Benchmarking five extracellular vesicle proteomics workflows, including low-input Exo-insert and Exo-SP3, for deep mass spectrometry profiling

Small extracellular vesicles (sEVs) are key mediators of intercellular communication, influencing diverse pathological processes, including cancer. While mass spectrometry (MS) has enabled the proteomic analysis of sEVs, sample preparation losses remain a critical bottleneck, particularly for scarce tissue-derived sEVs (Ti-EVs). Here, we systematically benchmark five proteomic workflows introducing Exo-insert, a novel single-vessel method, and Exo-SP3, across both Ti-Evs and cell culture-derived sEVs (CCM-EVs) at low input (0.5-4 {micro}g). Exo-insert and Exo-SP3 enable the identification of [~]1100 protein groups from as little as 0.5 {micro}g sEV input. Notably, optimal sample preparation for MS is source-dependent: Exo-insert and Exo-SP3 display divergent performance across sEV sources. Comparative DDA/DIA analyses establish sample preparation as the primary determinant of proteome recovery, offering a practical framework that matches workflows to sEV amounts and source-specific content for biomarker discovery.