Capillary zone electrophoresis (CZE)-mass spectrometry (MS) has attracted tremendous attention in top-down proteomics (TDP). However, its reproducibility and long-term repeatability for TDP remain con Show more
Capillary zone electrophoresis (CZE)-mass spectrometry (MS) has attracted tremendous attention in top-down proteomics (TDP). However, its reproducibility and long-term repeatability for TDP remain concerns, most likely due to capillary coating. Here, we present an improved procedure for making linear polyacrylamide (LPA) coating, the most widely used coating in CE-MS-based proteomics, to boost the reproducibility and long-term repeatability of CZE-MS-based TDP. We focused on the step of degassing the polymerization solution, a critical step for achieving consistent LPA coating quality. The CZE-MS system using LPA-coated capillaries prepared with the optimal degassing procedure produced excellent reproducibility and repeatability for proteoform analysis. The 210 CZE-MS runs of three protein samples (a standard protein mixture, an Show less