Polysaccharides are mainly present in the cell wall of C. sinensis,
and are within the cytoplasm as a structural component.
Generally, extraction treatment with different solvents, such as
hot water, alkali solution etc., enables isolation and purification
of the polysaccharide according to their different solubility in
water and organic solvents, or based on their different ionic
properties and molecular weight distributions. Other techniques
have also been used such as organic solvent precipitation,
fractional precipitation, acidic precipitation with acetic acid,
adsorption resin, ultra-filtration, dialysis, ion-exchange chromatography, gel filtration, and affinity chromatography method etc.