Rhodamine: Difference between revisions

[[File:Rodamiini lahustumine veeklaasis.jpg|thumb|Rhodamine in water.]]

'''Rhodamine''' {{IPAc-en|ˈ|r|oʊ|d|əm|iː|n}} is a family of related dyes, a subset of the [[triarylmethane dye]]s. They are derivatives of [[xanthene]]. Important members of the rhodamine family are [[Rhodaminerhodamine 6G]], [[Rhodaminerhodamine 123]], and [[Rhodaminerhodamine B]]. They are mainly used to dye paper and inks, but they lack the [[lightfastness]] for fabric dyeing.<ref name=Ull>{{Ullmann's | last1 = Gessner | first1 = Thomas | last2 = Mayer | first2 = Udo | title = Triarylmethane and Diarylmethane Dyes | year = 2000 | doi = 10.1002/14356007.a27_179}}</ref>

Aside from their major applications, they are often used as a [[tracer dye]], e.g. to determine the rate and direction of flow and transport of water. Rhodamine dyes [[fluorescence|fluoresce]] and can thus be detected easily and inexpensively with instruments calledusing [[fluorometerFluorometer]]s. Rhodamine dyes are used extensively in biotechnology applications such as [[Fluorescence microscope|fluorescence microscopy]], [[flow cytometry]], [[fluorescence correlation spectroscopy]] and [[ELISA]].<ref>{{Cite journal |last1=Zehentbauer |first1=Florian M. |last2=Moretto |first2=Claudia |last3=Stephen |first3=Ryan |last4=Thevar |first4=Thangavel |last5=Gilchrist |first5=John R. |last6=Pokrajac |first6=Dubravka |last7=Richard |first7=Katherine L. |last8=Kiefer |first8=Johannes |date=2014-03-05 |title=Fluorescence spectroscopy of Rhodamine 6G: Concentration and solvent effects |url=https://www.sciencedirect.com/science/article/pii/S1386142513012195 |journal=Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy |volume=121 |pages=147–151 |doi=10.1016/j.saa.2013.10.062 |pmid=24239710 |bibcode=2014AcSpA.121..147Z |issn=1386-1425}}</ref> Rhodamine 123 is used in biochemistry to inhibit [[mitochondrion]] function. Rhodamine 123 appears to bind to the mitochondrial membranes and inhibit transport processes, especially the [[electron transport chain]], thus slowing down [[cellular respiration]]. It is a substrate of [[P-glycoprotein]] (Pgp), which is usually overexpressed in cancer cells. Recent reports indicate that rhodamine 123 may also be a substrate of multidrug resistance-associated protein (MRP), or more specifically, [[MRP1]].<ref>{{Cite journal |last1=Johnson |first1=L V |last2=Walsh |first2=M L |last3=Chen |first3=L B |date=February 1980 |title=Localization of mitochondria in living cells with rhodamine 123. |journal=Proceedings of the National Academy of Sciences |language=en |volume=77 |issue=2 |pages=990–994 |doi=10.1073/pnas.77.2.990 |doi-access=free |issn=0027-8424 |pmc=348409 |pmid=6965798|bibcode=1980PNAS...77..990J }}</ref>

There are many rhodamine derivatives used for imaging purposes, for example Carboxytetramethylrhodamine (TAMRA),<ref>{{Cite journal |last1=Hendrickson |first1=W. A. |last2=Ward |first2=K. B. |date=1975-10-27 |title=Atomic models for the polypeptide backbones of myohemerythrin and hemerythrin |url=https://pubmed.ncbi.nlm.nih.gov/5 |journal=Biochemical and Biophysical Research Communications |volume=66 |issue=4 |pages=1349–1356 |doi=10.1016/0006-291x(75)90508-2 |issn=1090-2104 |pmid=5}}</ref> tetramethylrhodamine (TMR) and its isothiocyanate derivative (TRITC) and, [[sulforhodamine 101]] (and its sulfonyl chloride form [[Texas Red]]) and Rhodamine Red. TRITC is the base rhodamine molecule functionalized with an [[isothiocyanate]] group (−N=C=S), replacing a [[hydrogen]] atom on the bottom ring of the structure. This derivative is reactive towards [[amine]] groups on proteins inside cells. A [[succinimidyl-ester]] functional group attached to the rhodamine core, creating NHS-rhodamine, forms another common amine-reactive derivative.

Other derivatives of rhodamine include newer fluorophores such as [[Alexa (fluor)|Alexa 546, Alexa 633]], [[DyLight Fluor|DyLight 550 and DyLight 633]], [[HiLyte fluor 555 HiLyte 594]], [[Janelia Dyes JF549 and JF669]] have been tailored for various chemical and biological applications where higher [[Photobleaching|photostability]], increased brightness, different spectral characteristics, or different attachment groups are needed.