10 % and 15 % sucrose layers were identified as light harvesting complexes ; 20 % and 30 % sucrose layers were identified as composed of active ps ii particles ; 40 % sucrose layer represented rather pure ps i complex 确定了10和15层带的色素蛋白复合物为捕光色素复合物; 20和30层带的复合物为ps颗粒,具有dcip的光还原活性; 40层带复合物为去除了捕光色素的ps复合物。