Monoclonal antibodies are becoming a core aspect of the pharmaceutical industry. Together with a huge
therapeutic potential, these molecules come with a structural complexity that drives state-of-the-art
chromatography and mass spectrometry (MS) to its limits. This article discusses the use of micro-pillar array
columns in combination with mass spectrometry for peptide mapping of monoclonal antibodies (mAbs) and
antibody–drug conjugates (ADCs). Micro-pillar array columns are produced by a lithographic etching process
creating a perfectly ordered separation bed on a silicon chip. As a result of the order existing in these columns,
peak dispersion is minimized and highly efficient peptide maps are generated, providing enormous structural
detail. Using examples from the author’s laboratory, the performance of these columns is illustrated.