Phycocyanin--a major phycobiliprotein constitutively produced by many 
cyanobacteria--holds several promising applications in diagnostics, biomedical 
research, and therapeutics. This paper discusses a novel rapid method for the 
purification of cyanobacterial phycocyanin (C-PC) from Phormidium fragile using 
hydrophobic interaction chromatography. The protein was extracted and 
concentrated by grinding under liquid nitrogen and ammonium sulfate 
fractionation. C-PC was purified by single step hydrophobic interaction 
chromatography. Purified phycocyanin showed absorbance maximum (lambda(max)) at 
624 nm. The criterion of purity (R) achieved was 4.52. Phycocyanin to 
phycoerythrin and phycocyanin to allophycocyanin purity ratio were 3.85 and 
7.49, respectively. The purified protein showed a pI of 5.2 and has two subunits 
with molecular mass of 19 and 20 kDa each, corresponding to its highly reported 
alpha and beta subunits. The subunits of phycocyanin were confirmed by their 
bilin fluorescence using zinc assisted fluorescence enhancement technique. 
Intact C-PC was of 125 kDa as determined by HPLC, suggested the (alphabeta)(3) 
subunit assembly. Results obtained by this method in terms of purity, recovery, 
process time, simplicity, and efficacy are much better than previous 
methodologies. Purified phycocyanin was further scrutinized for its antioxidant 
capacity and judged against five non-enzymatic antioxidants by FRAP assay.