Hello. I am having trouble dissolving chitosan in 50mM MES buffer (pH 6.0). I am trying to dissolve at a concentration of 5mg/mL. I tried to stir for 2 days at 50°C but could not dissolve a large portion of the solid. Is there any technique I am missing here? Does sonication help dissolving chitosan? I would really appreciate your time and advice. Thank you very much.