The excitation spectrum and emission spectra (bold line) are shown for the tandem dye Cy7PE. The red-shaded region represents the bandpass filter commonly used to measure Cy7PE fluorescence. Cy7PE is excited by an argon laser (tuned to 488 nm). Depending on the degree of quenching of PE fluorescence by the Cy7, different degrees of compensation will be required with the PE channel (emission at 575 nm). Because Cy7 is inefficiently excited by either dye lasers or HeNe lasers, the Cy7PE tandem is useful in conjunction with APC. This dye provides a fourth bright color off of the 488 nm excitation line. It can used in place of Cy5PE when APC is also used on instruments with 488nm and HeNe (633nm) excitation.

Compare the Cy7PE fluorescence spectra to spectra for several FACS immunofluorescence dyes.