Adipic acid dihydrazide

Homobifunctional cross-linking reagent that is specific for aldehydes resulting in relatively stable hydrazone linkages. This is commonly used in the linking of glycoproteins, such as antibodies, in a site specific fashion following periodate oxidation. Oxidation and coupling may conveniently be performed at pH 5.0 due to the low pKa of the hydrazide which avoids competition by primary amines. Note that the hydrazone bond may be stabilized by selective reduction using, for example, sodium cyanoborohydride.