PerCP (Peridinin-chlorophyll-protein complex) is isolated from Dinophyceae sp. It has an extremely high extinction coefficient, a high quantum efficiency and a large Stokes shift. It is well excited with the Argon laser at 488 nm with its maximum emission peak at 677nm. PerCP protein is commonly used for fluorescent immunolabeling, particularly in applications involving fluorescent-activated cell sorting (FACS). Its cyanine tandem conjugates (such as PerCP-Cy5.5 developed by BD) can be excited with a standard 488 nm laser and emits in the far red at a longer wavelength for multicolor flow cytometric analysis of cells.