Fig. 2.

Isolation of plasma-derived exosomes by size-exclusion chromatography. An aliquot (1 mL) of undiluted plasma from Donor 1 was passed through a sepharose (CL-2B) column, and 30 fractions of 0.5 mL each were collected. (a) SDS–PAGE stained with silver and protein concentration values of fractions 6–14 were measured by Bradford assay (fractions 6, 7 and 8 were below the lower limit of detection) and fractions 6–9 were analysed by flow cytometry, after coupling of vesicles to 4 µm latex beads, for the presence of antigens CD9 (1:10) and CD81 (1:10). The secondary anti-mouse antibody was conjugated to FITC and was used at a 1:100 dilution. MFI: mean fluorescence intensity. (b) Fractions 7–11 were submitted to NTA on a NanoSight LM10 (software version 3.0).