fluorescein

American  

[floo-res-ee-in, flaw-, floh-] / flʊˈrɛs i ɪn, flɔ-, floʊ- /

Or fluoresceine

noun

Chemistry.

1. an orange-red, crystalline, water-insoluble solid, C 20 H 12 O 5 , that in alkaline solutions produces an orange color and an intense green fluorescence: used to trace subterranean waters and in dyes.

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fluorescein British  

/ ˌflʊəˈrɛsɪɪn /

noun

1. 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

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fluorescein Scientific  

/ fl-rĕs′ē-ĭn,flô- /

1. 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: C ₂₀ H ₁₂ O ₅ .

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Etymology

Origin of fluorescein

First recorded in 1875–80; fluoresce + -in ²

Example Sentences

On Monday, the authorities had an answer: Test samples of the water confirmed that the canal’s bright new hue was caused by fluorescein, a chemical often used find leaks during underwater construction.

From New York Times • May 30, 2023

The fluorescein that produces the green coloration can be bought online.

From Washington Times • May 30, 2023

Even before tests confirmed fluorescein was in the water, officials believed the chemical was causing the abnormal hue based on similar episodes in the past, the environmental agency said in a statement on Sunday.

From New York Times • May 30, 2023

Figure 30.32 shows a commonly used fluorescent dye called fluorescein.

From Textbooks • Aug. 12, 2015

By repeating this process two or three times, the fluorescein may be obtained in a very pure condition.

From Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 5 "Fleury, Claude" to "Foraker" by Various