UFLC-Derived CSF Extracellular Vesicle Origin and Proteome.Cerebrospinal fluid (CSF) extracellular vesicles (EVs) show promise as a source of neurological disease biomarkers, although their precise origin is poorly understood.  This study describes the application of ultrafiltration LC (UFLC) to CSF-EVs, compared with ultracentrifugation (UC), and explores CSF-EV origin.  EVs are extracted from human CSF by UC and UFLC and characterized using nanoparticle tracking analysis, electron microscopy, and immunoblotting.  UFLC-isolated particles have size, morphology, and marker expression characteristic of EVs.  UFLC provides greater EV yield (UFLC 7.90 × 108  ± SD 1.31 × 108 EVs mL-1 CSF, UC 1.06 × 108  ± 0.57 × 108 p < 0.001).  UFLC enhances purity, proteomic depth (UFLC 622 ± 49, UC 298 ± 50, p = 0.001), and consistency of quantification (CV 17% vs 23%).  UFLC improves yield and purity of CSF-EVs. 
UFLC
This study describes the application of ultrafiltration LC (UFLC) to CSF-EVs, compared with ultracentrifugation (UC), and explores CSF-EV origin. 
ultrafiltration LC
This study describes the application of ultrafiltration LC (UFLC) to CSF-EVs, compared with ultracentrifugation (UC), and explores CSF-EV origin. 
ultracentrifugation (UC)
EVs are extracted from human CSF by UC and UFLC and characterized using nanoparticle tracking analysis, electron microscopy, and immunoblotting. 
nanoparticle tracking analysis
EVs are extracted from human CSF by UC and UFLC and characterized using nanoparticle tracking analysis, electron microscopy, and immunoblotting. 
electron microscopy
EVs are extracted from human CSF by UC and UFLC and characterized using nanoparticle tracking analysis, electron microscopy, and immunoblotting. 
immunoblotting
EV and CSF proteomes are analyzed by LC-MS/MS. 
LC-MS/MS