Table 2.

Summary of information provided by the certificate of analysis for phycobiliproteins (ProZyme, Inc.)

Phycobiliprotein	Code	MW (kDa)	Protein subunits	Absmax (nm)	Emmax (nm)	Purity		Extinc. coeff. E 1%λ,max	Origin
						Aλmax/A280 a	A620/A566 b
C-Phycocyanin	PB11	232	(αβ)6	620	647	4.68	n.a.	70	Spirulina platensis
R-Phycoerythrin	PB31	240	(αβ)6γ	496–566	576	5.61	<0.005	82	Red algae
Allophycocyanin	PB20	104	(αβ)3	648–652	660	5.3	n.a.	73	Spirulina platensis

n.a. not available

^aIndicative of the purity of the preparation with respect to most forms of contaminating protein. Absorbance at 280 nm in these preparations is primarily due to aromatic amino acids, and this is roughly proportional to the overall concentration of protein in solution, including C-PC, R-PE, and Allo-PC. The respective absorbances at 620, 566, and 652 nm reflect only concentration

^bRough indicator of the level of contamination with R-PC