Rhodamine 123 is a chemical compound and a dye. It is often used as a

tracer dye Dye tracing is a method of tracking and tracing various Fluid dynamics, flows using dye as a flow tracer when added to a liquid. Dye tracing may be used to analyse the flow of the liquid or the transport of objects within the liquid. Dye tracking m ...

within water to determine the rate and direction of flow and transport. Rhodamine dyes

fluoresce Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, tha ...

and can thus be detected easily and inexpensively with instruments called

fluorometer A fluorometer, fluorimeter or fluormeter is a device used to measure parameters of visible spectrum fluorescence: its intensity and wavelength distribution of emission spectrum after excitation by a certain spectrum of light. These parameters ar ...

s. Rhodamine dyes are used extensively in biotechnology applications such as

fluorescence microscopy A fluorescence microscope is an optical microscope that uses fluorescence instead of, or in addition to, scattering, reflection, and attenuation or absorption, to study the properties of organic or inorganic substances. "Fluorescence microscop ...

flow cytometry Flow cytometry (FC) is a technique used to detect and measure physical and chemical characteristics of a population of cells or particles. In this process, a sample containing cells or particles is suspended in a fluid and injected into the flo ...

fluorescence correlation spectroscopy Fluorescence correlation spectroscopy (FCS) is a statistical analysis, via time correlation, of stationary fluctuations of the fluorescence intensity. Its theoretical underpinning originated from L. Onsager's regression hypothesis. The analysis p ...

and

ELISA The enzyme-linked immunosorbent assay (ELISA) (, ) is a commonly used analytical biochemistry assay, first described by Eva Engvall and Peter Perlmann in 1971. The assay uses a solid-phase type of enzyme immunoassay (EIA) to detect the presence ...

. Rhodamine fluorescence can also be used as a measure of membrane polarization in live cell assays both within mitochondria and with bacteria. This use relies on the fact that rhodamine 123 accumulates in membranes in a manner which is dependent on membrane polarization. The absorption of rhodamine 123 peaks around 505 nm and luminescence is tunable around 560 nm when used as a

laser dye Laser dyes are dyes used as laser medium in a dye laser. Laser dyes include the coumarins and the rhodamines. Coumarin dyes emit in the green region of the spectrum, whereas rhodamine dyes are used for emission in the yellow-red. The color emi ...

. Its luminescence

quantum yield The quantum yield (Φ) of a radiation-induced process is the number of times a specific event occurs per photon absorbed by the system. Applications Fluorescence spectroscopy The fluorescence quantum yield is defined as the ratio of the numb ...

is 0.90.R. F. Kubin and A. N. Fletcher, "Fluorescence quantum yields of some rhodamine dyes.
J. Luminescence 27 (1982) 455
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References

See also