For precipitation techniques to isolate extracellular vesicles, samples containing EVs are incubated with a buffer that changes their solubility or sedimentation rate. One common precipitation buffer uses polyethyleneglycol (PEG), a hydrophilic polymer. By incubating EVs with PEG, it decreases the solubility of EVs in solution and, using a very gentle centrifugation step, causes accumulation of EVs at the bottom of the tube.
