Used in Alcian Blue Method (pH 2.5) for staining weakly acidic sulfated mucosubstances, hyaluronic acid and, sialomucins. See AFIP Manual of Histological Stains Methods, 3rd Ed, Ed. L. Luna: New York McGraw Hill Publications, c. 1968, p. 163. or Lev, R. & Spicer. S.S., J. Histochem Cystochem, 12:309, 1964