Problem to be solved: to provide a method for removing impurities from a cell lysate of bacteria producing polysaccharides, especially for purification of bacterial polysaccharides.Solution: a solution containing a bacterial polysaccharide such as a polysaccharide and a capsular polysaccharide, which contains an agglutination step, which uses an agglutination agent such as mirage, is used in an acidic pH condition, and the suspension after coagulation is melted by centrifugation, and is subjected to deep filtration, and the filtrate is subjected to ultrafiltration and dialysis filtration Further, the purification method for sterilization filtration after homogenization by sizing.Diagram【課題】細菌多糖類を精製するため、特に、多糖類を産生する細菌の細胞溶解物から不純物を除去するための方法の提供。【解決手段】夾雑物と莢膜多糖等の細菌多糖を含む溶液に対して、ミョウバン等の凝集剤を酸性ｐＨ条件下で用いる凝集ステップを含む精製方法であり、凝集の後の懸濁液を遠心分離等で清澄化し、深層濾過を行い、その濾液を限外濾過及び透析濾過によってさらに処理し、サイジングによってホモジナイズ後に滅菌濾過する精製方法。【選択図】図１
