Table 1.

Summary of a comparative study of existing conventional exosome isolation techniques.

Isolation Technique	Isolation Principle	Appraisal Parameters			Advantages	Disadvantages	References
		Time	Yield	Purity
Ultracentrifugation	Density-based	*	*	**	The gold standard	Time-consuming; low yield; moderate purity;	[38,46]
Immunoaffinity-capture	Affinity-based	**	**	***	Highly specific and pure	Expensive; strict pH condition; constrained use	[40,41]
Size-exclusion chromatography	Vesicles Size	**	**	**	Simple, rapid, moderate yield	Poor specificity; scaling problems	[44,47,48]
Polymer-based precipitation	Surface charge-based	*	***	*	Simple and user-friendly, high yield	Expensive; low specificity; poor purity; scaling problems	[22,49]
Ultrafiltration	Molecular weight and size-based	**	*	**	Simple, no specific instrument	Clogging; low yield, low specificity, time-consuming	[50,51,52]

Appraisal parameters are categorized by ***, **, and * imply very good, moderate, and poor performances, respectively.