Rhodamine
Encyclopedia
Rhodamine is a family of related chemical compounds, fluorone
dyes. Examples are Rhodamine 6G and Rhodamine B. They are used as a dye
and as a dye laser
gain medium. They are 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 fluorometer
s. Rhodamine dyes are used extensively in biotechnology applications such as fluorescence microscopy
, flow cytometry
, fluorescence correlation spectroscopy
and ELISA
.
Rhodamine dyes are generally toxic, and are soluble in water, methanol
and ethanol
.
function. Rhodamine 123 seems to bind to the mitochondrion membranes and inhibit transport processes, especially the electron transport chain, thus slowing down inner respiration. It is a substrate of P-glycoprotein
(Pgp), which is usually overexpressed in cancer cells. Recent reports indicate that rhodamine 123 may be also a substrate of multidrug resistance-associated protein (MRP), or more specifically, MRP1.
(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 546, Alexa 555, Alexa 633
, DyLight 549 and DyLight 633
, have been tailored for various chemical and biological applications where higher photostability
, increased brightness, different spectral characteristics, or different attachment groups are needed.
Fluorone
Fluorone is a heterocyclic chemical compound. It forms the core structure for various chemicals, most notably fluorone dyes, including erythrosine. It is an isomer of xanthone, sometimes referred to as an isoxanthone....
dyes. Examples are Rhodamine 6G and Rhodamine B. They are used as a dye
Dye
A dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber....
and as a dye laser
Dye laser
A dye laser is a laser which uses an organic dye as the lasing medium, usually as a liquid solution. Compared to gases and most solid state lasing media, a dye can usually be used for a much wider range of wavelengths. The wide bandwidth makes them particularly suitable for tunable lasers and...
gain medium. They are often used as a tracer dye within water to determine the rate and direction of flow and transport. Rhodamine dyes fluoresce
Fluorescence
Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation of a different wavelength. It is a form of luminescence. In most cases, emitted light has a longer wavelength, and therefore lower energy, than the absorbed radiation...
and can thus be detected easily and inexpensively with instruments called fluorometer
Fluorometer
A fluorometer or fluorimeter is a device used to measure parameters of fluorescence: its intensity and wavelength distribution of emission spectrum after excitation by a certain spectrum of light. These parameters are used to identify the presence and the amount of specific molecules in a medium...
s. Rhodamine dyes are used extensively in biotechnology applications such as fluorescence microscopy
Fluorescence microscope
A fluorescence microscope is an optical microscope used to study properties of organic or inorganic substances using the phenomena of fluorescence and phosphorescence instead of, or in addition to, reflection and absorption...
, flow cytometry
Flow cytometry
Flow cytometry is a technique for counting and examining microscopic particles, such as cells and chromosomes, by suspending them in a stream of fluid and passing them by an electronic detection apparatus. It allows simultaneous multiparametric analysis of the physical and/or chemical...
, fluorescence correlation spectroscopy
Fluorescence correlation spectroscopy
Fluorescence correlation spectroscopy is a correlation analysis of fluctuation of the fluorescence intensity. The analysis provides parameters of the physics under the fluctuations. One of the interesting applications of this is an analysis of the concentration fluctuations of fluorescent...
and ELISA
ELISA
Enzyme-linked immunosorbent assay , is a popular format of a "wet-lab" type analytic biochemistry assay that uses one sub-type of heterogeneous, solid-phase enzyme immunoassay to detect the presence of a substance in a liquid sample."Wet lab" analytic biochemistry assays involves detection of an...
.
Rhodamine dyes are generally toxic, and are soluble in water, methanol
Methanol
Methanol, also known as methyl alcohol, wood alcohol, wood naphtha or wood spirits, is a chemical with the formula CH3OH . It is the simplest alcohol, and is a light, volatile, colorless, flammable liquid with a distinctive odor very similar to, but slightly sweeter than, ethanol...
and ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...
.
Rhodamine 123
The laser dye rhodamine 123 is also used in biochemistry to inhibit mitochondrionMitochondrion
In cell biology, a mitochondrion is a membrane-enclosed organelle found in most eukaryotic cells. These organelles range from 0.5 to 1.0 micrometers in diameter...
function. Rhodamine 123 seems to bind to the mitochondrion membranes and inhibit transport processes, especially the electron transport chain, thus slowing down inner respiration. It is a substrate of P-glycoprotein
P-glycoprotein
P-glycoprotein 1 also known as multidrug resistance protein 1 or ATP-binding cassette sub-family B member 1 or cluster of differentiation 243 is a glycoprotein that in humans is encoded by the ABCB1 gene...
(Pgp), which is usually overexpressed in cancer cells. Recent reports indicate that rhodamine 123 may be also a substrate of multidrug resistance-associated protein (MRP), or more specifically, MRP1.
Other rhodamine derivatives
There are many rhodamine derivatives used for imaging purposes, for example Carboxytetramethylrhodamine (TAMRA), tetramethylrhodamine (TMR) and its isothiocyanate derivative (TRITC) and, sulforhodamine 101Sulforhodamine 101
Sulforhodamine 101 is a red fluorescent dye. In neurophysiological experiments which comprise calcium imaging methods, it can be used for a counterstaining of astrocytes to be able to analyze data from neurons separately....
(and its sulfonyl chloride form Texas Red
Texas Red
Texas Red or sulforhodamine 101 acid chloride is a red fluorescent dye, used in histology for staining cell specimens, for sorting cells with fluorescent-activated cell sorting machines, in fluorescence microscopy applications, and in immunohistochemistry.Texas Red fluoresces at about 615 nm,...
) and Rhodamine Red. TRITC is the base rhodamine molecule functionalized with an isothiocyanate
Isothiocyanate
Isothiocyanate is the chemical group –N=C=S, formed by substituting sulfur for oxygen in the isocyanate group. Many natural isothiocyanates from plants are produced by enzymatic conversion of metabolites called glucosinolates. These natural isothiocyanates, such as allyl isothiocyanate, are also...
group (-N=C=S), replacing a hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
atom on the bottom ring of the structure. This derivative is reactive towards amine
Amine
Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...
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 546, Alexa 555, Alexa 633
Alexa (fluor)
The Alexa Fluor family of fluorescent dyes is produced by Molecular Probes, a subsidiary of Invitrogen. Alexa Fluor dyes are typically used as cell and tissue labels in fluorescence microscopy and cell biology....
, DyLight 549 and DyLight 633
DyLight Fluor
The DyLight Fluor family of fluorescent dyes are produced by Dyomics in collaboration with Thermo Fisher Scientific. DyLight dyes are typically used in biotechnology and research applications as biomolecule, cell and tissue labels for fluorescence microscopy, cell biology or molecular...
, have been tailored for various chemical and biological applications where higher photostability
Photobleaching
Photobleaching is the photochemical destruction of a fluorophore. In microscopy, photobleaching may complicate the observation of fluorescent molecules, since they will eventually be destroyed by the light exposure necessary to stimulate them into fluorescing...
, increased brightness, different spectral characteristics, or different attachment groups are needed.
External links
- Absorption and Emission Spectra of Rhodamine B
- Absorption and Emission Spectra of Rhodamine 6G
- Absorption and Emission Spectra of Rhodamine 123
- Berlier et al. 2003 J. Histochem Cytochem refers to Alexa 633 as a rhodamine derivative.