Characteristics of exosomes isolated from plasma immediately after phlebotomy (○) and after 30 days stored at −80°C (●). (A) Number of exosome particles. (B) Exosomes characterization. b1: electron microscope (scale bar 100 nm) and b2: Western blot for CD63 (exosomal marker); lane 1: Fresh and lane 2: stored. (C) Expression of miRNA RNU6B in exosomes. (D) Venn diagram of proteins identified in fresh and stored exosomes.