Table 1.

Current conventional exosome isolation methods.

Isolation technique	Principle	Time	Advantages	Disadvantages
Differential ultracentrifugation	Particles with various size and density demonstrate various sediment speed under centrifugation	5–18 hours	✓ Suitable for large volume preparation	➣Require expensive equipment ➣Potential damage because of the high-speed centrifugation ➣Time-consuming
Size	Separate with specific molecular size exclusion	2–4 hours	✓ Isolate native exosomes	➣ Exosomes and proteins clogging on nanopores ➣ Potential isolate other nanovesicles in similar size with exosomes
Bead	On the basis of interaction between antibodies/ligan ds and exosome markers	2–6 hours	✓ High-purity ✓ Useful for isolating specific exosomes from target origin	➣Expensive antibodies functionalization ➣Low yields and processing volume ➣Exosome markers must be optimized
Polymer	High hydrophilic water-excluding polymers changes the solubility of exosomes	0.5–12 hours	✓ Available for all types of samples ✓ Easy to use	➣Potential polymeric, protein aggregates, and other extracellular vesicles contaminants.