Preparation of Low MW Chitosan

Dissolve 0.25 g Chitosan in  25 ml of 72 mM sulfuric acid solution (concentrated: 18.4 M, add 98~100 ul of Concentrated H₂SO₄ to 25 ml H2O-->72 mM) in a 250 ml glass bottle

Autoclave for 30 min.

Cool down on ice

Adjust pH to 7~8 using 30 mL of 150 mM NaOH.

Transfer to a centtrifuge tube, spin, collect pellet. Wash with water until pH is neutral