The excitation spectrum and emission spectra (bold line) are shown for the tandem dye Cy7APC. The red-shaded region represents the bandpass filter commonly used to measure Cy7APC fluorescence. Cy7APC is excited by either a dye laser (595-605 nm) or a HeNe laser (633 nm). Depending on the degree of quenching of APC fluorescence by the Cy7, different degrees of compensation will be required with the APC channel (emission at 660 nm). This dye provides a third bright color for dye lasers and a second color for HeNe lasers.

Compare the Cy7APC fluorescence spectra to spectra for several FACS immunofluorescence dyes.