用电泳和分光光度法对桔梗开花盛期不同部位叶子的酯酶与蛋白质进行了研究。结果表明，不同部位叶子的酯酶和蛋白质电泳图谱有所差异。从上部叶子到下部叶子蛋白质含量变化的总趋势是逐渐下降的，中部叶子的蛋白质含量最高。

By means of electrophoresis and spectrophotometry.the esterase and protein in different positions of the leaves of Platycodon grandiflorum during full blooming season were studied.Results showed that the electrophoresis graphs of esterase and protein in leaves at different positions were different.The general changing trend of the content of protein was decreasing gradually from the upper part of the leaf to its lower part,and the content of protein was highest in the middle part of the leaf.