Waters Corporation enhances its mass spectrometry portfolio by acquiring MOBILion Systems, integrating advanced ion-mobility separation technology for proteomics.

Abstract. Mass-spectrometry-based single-cell proteomics has evolved from an unconventional idea into a rapidly advancing technology that is opening new pe

Waters Acquires Mobilion to Bolster Discovery Proteomics, Posts Rise in Q3 Revenue

AbstractQuantitative proteomics requires robust, accurate labeling strategies that minimize sample handling and preserve analytical sensitivity. Enzymatic 18O labeling offers a simple, universally applicable alternative to other isotopic labeling methods, but has been limited by incomplete labeling, back-exchange, and reliance on post-digestion, in-solution 18O labeling workflows that are impractical and introduce cumulative sample losses. Here, we present a fully integrated platform combining single-pot solid-phase-enhanced sample preparation (SP3) with direct on-bead trypsin-catalyzed C-terminal 18O labeling (SP-18O) during proteolytic digestion and data-independent acquisition mass spectrometry (DIA-MS). By performing 18O incorporation directly on-bead during digestion, the SP-18O approach eliminates the need for a separate post-digestion labeling step and associated sample losses compared to conventional enzymatic labeling workflows. Integration with DIA-MS further improves identification confidence and quantitative performance through distinctive y-ions. The platform is validated on two biologically distinct sample types, extracellular vesicles (EVs) secreted from model cancer cells and immunoaffinity-enriched protein complexes from Drosophila head tissue, demonstrating robustness and generalizability. This integrated strategy offers a practical, cost-effective solution for accurate quantitative proteomics while minimizing sample loss and analysis time.

ABSTRACT Top-down proteomics approaches have emerged as powerful strategies for investigating the effects of proteoform modifications, such as amino acid substitutions, truncation, and post-translational modifications (PTMs), on protein function and activity in biological systems. In addition to proteoform structure, proteoform abundance also influences cellular biochemistry by regulating signaling pathways and altering protein–protein interaction dynamics. Thus, accurate measurement of proteoform abundance is critical for examining cellular phenotypes and disease states. The application of quantitative proteomics strategies to top-down proteomics, however, has been challenging due to difficulties in extracting and solubilizing intact proteins, the wide dynamic range in proteoform abundance, limited sensitivity for low‑abundance species, and the need for advanced separations and robust deconvolution algorithms. Recent advances in top-down proteomics strategies, including methods to improve proteoform mass spectrometry data collection, sample preparation, and data analysis, have laid the groundwork for quantitative top-down proteomics. Here, we provide a comprehensive review of current quantitative top-down proteomics strategies and examine the applications, advantages, and challenges, including label-free, metabolic labeling, chemical tag labeling, and targeted quantification strategies.

Linking spatial context to molecular depth in tissue remains difficult. Here, the authors combine high-plex imaging, open-source image analysis and ultra-sensitive mass spectrometry to profile single ...