Method for the purification of capsular polysaccharides

A method for purification of capsular polysaccharides, wherein the said method comprises steps of:

• a. culturing the bacterial cells in standard growth conditions to obtain a fermentation broth:
• b. lysing the bacterial cells in fermentation broth obtained in step (a) to obtain a bacterial cell lysate comprising capsular polysaccharide, protein, nucleic acids, cell wall components and other impurities:
• c. subjecting the bacterial cell lysate from step (b) to sizing using homogenizer to obtain a sized crude capsular polysaccharide solution;
• d. passing the sized crude capsular polysaccharide obtained in step (c), through a reinforced cellulose membrane having quaternary ammonium as ligand;
• and
• e. contacting the solution obtained after passing through the reinforced cellulose membrane having quaternary ammonium, in step (d), with silicon dioxide (SiO2) and isolating the capsular polysaccharide in a pure form.