The concentrations and particle size distributions of EVs present in conditioned culture medium were analyzed using NanoSight N300 (Malvern Panalytical, UK), based on their properties of both light scattering and Brownian motion. For each sample, three videos of 60-s duration were recorded, with a short delay between recordings. The recorded video was analyzed with NTA software, which tracked many particles individually and, using the Stokes-Einstein equation, calculated their hydrodynamic diameters. Camera sensitivity and detection threshold were set to 12 and 5, respectively. The concentration of each detection sample was between 2 × 108 and 6 × 108 particles/ml, which was prepared by 10-fold dilution of the stock conditioned culture medium with PBS that has passed through a 0.22-μm filter. Samples were administered and recorded under controlled flow, using the NanoSight syringe pump and script control system.