Biotinylating Antibodies Using Biotin-Long Chain (LC) Hydrazide

Hydrazide derivatives are useful for biotinylating antibodies at oxidized carbohydrate groups. This protocol uses oxidation conditions that will convert most if not all possible hydroxyl sites to aldehydes. Each antibody may require different oxidation conditions to optimize labeling. Some monoclonal antibodies may be deficient in glycosylation, making this method suboptimal. Other labeling reagents (fluorophores) are also available as hydrazides. Hetero-bifunctional cross-linkers (e.g., β-maleimidopropionic acid hydrazide [BMPH]) are also available to cross-link other targets to carbonyls.