Table 1.

Main advantages and disadvantages of different exosomal isolation techniques.

Isolation Method	Main Advantages	Main Disadvantages	Ref.
Sucrose density gradient ultracentrifugation	Easy to perform, requires little technical expertise.	Time-consuming, risk of exosomal rupture and loss, requires a large volume of samples.	[47,48,49]
Size-based methods (i)Ultrafiltration	Fast method with no requirement for special equipment.	Risk of exosomal rupture and loss.	[50,51,52]
(ii)Size-exclusion chromatography	Preserves exosomal structure with high purity and good reproducibility.	Laborious, possible contamination with lipoproteins.	[50,53]
Precipitation	Easy to perform, minimal cost with no requirement for special equipment.	Risk of contamination with lipoproteins.	[54,55]
Immunoaffinity-based methods	Preserves exosomal structure with high purity, requires a small volume of samples with a low experiment time.	Low yield, exosomal tags need to be established.	[52,56]
Microfluidics-based methods	Preserves exosomal structure and compositions, requires a small volume of samples and reagent consumption at a low cost.	Lack of method validation, standardization and large-scale tests on clinical samples.	[49,52,57]