Purification of C-Phycocyanin from Spirulina platensis by Single-Step Ion-Exchange Chromatography

C-Phycocyanin is a natural blue pigment with many commercial applications in foods, cosmetics, and medicines. In this paper we describe the extraction and purification of C-phycocyanin from the cyanobacterium Spirulina platensis. The procedure is based on adsorption of impurities with chitosan and activated charcoal then one-step ion-exchange chromatography. The dry algal powder was soaked in potassium phosphate buffer for 2 h to furnish crude phycocyanin extract of purity 0.93. The crude extract was then treated with chitosan and activated charcoal for 5 min, which increased the purity to 2.78. After chromatography on DEAE Sephadex A-25, the purity of phycocyanin was improved to 4.3. The identity of the purified phycocyanin was confirmed by sodium dodecyl sulfate–polyacrylamide gel electrophoretic analysis and by spectroscopic measurements (UV–visible spectrophotometry and spectrofluorimetry). Compared with conventional methods, this method was simple, inexpensive, and time-saving.