Table 1. The traditional isolation method of exosome.

Method	Advantage	Disadvantage	Feature	References
Ultracentrifugation	Widely used, Avoiding cross contamination	High time consumption, High cost, Structural damage,	Suitable for separations with significant differences in sedimentation coefficients	Zhang et al. (2020), Livshits et al. (2016)
Density gradient centrifugation	High purity	High cost	Using in combination with ultracentrifugation to improve the purity	Zhang et al. (2020), Livshits et al. (2016)
Polymer precipitation	Low cost	Low purity	Using reagents to reduce solubility in the centrifuged state	Zhang et al. (2020), Rider, Hurwitz & Meckes (2016)
Size-exclusion chromatography	Complete tructure, simple operation, fast speed	Low purity	Using different molecular sizes to screen small molecules into the gel pores for elution separation	Zhang et al. (2020), Böing et al. (2014)
Ultrafiltration	Low cost, High enrichment efficiency, Complete activity	Low purity	Screening with ultrafiltration membranes	Zhang et al. (2020), EV-TRACK Consortium et al. (2017)
Immunoaffinity chromatography	Strong specificity, High sensitivity, High purity, High yield, Low sample requirements	Harsh storage condition	Antigen-antibody specific binding to achieve separation	Zhang et al. (2020), Li et al. (2017)