Every fluorophore has a unique excitation and emission profile which is usually displayed on a spectral viewer, or spectral graph. The combination of the excitation and emission profiles is the fluorophore’s spectral profile. Every fluorophore has a peak excitation wavelength (the wavelength at optimal excitation) and a peak emission wavelength (the wavelength of optimal detection). Each fluorophore will also have a much larger range of excitation and emission wavelengths at reduced optimization. This “curve” is what is displayed on a spectral viewer.
The spectral profile of a fluorophore is used to determine the excitation and detection efficiency at any given wavelength. The spectral profile aids in panel design and selecting optimal fluorophores for a given instrument. The spectral profile can also help in determining compensation considerations.
There are numerous resources available to view the spectral profiles of various fluorophores. Some of the most common are listed below. Tools like Fluorish’s Panel Builder assist in optimal fluorophore selection utilizing a database of the spectral profiles and algorithms for fluorophore assignment to any specified instrument configuration.
http://www.mcb.arizona.edu/ipc/fret/
http://www.bdbiosciences.com/research/multicolor/spectrum_viewer/
http://www.ebioscience.com/resources/fluorplan-spectra-viewer.htm