Is fluorescein dye radioactive?

Fluorescein dye is not radioactive. It is a synthetic organic compound that is widely used as a fluorescent tracer for many applications, including medical diagnostics. The compound absorbs light and subsequently emits light at a longer wavelength, which is what provides the fluorescent effect.

When used in medical diagnostics, such as in a fluorescein angiography, the dye is injected into the bloodstream. The dye then circulates and allows for the visualization of blood flow, especially in the back of the eye on the retina. The fluorescence can be captured by special cameras and analyzed by eye-care professionals to diagnose and monitor conditions like diabetic retinopathy, age-related macular degeneration, and vascular occlusions.

The misconception about its radioactivity might stem from its association with diagnostic procedures, some of which involve radioactive tracers or imaging techniques that require ionizing radiation, such as X-rays or CT scans. However, the mechanisms of fluorescence involve the release of photons after excitation by a light source, such as a laser, and do not involve radioactivity or the emission of ionizing radiation.

Therefore, fluorescein is considered safe for use in diagnostic testing from a radioactivity standpoint, although it can have some side effects unrelated to radiation, such as nausea, vomiting, and allergic reactions in rare cases.