extinction coefficient

As commonly used in the context of fluorescence, it is a measure of how well a fluorophore absorbs an incident photon. This determines a fluorophore's overall brightness together with its quantum yield.

Synonyms: molar absorption coefficient, mass extinction coefficient, attenuation coefficient

See also: brightness (fluorophore), quantum yield, fluorescence, fluorophore

Learn more:

Imaging Fluorescent Proteins

Filter requirements, photobleaching, objective choice, highlighters, and multicolor imaging.