Figure 2.
Comparison of extracellular vesicle protein identifications after SEC and ultracentrifugation
(A and B) Size distribution (A) and particle count (B) characterization of extracellular vesicles (EVs) isolated from platelet-poor plasma (PPP) by using size-exclusion chromatography (SEC) or ultracentrifugation (UTC) by nanoparticle tracking. SEC resulted in a significantly higher particle count than when using UTC (p = 0.0008).
(C) Transmission electron microscopy image of EVs isolated from plasma by using SEC.
(D) Experiments from five replicate analyses of pooled PPP showed that SEC produced approximately 3-fold more identifiable proteins compared with UTC. Dark-blue bars represent the total number of protein identifications for each replicate, and light-blue bars represent the number of the identified proteins that associate with the ExoCarta database.
(E) Histogram displaying the coefficient of variation (CV) calculated from protein intensity measurements of each identified protein over the five replicates. In total, 562 proteins with a CV of less than 25% were identified with SEC, compared with just 73 with UTC.
(F) CVs for several EV marker proteins identified by SEC and UTC.
(G) Protein identifications from each method plotted as ranked abundance against log10 intensity shows that SEC results in higher recovery of EV proteins than UTC.