Ultrafiltration and size exclusion chromatography combined with asymmetrical-flow field-flow fractionation for the isolation and characterisation of extracellular vesicles from urine

Extracellular vesicles (EVs) have a great potential in clinical applications, however their isolation from different body fluids and their characterisation are not yet optimal or standardised. Here we report the results of examining the performance of ultrafiltration combined with size exclusion chromatography (UF-SEC) to isolate EVs from urine. The results reveal that UF-SEC is a fast method and provides high purity. Furthermore, we introduce asymmetrical-flow field-flow fractionation coupled with a UV detector and multi-angle light-scattering detector (AF4/UV-MALS) as a characterisation method and compare it with the applicabilities and limitations of current methods. We demonstrate that AF4/UV-MALS is a straightforward characterisation method for urinary EVs.