Optimising size exclusion chromatography for extracellular vesicle enrichment and proteomic analysis from clinically relevant samples

We performed a quantitative evaluation and optimization of SEC for separating EVs from contaminating proteins. This optimized method was applied to enrich EVs from healthy plasma and MDA-MB-231 cancer cell culture medium. By spiking-in cancer cell-derived EVs to healthy plasma and then performing SEC enrichment, we were subsequently to detect cancer cell line- specific proteins by LC-MS/MS. We quantified the limit of detection and showed that cancer EV-associated proteins were detectable by nano-LC-MS/MS when as little as 1% of the total plasma EV number were derived from a cancer cell line.