Definition of "fluorescein" [fluo•res•ce•in]

• An orange-red compound, C20H12O5, that exhibits intense fluorescence in alkaline solution and is used in medicine for diagnostic purposes, in oceanography as a tracer, and as a textile dye. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Most of the time, the diagnosis can be made based on a clinical exam, although a test called fluorescein angiography is often performed to assess the severity."
• "Semrock has released four optical filter sets for fluorescence imaging that enable increased brightness or enhanced contrast when imaging labels fluorescein"
• "They used a technique known as fluorescein angiography, which involves injecting a special dye into the arm intravenously and photographing its passage through the blood vessels of the retina."