Proteomics comparison of exosomes from serum and plasma between ultracentrifugation and polymer-based precipitation kit methods.

Exosomes are vesicles with sizes ranging from 30 to 150 nm. The analysis and detection of blood exosomes offers an effective route for cancer diagnosis, prognosis assessment, and therapeutic evaluation of diseases. Due to the difference in separation procedure, collection method and the usage of anticoagulants, serum and plasma samples show diversity test results. In order to evaluate the isolation effect of exosomes in serum and plasma samples, two commonly used exosomal isolation methods, ultracentrifugation and polymer-based precipitation kit, were used, respectively. And the isolation effects were evaluated by comparing the composition and abundant of proteins from isolated exosomes based on MS-based proteomics analysis. The results showed that the plasma exosomes extracted by ultracentrifugation identified more exosome biomarkers, and the concentrations of these biomarkers were higher than others. And plasma exosomes could be a better sample for blood-based proteomics research of exosomes. It would be more useful for future targeted biomarker discovery.