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Updated: May 9, 2026

High-throughput and Comprehensive Drug Surveillance Using Multisegment Injection-Capillary Electrophoresis-Mass Spectrometry
Published on: April 23, 2019
Drug-to-antibody ratio (DAR) and drug load distribution by LC-ESI-MS
1Protein Analytical Chemistry, Genentech Inc., South San Francisco, CA, USA.
Abstract:
This chapter describes an LC-ESI-MS method for the DAR and drug load distribution analysis that is suitable for lysine-linked ADCs. The ADC sample is desalted using a reversed-phase LC column with an acetonitrile gradient prior to online MS analysis. The MS spectrum is processed (deconvoluted) and converted to a series of zero charge state masses that corresponds to the increasing number of drugs in the ADC. Integration of the mass peak area allows the calculation of the DAR and drug load distribution of ADCs.
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