Utilization of Selenocysteine for Site-Specific Antibody Conjugation

: Site-specific conjugation methods are becoming increasingly important in building next-generation antibody-drug conjugates. We have developed a site-specific conjugation technology based on monoclonal antibodies with engineered selenocysteine (Sec) residues, named selenomabs. Here, we provide protocols for the engineering, expression, and purification of selenomabs in single-chain variable fragment (scFv)-Fc format. Methods for selective conjugation of selenomabs to selenol-reactive compounds and analytical characterization of selenomab conjugates are also included.