Biochemical research
Health care applications
Air Sea Rescue
A fluorophore in microscopy.
Uses in river systems
In a type of dye laser as a gain medium.
Oilfield application
In forensics and serology to detect latent blood stains.
In yellow smoke devices.

Fluorescein is a fluorescent dye which is used in a number of different applications in the sciences and medicine. In pure state, fluorescein is a red or orange powder which is dissolved in alkaline solutions to make up a yellow solution which will glow green. In addition to using straight fluorescein, researchers also work with various derivatives of the compound which are designed to conjugate to specific types of molecules and perform other functions.

In medicine, this compound has a broad range of uses. Ophthalmologists use it in eye exams, staining the eye with the dye to look for signs of tears in the cornea, and they can also use it for fluorescein angiography of the retina, using the dye to look for leaks inside the blood vessels in the eye. The chemical can also be used as a tracer in other areas of the body, and it is utilized in microscopy and as a stain. In addition, fluorescein derivatives are used in the lab to identify compounds in fluid samples, with the chemical attaching to specific proteins to act as a flag.