): 694–701. doi:10.1002/bip.21617. PMID 22180914.
  7. ^ Chauhan VM, Hopper RH, Ali SZ, et al. (March 2014). "Thermo-optical characterization of fluorescent rhodamine B based temperature-sensitive nanosensors using a CMOS MEMS micro-hotplate". Sensors and Actuators. B, Chemical. 192: 126–133. doi:10.1016/j.snb.2013.10.042. PMC 4376176. PMID 25844025.
  8. ^ Bedmar AP, Araguás LA (2002). Detection and Prevention of Leaks from Dams. Taylor & Francis. ISBN 90-5809-355-7.
  9. ^ Prahl S. "Rhodamine B". OMLC.
  10. ^ Kubin R (1982). "Fluorescence quantum yields of some rhodamine dyes" (PDF). Journal of Luminescence. 27 (4): 455–462. Bibcode:1982JLum...27..455K. doi:10.1016/0022-2313(82)90045-X.
  11. ^ Casey KG, Quitevis EL (1988). "Effect of solvent polarity on nonradiative processes in xanthene dyes: Rhodamine B in normal alcohols". The Journal of Physical Chemistry. 92 (23): 6590–6594. doi:10.1021/j100334a023.
  12. ^ Kellogg RE, Bennett RG (1964). "Radiationless Intermolecular Energy Transfer. III. Determination of Phosphorescence Efficiencies". The Journal of Chemical Physics. 41 (10): 3042–3045. Bibcode:1964JChPh..41.3042K. doi:10.1063/1.1725672.
  13. ^ Snare M (1982). "The photophysics of rhodamine B". Journal of Photochemistry. 18 (4): 335–346. doi:10.1016/0047-2670(82)87023-8.
  14. ^ Karstens T, Kobs K (1980). "Rhodamine B and rhodamine 101 as reference substances for fluorescence quantum yield measurements". The Journal of Physical Chemistry. 84 (14): 1871–1872. doi:10.1021/j100451a030.
  15. ^ Strack R (May 2019). "Bypassing bleaching with fluxional fluorophores". Nature Methods (Paper). 16 (5): 357. doi:10.1038/s41592-019-0402-2. PMID 31040423.(subscription required)
  16. ^ "Naval Jelly MSDS with Rhodamine B" (PDF). Locite Corporation. 20 October 1998. Archived from the original (PDF) on 2010-04-15.
  17. ^ Lin S (2015). "Rapid and sensitive SERS method for determination of Rhodamine B in chili powder with paper-based substrates". Analytical Methods. 7 (12): 5289. doi:10.1039/c5ay00028a. Retrieved 1 February 2018.


  1. ^ a b Ellis RC (November 16, 2015). "Reagent and Dye Solubility Chart". IHCWorld. Retrieved 9 February 2020. This is to be used as a guide only as solubility data varies between manufacturers for the same product, especially for dyes. Note that most sources simply indicate that the compound is water soluble without providing a g/L value.