The excitation spectrum and emission spectra (bold line) are shown for
Cascade Blue. The red-shaded region represents the bandpass filter commonly
used to measure Cascade Blue fluorescence. While the 351/361 excitation
line from an Argon laser is more commonly-available, the 405 nm line from
a Krypton line provides a considerably brighter dye, for two reasons: the
greater absorption at 405, and the lower autofluorescence of cells excited
Compare the Cascade Blue fluorescence spectra to spectra for several FACS immunofluorescence dyes.