Merck, A0638-25G, Adipic acid dihydrazide

Adipic acid dihydrazide is a homobifunctional cross-linking reagent that is specific for aldehydes. This results in relatively stable hydrazone linkages. Adipic acid dihydrazide is generally used in the linking of glycoproteins, like antibodies, in a site-specific fashion following periodate oxidation. Oxidation and coupling may be performed at pH 5.0 due to the low pKa of the hydrazide which avoids competition by primary amines.