Exosomes: Emerging Therapy Delivery Tools and Biomarkers for Kidney Diseases

Figure 1

Five main traditional methods of exosome separation. Traditional methods are based on the physical, chemical, and biological properties of exosomes. Sequential ultracentrifugation is used to separate the exosomes, according to the different sedimentation coefficients of exosomes, cells, and debris. Ultrafiltration and size-exclusion chromatography depend on size: only exosomes can pass through a certain molecular-weight cut-off membrane and exhibit longer retention times in the stationary phase. When PEG is added, the surroundings are hydrophobic and promote deposition at the bottom. The beads are combined with specific antibodies to interact with the surface proteins of exosomes and can easily be sorted.