6-Carboxyfluorescein (6-FAM) is a

fluorescent dye A fluorophore (or fluorochrome, similarly to a chromophore) is a fluorescent chemical compound that can re-emit light upon light excitation. Fluorophores typically contain several combined aromatic groups, or planar or cyclic molecules with se ...

with an absorption wavelength of 495 nm and an emission wavelength of 517 nm. A carboxyfluorescein molecule is a

fluorescein Fluorescein is an organic compound and dye based on the xanthene tricyclic structural motif, formally belonging to triarylmethine dyes family. It is available as a dark orange/red powder slightly soluble in water and alcohol. It is widely used ...

molecule with a

carboxyl In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is or , with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic ...

group added. They are commonly used as a tracer agents. It is used in the sequencing of nucleic acids and in the labeling of nucleotides. Commercially available FAM is a mixture of two isomers, 5-FAM and 6-FAM, and the correct name is 5(6)-carboxyfluorescein. The dyes are membrane-impermeant and can be loaded into cells by

microinjection Microinjection is the use of a glass micropipette to inject a liquid substance at a microscopic or borderline macroscopic level. The target is often a living cell but may also include intercellular space. Microinjection is a simple mechanical pro ...

or scrape loading. It can be incorporated into

liposomes A liposome is a small artificial Vesicle (biology and chemistry), vesicle, spherical in shape, having at least one lipid bilayer. Due to their hydrophobicity and/or hydrophilicity, biocompatibility, particle size and many other properties, lipo ...

, and allows for the tracking of liposomes as they pass through the body. In addition, carboxyfluorescein has been used to track division of cells. In vascular plants, 5(6)-carboxyfluorescein can be used as a symplastic tracer. It is able to move through the

phloem Phloem (, ) is the living biological tissue, tissue in vascular plants that transports the soluble organic compounds made during photosynthesis and known as ''photosynthates'', in particular the sugar sucrose, to the rest of the plant. This tran ...

due to its structural similarity to sucrose. It is typically loaded into the leaves in order to gain access to the phloem. This can be done by scraping, cutting, or weakening the leaf’s cuticle with an herbicide. Popular derivatives for cell tracing purposes are carboxyfluorescein diacetate succinimidyl ester (CFDA-SE) and

carboxyfluorescein succinimidyl ester Carboxyfluorescein succinimidyl ester (CFSE) is a fluorescent cell staining dye. CFSE is cell permeable and covalently couples, via its succinimidyl group, to intracellular molecules, notably, to intracellular lysine residues and other amine sou ...

(CFSE).

References

{{DEFAULTSORT:Carboxyfluorescein6 Fluorone dyes Benzoic acids Dicarboxylic acids Triarylmethane dyes

See also

References