Figure 4. Cryo-immunogold EM micrographs of PROSPR isolated EVs.
Presence of tetraspanin CD9 (10 nm colloidal gold particles) was observed as attached to the internal/external face of the membrane in single layered exosome-like vesicles (a,b) and in multilayered exosome-like vesicles (c). Presence of the ESCRT protein Alix was also confirmed (10 nm colloidal gold particles) in exosome-like vesicles isolated by PROSPR from blood plasma (d–f). Scale bars in all images represent 40 nm.