Labeling Antibodies with N-Hydroxysuccinimide-Long Chain (NHS-LC)-Biotin

Labeling antibodies with biotin (biotinylation) is a useful and simple technique. Biotin's small size (244 Da) usually has little effect on the biological activity of the protein target. The most common way to biotinylate an antibody is to cross-link a biotin succinimidyl ester to a primary amine. There are many commercially available types of biotin analogs that can be used for labeling. They vary in reactive group chemistry as well as spacer length. For example, a common analog used for biotinylation is the succinimidyl ester of biotin with an aminohexanoic acid spacer (Long Chain or LC-Biotin), utilized here. A PEG spacer of varying length can also be used.