Localization of αsyn oligomers within exosomes: (A) Luciferase assay with exosomes derived from human H4 cells transfected with S1/S2 or 0.1% saponin/or 0.1% saponin. (B) Luciferase assay with exosome-free supernatants after αsyn oligomer digestion using 0.25% trysin and/or 0.1% saponin. (C) Dot blot approach with exosomal fraction (exo) and exosome free supernatant (sup) from H4 cells transfected with S1/S2 after αsyn oligomer digestion using 0.25% trysin and/or 0.1% saponin. Probing with syn-1 antibody shows only a complete digestion of αsyn oligomers when trypsin and saponin are used concurrently. Signal of exosomal marker CD63 is abolished by addition of solely trypsin.