fluorescein

or flu·o·res·ce·ine

[ floo-res-ee-in, flaw-, floh- ]

/ flʊˈrɛs i ɪn, flɔ-, floʊ- /

noun Chemistry.

an orange-red, crystalline, water-insoluble solid, C20H12O5, that in alkaline solutions produces an orange color and an intense green fluorescence: used to trace subterranean waters and in dyes.

Nearby words

fluor, fluor-, fluorapatite, fluorene, fluoresce, fluorescein, fluorescence, fluorescence-activated cell sorter, fluorescent, fluorescent antibody technique, fluorescent antinuclear antibody test

Origin of fluorescein

First recorded in 1875–80; fluoresce + -in²

Also called resorcinolphthalein.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for fluorescein

By repeating this process two or three times, the fluorescein may be obtained in a very pure condition.
Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 5|Various
Fluorescein is readily nitrated, yielding a di- or tetra-nitro compound according to conditions.
Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 5|Various
If we fill a glass container with a fluorescein solution and look at it by reflected light it appears green.
Astounding Stories of Super-Science January 1930|Victor Rousseau

British Dictionary definitions for fluorescein

fluorescein

fluoresceine

/ (ˌflʊəˈrɛsɪɪn) /

noun

an orange-red crystalline compound that in aqueous solution exhibits a greenish-yellow fluorescence in reflected light and is reddish-orange in transmitted light: used as a marker in sea water and as an indicator. Formula: C 20 H 12 O 5

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for fluorescein

fluorescein

[ flu-rĕs′ē-ĭn, flô- ]

n.

An orange-red compound that exhibits intense fluorescence in alkaline solution and is used in ophthalmology to reveal corneal lesions.

Science definitions for fluorescein

fluorescein

[ flu-rĕs′ē-ĭn, flô- ]

An orange-red crystalline compound that exhibits intense fluorescence in alkaline solution. It is used in medicine for diagnostic purposes, in oceanography as a tracer, and as a textile dye. Chemical formula: C20H12O5.