Fluorescein

Fluorescein is a synthetic dye that absorbs blue or ultraviolet light and emits yellow-green fluorescence. Its bright signal and water-soluble derivatives make it useful in imaging, tracing, and diagnostic tests.

Fluorescence: Fluorescence is light emission from a substance after it absorbs light or other electromagnetic radiation. Fluorescein’s yellow-green glow is an instance of this light-emission process.
Fluorescein angiography: A retinal imaging procedure that uses injected fluorescein dye to reveal blood flow and leakage in retinal vessels. Injected dye makes retinal circulation visible in this diagnostic imaging method.
Adolf von Baeyer: A German chemist who synthesized fluorescein in 1871 and later received the Nobel Prize in Chemistry. Baeyer’s synthesis established fluorescein as a distinct dye.
Rhodamine: A family of fluorescent dyes that commonly emit red or orange light and are used as labels and probes. Rhodamine offers longer-wavelength emission than fluorescein for separating signals.
Fluorescein dianion: The negatively charged form of fluorescein that predominates in alkaline aqueous solutions and fluoresces strongly. This molecular form accounts for much of fluorescein’s bright signal in alkaline fluids.
Fluorescein staining: A diagnostic technique in which fluorescein highlights damaged or disrupted epithelial surfaces, especially on the cornea. The dye marks corneal defects that are difficult to see under ordinary illumination.
Xanthene dyes: A family of synthetic dyes built around a xanthene framework, many of which are intensely colored or fluorescent. Fluorescein belongs to this chemical family.
Tetramethylrhodamine: A red-emitting fluorescent dye used to label biomolecules and visualize them in microscopy. Its red signal can be distinguished from fluorescein’s green emission.
Fluorescein lactone: A closed-ring form of fluorescein that is weakly colored and largely nonfluorescent. The equilibrium between this form and open fluorescent forms helps explain pH-dependent color.
Fluorescence microscopy: Microscopy that detects light emitted by fluorescent molecules excited by a selected wavelength. Fluorescein is a widely used label and probe in this imaging technique.

Linked from 6 pages