fluorescein

noun

fluo·​res·​ce·​in flu̇-ˈre-sē-ən 

flȯ-

: a yellow or red crystalline dye C₂₀H₁₂O₅ with a bright yellow-green fluorescence in alkaline solution

Examples of fluorescein in a Sentence

Recent Examples on the Web

The analysis of the water samples revealed the presence of a non-toxic tinting agent called fluorescein, which is most commonly used in eye tests. —Ananya Bhattacharya, Quartz, 30 May 2023

Officials took samples at different depths in the water to determine how much fluorescein sunk to the bottom of the canal. —Sarah Kuta, Smithsonian Magazine, 31 May 2023

Testing showed the presence of fluorescein, an environmentally harmless dye that can be used to locate blood at crime scenes and diagnose eye injuries. —Sarah Kuta, Smithsonian Magazine, 31 May 2023

Researchers dumped a dye, fluorescein, into the wells and monitored the marine waters along the beaches. —Warren Cornwall, Science | AAAS, 23 Apr. 2020

The polyacrylate was then bathed in molecules of fluorescein, an orange dye with a yellow-green fluorescence that's commonly used as a scientific marker. —David Grossman, Popular Mechanics, 18 Dec. 2018

With the fluorescein in place, scientists then add an acid that hinders the negative charges in the polyacrylate gel. —David Grossman, Popular Mechanics, 18 Dec. 2018

Our doctor placed yellow drops containing fluorescein sodium in his eye. —Dan Olson, WIRED, 29 Sep. 2008

Word History

First Known Use

1871, in the meaning defined above

Medical Definition

fluorescein

noun

flu·​o·​res·​ce·​in -ˈes-ē-ən 

: a yellow or red crystalline dye C₂₀H₁₂O₅ with a bright yellow-green fluorescence in alkaline solution that is used as the sodium salt as an aid in diagnosis (as of lesions and foreign bodies in the cornea or of brain tumors)