Fluorescein is an organic compound and dye. It is available as a dark orange/red powder slightly soluble in water and alcohol. It is widely used as a fluorescent tracer for many applications.

The application of fluorescein also extends to bioimaging of whole anatomic structures and even further to cellular components in immunohistological staining.

Administering Fluorescein orally greatly reduces the risk of allergic reactions. No serious reactions have been reported but mild reactions may include itching or a mild skin rash.

Fluorescein is an organic compound that has wide use as a synthetic coloring agent. ... Fluorescein appears as yellow amorphous solid or orange-red crystals. Latter have greenish-yellow fluorescence by reflected light. Insoluble in water. Soluble in dilute aqueous bases.

FLUORESCEIN