The researchers studied chlorophyll levels in photosystem II proteins using different preparations. They found that oxygen-evolving complexes with CP26 and CP29 bind 42 chlorophyll molecules. Without CP26 and CP29, PSII cores bind 30 chlorophylls, and CP43-less cores bind around 18 chlorophylls. CP47 and CP43 bind 9-12 chlorophylls, and the D1/D2 complex binds 6 chlorophylls. Altogether, CP26 and CP29 bind about 12 chlorophyll molecules.