Peridinin is an apocarotenoid pigment that some organisms use in photosynthesis. Many photosynthetic dinoflagellates use peridinin, which absorbs blue-green light in the 470-550nm range, outside the range accessible to chlorophyll molecules. The peridinin-chlorophyll-protein complex is a specialized molecular complex consisting of a boat-shaped protein molecule with a large central cavity that contains peridinin, chlorophyll, and lipid molecules, usually in a 4:1 ratio of peridinin to chlorophyll.
Peridinin chlorophyll (PerCP) is commonly used in immunoassays such as fluorescence-activated cell sorting (FACS) and flow cytometry. The fluorophore is covalently linked to proteins or antibodies for use in research applications.