Drug-to-Antibody Ratio/Protein Conjugation
Drug antibody ratio (DAR) is an important parameter of antibody drug conjugates (ADC) and refers to the average drug to antibody ratio for a given preparation of ADC. The significance of DAR in biotherapeutics is a primarily as a measure of drug loading for an ADC. Using a combination of intact mass measurement of the ADC as well as peptide mapping, an accurate DAR can be determined with site localization.
Figure 1. Workflow for drug-to-antibody/protein conjugation ratio calculation.
Figure 2. Comparison of Sigma-mAb to Sigma-ADC following conjugation.