As one major component of an antibody-drug conjugate (ADC), the antibody is the key for target specificity and serves as the cargo to deliver the cytotoxic drug (payload). A payload drug can be attached to different sites on an antibody using diverse conjugation chemistry. Multiple endogenous amino acids can serve as potential conjugation sites. However, to achieve more precisely controlled site-directed conjugations and subsequently a narrower distribution of drug-to-antibody ratio (DAR), special moieties with unique conjugation chemistries are engineered into antibody sequences in our antibody design services. Learn more: bioconjugation services