Fluorescent Dye

Fluorescent dye probes, or fluorophores, are compounds that absorb light at a given wavelength and emit light at a higher wavelength, producing fluorescence in various colors. These dyes can be grouped into categories such as organic dyes (e.g., fluorescein, rhodamine, AMCA), biological fluorophores (e.g., green fluorescent protein, phycoerythrin, allophycocyanin) and quantum dots.
Fluorescent probes absorb light at a specific wavelength and emit light of a different, typically longer, wavelength. This process is known as fluorescence emission. Fluorescence is safer to use and does not require radiological controls. Because fluorophores do not overlap, several fluorescent molecules can be used simultaneously.
Fluorescent dyes are often used in the fluorescent labeling of biomolecules and can be smaller or more photostable than fluorescent proteins but cannot be genetically encoded.