Also found in: Dictionary, Thesaurus, Medical, Wikipedia.


(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.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



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.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
All patients were operated by a single surgeon and IOP was measured after first post-operative day, and after intervals of first week, second week, one month and forty days using applanation tonometry (AT) and fluorescein dye.
After fluorescein is injected into the antecubital vein, the time it takes to reach the eye depends upon the patient's arm-to-retina circulation time.
The mean value of fluorescein test was 8.4 ([+ or -]1.88), ranging from 5 to 12 in the control group and 6.6 ([+ or -]1.42), ranging from 5 to 10 in the group with stages III and IV of blepharospasm, yielding a statistically significant difference (Mann Whitney test, p<0.001) (Fig.
The inner primers were designed with a digoxigenin or a fluorescein moiety at their 51 end; thus, the short products were labelled with digoxigenin for the SJNNV genotype or fluorescein for the RGNNV genotype.
Fluorescein angiography demonstrated delayed filling and emptying of this artery (Figure 1(B)).
Subsequent endoscopic evaluation of the nasopharynx and oropharynx revealed significant pooling of fluorescein, but both openings to the eustachian tubes were normal.
The primary purpose of this study was to investigate whether fluorescein leakage within recent subretinal hemorrhage in pathologic myopia is suggestive of CNV.
Four different regimens were used for intraoperative ureteral evaluation: 1) oral phenazopyridine 200 mg, 2) intravenous sodium fluorescein 25 mg, 3) mannitol bladder distention, and 4) normal saline bladder distention.
FFA: After the absence of obvious contraindications and negative fluorescein sodium skin test were determined by general examination for blood pressure, pulse, electrocardiogram and biochemistry, 5 mL of fluorescein sodium (20%) was intravenously injected for 5 s.
Keywords: Cyclosporine, Dry eye disease, Fluorescein staining, International task force (ITF) guidelines, Keratoconjuctivitis sicca (KCS), Schirmer test, Tear break up time (BUT).
FL is an easily available and biosafe fluorescein dye with a peak excitation at 465 to 490 nm and emission between 500 and 550 nm and has been used extensively and safely for many years especially in ophthalmology [7, 8].