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(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.



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 ?
At the fluorescein angiography (Figure 1 and Figure 2), the arterial stage in the animals treated with sildenafil for 7 and 15 days started more quickly, when compared to the arterial stage prior to treatment, however, a significant difference (P=0.
Fluorescein interference with urinary creatinine and protein measurements.
5 ml of incubation buffer containing fluorescein (10 [mu]M) in the absence and presence of tested agents.
The researchers firstly produced colloidal gold nanoparticles, and then they modified them by using fluorescein isothiocyanate.
Key words: diseases of birds, thermography, fluorescein, angiography, vascular occlusion, wing amputation, avian, flamingo, Phoenicopterus chilensis
Fluorescein angiography still demonstrated the presence of the embolus with a restoration of retinal arteriolar blood flow and regression of macular edema.
Seven of these cases had photodynamic diagnosis (PDD) following intravenous injection of fluorescein.
Key Features: The method involves plaque disclosure with a fluorescein dye followed by a digital image.
So the fluorescein (Wolbeis, 1991) and his derivates are the very used indicators in the case of the chemical optrods wits optical fibres.
Staining with fluorescein should be carried out to exclude herpes simplex.
When used in conjunction with intravenous contrast agents such as fluorescein, acriflavine, and cresyl violet, the microscope allows endoscopists to visualize the abnormal cell growth that is characteristic of cancerous lesions.