Exosomal biomarkers: A novel frontier in the diagnosis of gastrointestinal cancers

Table 3 Comparison of exosome isolation methods: Advantages and disadvantages

Isolation method	Advantages	Disadvantages	Ref.
Ultracentrifugation	Considered the gold standard; convenient and cost - effective; can be combined with density - gradient mechanisms to achieve high - purity exosome yield and aid in morphological identification	Co-purifies lipoproteins and protein aggregates alongside EVs; combined with density - gradient mechanisms may result in lower yield and longer processing time	[53-59]
Ultrafiltration	Simple, faster procedure, no need for specialized equipment; refined method can achieve higher capture efficiency of different - sized exosomes compared to ultracentrifugation	Low recovery rate due to protein contamination and potential exosome damage during filtration; filter clogging can occur	[55,57,60-62]
Polymer - based precipitation separation (using PEG)	Simple and scalable	Pellets may be contaminated with other particles, large aggregates, and associated proteins, potentially affecting subsequent analysis	[58,63]
Microfluidic technology	Promising for rapid, efficient exosome isolation; can achieve high recovery rate in a short time	Not suitable for large - volume sample separation due to handling limitations	[49,64]
Other techniques (chromatography, hydrostatic filtration dialysis, size - exclusion chromatography, lipid - based separation, immunoaffinity - based methods)	Allow for seamless integration with clinical diagnostics, broadening potential clinical applications of exosomes	N/A	[49]

EVs: Extracellular vesicles; PEG: Polyethylene glycol; N/A: Not applicable.