PerCP-Cy5.5 dye is part of the BD blue family of dyes. This tandem fluorochrome is comprised of a fluorescent protein complex (PerCP) with an excitation maximum (Ex Max) of 482 nm and an acceptor dye with an emission maximum (Em Max) at 676 nm. PerCP-Cy5 is designed to be excited by the blue laser (488-nm) and detected using an optical filter centered near 680 nm (e.g., a 695/40 nm bandpass filter). The donor dye can be partially excited by the Violet (405-nm) laser resulting in cross-laser excitation and fluorescence spillover. Please ensure that your instrument’s configurations (lasers and optical filters) are appropriate for this dye.