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.

---

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

---

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 .

---

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 chemical cause of the color change was found to be fluorescein, which is used professionally to trace water.

From Washington Times • May 30, 2023

Figure 30.32 shows a commonly used fluorescent dye called fluorescein.

From Textbooks • Aug. 12, 2015

The eye doctor trained her scope on the patient’s retina and then injected a dye called fluorescein.

From New York Times • Jun. 5, 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