Biotin-XX, Free Acid (6- ((6- ((Biotinoyl)

Biotin-XX free acid (6- ((6- ((Biotinoyl) amino) hexanoyl) amino) hexanoic acid) can be easily converted to the mixed anhydride form, which is more reactive than the succinimidyl ester and thus can be used to react with aromatic amines or sterically hindered amines. A detailed protocol for making mixed anhydrides is provided upon request with purchase of the product.