Peridinin
# Peridinin

Peridinin is a light-harvesting apocarotenoid, a pigment associated with chlorophyll and found in the peridinin-chlorophyll-protein (PCP) light-harvesting complex in dinoflagellates, best studied in Amphidinium carterae.

## Biological significance

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.

## Spectral characteristics

* Absorption maximum: 483 nm
* Emission maximum: 676 nm
* Extinction coefficient (ε): 1.96 x $10^6M^{−1}cm^{−1}$
* $A_{483}/A_{280}$ ≥ 4.6

## Applications

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.

