Sodium meta-Periodate (NaIO₄) is a useful reagent for the oxidation of carbohydrates to aldehydes. Sodium meta-Periodate converts hydroxyls (-OH) to aldehydes that then react with hydrizide groups. Sodium m-Periodate reacts most efficiently with cis-diols (as found in Sialic Acid) at a concentration of 1mM, but increasing concentrations (>10mM) should ensure oxidation of many sugar residues.

Carbohydrate moites on glycoproteins can be conveniently oxidized to aldehydes in a 10mM periodate solution for 30 minutes and then desatled. The resulting aldehydes can be conjugated to hydrizide groups of PDPH crosslinker or Biotin-Hydrizide for protein crosslinking or biotinylation of your glycoprotein, respectively.