57 protein spots out of about 1000 detectable spots on the 2 - d gels were indentified by the following two methods : l ) n ~ terminal edman degradation microsequencing after the protein spots were electro - transferred to pvdf membrane . 2 ) maldi - tof - ms peptide fingerprint analysis of the protein spots and protein database searching . the 2d protein maps of the rice spikelet during the sterile and fertile stages were compared 二是通过原位酶解,抽提蛋白质片段进行maldi - tof质谱分析,利用肽质量指纹图数据在数据库中进行检索,在双向电泳凝胶上取了57个点进行分析,有34个蛋白质点在数据库得到归属鉴定。