A, Thylakoid membrane complexes in C. reinhardtii 1690 and Clamydomonas sp. UWO241 were fractionated using Suc density centrifugation. B to E, SDS-PAGE profiles of purified major complexes were Coomassie stained (B and C) and immunoblotted with P-Thr antibodies (D and E). F to I, 77K fluorescence emission spectra of intact thylakoid membranes (F and G) were compared to those of purified fractions of LHCII, PSII, PSI, and the SC in C. reinhardtii 1690 (H) and Clamydomonas sp. UWO241 (I). Chl fluorescence was excited at 436 nm.