FIG 2.

Physicochemical characterization of particles produced by B. longum NCC2705. The crude extracellular vesicle (EV) fraction was isolated from the B. longum suspension. (a) EV fraction was negatively stained with uranyl acetate, and images were obtained using a TEM. (b) EV size distribution was assessed using a NanoSight nanoparticle characterization system. (c) Crude EV fraction and whole-cell lysate were analyzed using Western blotting with an anti-PstC antibody to detect membrane protein. Protein (d) and DNA (e) concentrations were determined using a bicinchoninic acid protein assay and QuantiFluor dsDNA system, respectively. Each data point represents one EV fraction (n = 8). The error bars indicate the means ± standard deviations (SDs).