Table 1.

Overview of the most popular exosome isolation techniques.

Exosome isolation techniques	Methods	Advantages	Limitations	Ref.
Ultracentrifugation techniques	Differential ultracentrifugation	Easy to use	Time consuming	(69)
		Little sample pretreatment	Requires large starting sample volumes
		Affordability over time	Low exosome recovery
	Density gradient centrifugation	Effective for exosomes from protein aggregates and non-membranous particles	Low exosome recovery	(70)
		Useful for separating exosomes and other EVs from body fluids
Size-based isolation techniques	Ultrafiltration	Less time consuming	Particle deformation	(67)
		Requires no special instrumentation	Lysis of exosomes
	Sequential filtration	Automatable	Rigid components associated with cellular debris are filtered away	(72)
		Produces intact and biologically active exosome material
	Size exclusion chromatography	Preserves vesicle structure, integrity, and biological activity	Requires run times of several hours	(68, 71)
			Not easily scalable
			Cannot be used for high throughput applications.
Immunoaffinity capture-based techniques	Magneto-immunoprecipitation	Higher isolation efficiency	Protein/antigen used to capture the exosomes must be expressed on the surface of exosomes	(66, 67)
		Can handle large sample volumes
		Preserves the activity of exosomal proteins	Specificity of the assay is limited to specificity of the antibody.
Exosome precipitation	Polyethylene glycol precipitation	Quick	Lack of selectivity	(69)
		Simple
		Requires little technical expertise or expensive equipment
		Can be used for various starting volumes