Given their large range of applications and potential uses, researchers have been trying to find and develop ways to produce and purify phycobiliproteins to meet the growing demand for them.[18] One such phycobiliprotein is C-phycocyanin (C-PC), which is found in spirulina. A limiting factor of C-PC's usage in these applications is its protein stability, given that in its natural form, C-PC is highly sensitive to light and heat when in aqueous solution, due to its photosensitive phycocyanobilin (PCB) chromophore, which also makes it prone to free-radical oxidation. Like other natural food colourants, C-PC is also sensitive to acidic conditions and oxidant exposure.