Several lines of evidence indicate that allophycocyanin is the previously unidentified "phycochrome" observed in extracts of blue-green algae.Fractions containing phycoerythrin, phycocyanin, and allophycocyanin and exhibiting light-induced absorbance changes were prepared from extracts of Nostoc muscorum and Fremyella diplosiphon by isoelectric focusing. Illumination of such fractions with red ...
