Allophycocyanin

Allophycocyanin is a pigment that is involved in the photosynthesis of the red algae and cyanobacteria and is one of the phycobilins.

This protein has a molecular mass of approximately 80 kDa. Coupled to an antibody, it is one of the brightest fluorescent dyes used for FACS analysis and is also used the fluorescence- microscopic detection of specific antigens. It is excited by a He-Ne laser at 633 nm and emits light of wavelength 680 nm