Zetaview nanoparticle tracking analysis nta

The exosome size distribution and concentration were determined using ZetaView nanoparticle tracking analysis (NTA) (Particle Metrix, Germany) according to the manufacturer’s instructions. Exosome samples were diluted in 0.1 μm filtered 1× PBS (catalog number 10010072; Gibco) to fall within the instrument’s optimal operating range (see Table S1 in the supplemental material).

EV yields were quantified via Brownian diffusion size analyses using ZetaView Nanoparticle-tracking analysis (NTA) instrumentation (Particle Metrix, Meerbusch, Germany). Sample aliquots were diluted 10²–10⁶-fold to achieve optimal concentration for analysis; 1.0 mL of diluted sample was used for each analysis. Light scattering of individual particles in solution was digitally recorded, particle trajectory and displacement were automatically analyzed by image analysis tracking software and the particle-size distribution was determined from the observed Brownian motion of individual particles according to the Stokes-Einstein relationship.

Quantification of purified OMVs was performed using ZetaView™ Nanoparticle Tracking Analysis (NTA; Particle Metrix, Germany) as previously described (6 (link)). Briefly, OMVs were diluted in DPBS to a concentration of 50 - 200 particles per field of view. NTA measurements of OMV samples were performed using a 488 nm 40 mW laser and CMOS camera by observing 11 cell positions at 25°C with 60 frames captured per position. Analysis was then performed using ZetaView software version 8.05.14 SP7 (minimum brightness: 30, maximum brightness: 255, minimum area: 5, maximum area: 1000, minimum trace length: 15). The average of three biological replicates was calculated and plotted as particle size versus particles per ml using GraphPad Prism v9.3.1.