Identification of nanoparticles by nanoparticle tracking analysis

Nanoparticle tracking analysis (NTA) measurements were performed by using a NanoSight NS500 instrument (NanoSight NTA 2.3 Nanoparticle Tracking and Analysis Release Version Build 0025). The size distribution and quantification of exosome preparations were analyzed by measuring the rate of Brownian motion with a NanoSight LM10 system (NanoSight, Wiltshire, United Kingdom) equipped with fast video capture and particle-tracking software. Purified exosomes from NE, EE, and EI samples were diluted in 500 μl of a solution of 1× PBS/5 mM EDTA and disaggregated by using a syringe and needle (29-gauge). After this procedure, the sample was injected into a NanoSight sample cubicle. The mean ± SD size distribution of ESC exosomes was determined, and the mean number of particles per milliliter was compared between endometriosis patients (exosomes derived from EE and EI ESCs) and exosomes derived from eutopic NE cells of healthy subjects (Riches et al. 2014).