Fluorescein


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Related to Fluorescein: fluorescein isothiocyanate, Fluorescein sodium

fluorescein

[‚flu̇′re·sē·ən]
(organic chemistry)
C20H12O5 A yellowish to red powder, melts and decomposes at 290°C, insoluble in water, benzene, and chloroform, soluble in glacial acetic acid, boiling alcohol, ether, dilute acids, and dilute alkali; used in medicine, in oceanography as a marker in sea water, and in textiles to dye silk and wool.

Fluorescein

 

a dye; yellow crystals. Fluorescein is poorly soluble in water; it dissolves better in alcohols and dilute alkalies. Decomposition occurs at the melting point, 314°–316°C. In aqueous solutions, fluorescein exists as a 1:1 mixture of the benzoid (I) and quinoid forms and has a strong yellow-green fluorescence (hence the name). Its structural form is

Fluorescein belongs to a group of triarylmethane (xanthene) dyes. It colors silk and wool yellow but is not used in the textile industry because of poor colorfastness. It is used to trace the course of underground waters. Its disodium salt (uranine) is a component of fluorescing mixtures, and its isothiocyanate derivatives are used as biological stains for identifying antigens and antibodies. Some halogen-substituted fluoresceins, such as eosins, also have practical value.

Fluorescein is produced by the condensation of phthalic anhydride with resorcinol.

References in periodicals archive ?
b) FP, forward primer; RP, reverse primer; S, sensor; A, anchor; P, phosphorylated; X, fluorescein.
Figure 2 shows the wavelength dependence of the relative absorption of fluorescein in a pH 9 solution.
Fluorescein is a synthetic pH and concentration-dependent fluorescent organic compound, with peak absorption at 495nm (blue light) and emission at 520nm (green light) in water.
Each probe was designed so that a fluorescein molecule, conjugated to a terminal deoxycytosine, would approximate two to three G residues on annealing to its complementary target.
In the near future, we hope to offer an aqueous solution of fluorescein as an SRM [TM].
Crucially, the Optical Confederation insurance bodies--the AOP, ABDO and FODO have all agreed to continue to cover and defend members, who use CE-marked fluorescein strips in the normal way.
Upon clinical diagnosis, patients underwent further testing of visual fields (Humphrey automated visual field analyzer [HVF], Amsler charting, and fundal fluorescein angiography [FA]), and measurement of central macular thickness with optical coherence tomography (OCT3, Zeiss, Gottingen, Germany).
The guidance, which was issued by the Confederation on behalf of its clinical consensus panel last week (September 23), states that the use of paper-impregnated fluorescein strips, which have been CE marked as medical devices, pose minimal risk.
For each experiment, two signal probes were used, one labeled with fluorescein and the other labeled with TAMRA (Table 2).
This new product detects previously unrecognized structures, combining high resolution cross-sectional images of the retina with any of four imaging modalities: autofluorescence, infrared, fluorescein angiography, or ICG angiography.
This VRICS is designed to encourage practitioners to revise RGP fluorescein patterns and any changes that need to be made to an RGP fit as a result of those patterns.
The conjugates used were goat antihuman IgG, IgM, and IgA conjugated to fluorescein isothiocyanate (Organon Teknika-Cappel, Turnhout, Belgium).