目的 建立一种应用脱氧胆酸钠沉淀和离子交换色谱技术纯化5型肺炎球菌荚膜多糖的方法。方法  5型肺炎球菌发酵液经离心、超滤、脱氧胆酸钠沉淀处理后，再经过Capto Q离子交换层析，得到精制多糖原液。依据中国药典2020年版三部的相关制检规程对精制多糖原液进行检定分析。结果  发酵液中蛋白质和核酸杂质去除率分别达到97.0%和99.9%以上，糖醛酸含量不低于18.4%，氨基己糖含量不低于22.7%，各项指标均符合中国药典标准；且多糖收率达到60.0%以上。结论  建立的5型肺炎球菌荚膜多糖纯化工艺可替代使用乙醇或苯酚的工艺，且操作步骤简便，具有很好的规模化应用前景。

Objective  To develop a method for purification of capsular polysaccharide from Streptococcus pneumoniae serotype 5 by protein precipitation with sodium deoxycholate (DOC) and ion exchange chromatography. Methods  Streptococcus pneumoniae serotype 5 fermentation broth was treated by centrifugation, ultrafiltration and DOC precipitation, and then purified with Capto Q ion exchange chromatography to obtain the refined polysaccharide stock. The indexes of the purified polysaccharide bulk were analyzed according to the requirements of Chinese pharmacopoeia. Results The removal rates of protein and nucleic acid in fermentation broth were 97. 0% and 99.9%. respectively. The contents of uronic acid and hexosamine in the purified polysaccharide were no less than18. 4% and 22. 7%. All the quality indicators meet the requirements of Chinese pharmacopoeia. The yield of polysaccharide was more than 60. 0%. Conclusion  An purification process of Streptococcus pneumoniae capsular polysaccharide is established, which can take place of methods using ethanol or phenol with good operability and a good prospect of industrial application.