The size and concentration of the isolated EVs were evaluated by NTA using the NanoSight® LM10 (Malvern Instruments, UK) analyzer, equipped with a blue laser (45 mW at 488 nm) and a C11440-5B camera (Hamamatsu Photonics K.K., Japan), at several dilutions according to the manufacturer’s instructions. Each sample was measured in triplicate, with a camera setting of 15, an acquisition time of 60 s, and a detection threshold setting of 5. At least 200 completed tracks were analyzed per video. NTA analytical software version 2.3 was used for data analysis and capture.
The immunocytochemical identification of exosomes from plasma and total blood with monoclonal antibodies to tetraspanin CD9 was performed as described previously [45 (link)]. Quantitative analysis of the exosomal tetraspanines on the surface of the isolated EVs was carried out using flow cytometry, as described previously [46 (link)]. Flow cytometry was performed on the Cytoflex (Becman Coulter, USA), using the CytExpert 2.0 Software. The MFI of the stained exosomes was analyzed and compared to the isotype control (BD bioscience, USA).