fig2

Figure 2. Analysis of the plasma sEV count at single-sEV level using PBA. (A) TEM of plasma sEVs. Solid black lines represent 100 nm scale bars; (B) Size distribution of plasma sEVs by NTA; (C) Western blot analysis of plasma sEVs using antibodies CD9, TSG101, GM130, and Calnexin. Plasma samples from Cohorts 1 and 2 were subjected to PBA analysis using Panel260 and Panel550, respectively; Comparison of plasma sEV count detected by PBA between HC and patients with TC in Cohort 1 (D) and 2 (E), the data of plasma sEV count in Cohort 1 was analyzed using the Student’s t-test while the data in Cohort 2 was analyzed using the Mann‒Whitney U test; The differences in the number of sEV surface proteins detected by PBA between HC and TC in Cohort 1 (F) and 2 (G), the data of protein count in Cohort 1 was analyzed using the Student’s t-test while the data in Cohort 2 was analyzed using the Mann‒Whitney U test; The protein concentration of isolated sEVs was detected using the BCA kit, and was compared between HC and TC in Cohort 1 (H) and 2 (I), the data of protein concentration in Cohort 1 and 2 was analyzed using the Student’s t-test; ROC curves were plotted using the detected plasma sEV counts of HC and TC in Cohort 1 (J) and 2 (K). sEV: Small extracellular vesicle; PBA: proximity-dependent barcoding assay; TEM: transmission electron microscopy; NTA: nanoparticle tracking analysis; CD9: cluster of differentiation 9; TSG101: tumor susceptibility gene 101; GM130: Golgi Matrix 130; HC: healthy controls; TC: thyroid carcinoma; BCA: Bicinchoninic acid assay; ROC: receiver operating characteristic; AUC: area under the curve; CI: confidence interval.