The most common types of bioconjugation include coupling of a small molecule (such as biotin or a fluorescent dye) to a protein. Antibody-drug conjugates such as Brentuximab vedotin and Gemtuzumab ozogamicin are examples falling into this category.
Protein-protein conjugations, such as the coupling of an antibody to an enzyme, or the linkage of protein complexes, is also facilitated via bioconjugations.
Other less common molecules used in bioconjugation are oligosaccharides, nucleic acids, synthetic polymers such as polyethylene glycol, and carbon nanotubes.