FIG. 1.

Schematics of filtration systems for isolation of EVs. (a) Schematic showing the design of the cyclic tangential filtration system, with SEM images of 200 nm and 30 nm pore sized membranes. (b)–(d) Schematic illustration of three difference methods for isolating different sizes of fluorescent beads using particles larger than the 200 nm (red), particles smaller than 200 nm but larger than 30 nm (green), and particles smaller than 30 nm (yellow): (b) direct filtration (DF), (c) single-cyclic filtration (scTFF), and (d) dual-cyclic TFF (dcTFF).