Table 1.
Isolation techniques used to obtain EVs.
| Isolation Method | Principal Mechanism | Equipment | Advantages | Disadvantages | Ref. |
|---|---|---|---|---|---|
| Differential centrifugation | Centrifugal force with ultrahigh-speed rotation | Centrifuge, ultracentrifuge, high-speed rotors, and rotary tubes | Straight forward, no additional chemical substance or reaction, high capacity, low processing cost, and high reproducibility | Expensive machinery and specialized equipment. Medium to high processing time (120–600 min) | [43,44] |
| Density gradient ultracentrifugation | Buoyant density in chemical solutions | Centrifuge, ultracentrifuge, high-speed rotors, and rotary tubes | Accurate particle separation, high capacity, minimum contamination chance | Expensive machinery and specialized equipment. High processing time (250 min–2 d) | [39,40,41] |
| Size exclusion chromatography | Separation of biomolecules based on their hydrodynamic radios | Porous beads | Prevention of EV aggregation and preserving their integrity. Low to medium processing time (1 mL/min) | Prospective contaminants of the target size and size overlap confusion. Low capacity | [45] |
| Commercial kit precipitation | Decreasing the solubility of EVs by polymer coating | Superhydrophobic polymers (e.g., PEG) and centrifugation | Simplicity, no need for further chemicals, and fast process (30–60 min) | Unspecified isolation, high polymer contamination, expensive, and low capacity | [46] |
| Immunoprecipitation | Antibody–tetraspanin bounding | Antibody-coated microbeads | Highly specified isolation, medium processing speed (240 min), high purity | Altered surface properties of EVs, difficult separation from beads, loss of EVs, expensive, and low capacity | [47] |
| Ultrafiltration | Filtration of assorted sizes | Porous membranes, and centrifugation | Highly specified sizes, simplicity, and fast processing (130 min) | Membrane plugging, unwanted contaminants, risk of low yield | [48] |
| Microfluidic | Entrapment of EVs by immunoaffinity or within porous structures | Microfluidic device | Highly specified isolation, simplicity, and fast processing for small sample size | Expensive machinery, small capacity, low yield | [49] |