Table 1.
Methods to isolate extracellular vesicles (EVs).
| Method | Methodology | Advantages/Disadvantages | Ref. |
|---|---|---|---|
| Differential centrifugation | * Stepwise manner. * Sequential centrifugations, increasing the centrifugation speed. |
- Low cost, large quantities of the solution, absence of chemicals. - Complexity, equipment (ultracentrifuge), and efficiency depend on the type of rotor. |
[39,86,87] |
| Density gradient centrifugation | * Initial samples are EVs, partially isolated by differential centrifugation. * Use of solutions of sucrose, iohexol, or iodixanol. |
- Pure preparations, no contamination with viral particles, absence of chemicals. - Complexity, equipment (ultracentrifuge), loss of sample. |
[39,88,89] |
| Chromatography | * Filtration through columns of porous smaller than EV of interest | - Rapid isolation, preservation of vesicle integrity. - Limitations of sample volume, specialized equipment, complexity. |
[90,91] |
| Ultrafiltration | * Use of porous membranes to trap molecules with a specific size through successive steps to obtain EVs with the desired size. * Based on size and mass. |
- Simplicity, processing of many samples, lack of limitations on sample volume. - Sample contamination by proteins, loss of sample by filter plugging |
[92,93] |
| Precipitation by chemicals | * Use of organic solvents, polyethylene glycol, sodium acetate, or protamine. | - Relatively quick, able to be used in a wide range of samples. - Contamination with non-EV proteins, retention of chemicals, long processing time. |
[94,95,96,97] |
| Precipitation by polymers | * Commercial kits * Use of super hydrophilic polymers solutions, or PEGs. * Diminished the solubility of EVs and generation of a pellet precipitate. |
- Simple procedure, no need for additional equipment. - Usually costly, not be good for large samples of EVs, high concentration of impurities. |
[39,90] |
| Precipitation by protein surfaces (immunoassay) | * Immunoprecipitation. * Magnetic beads coated with antibodies for common EV surface proteins, such as CD63, CD9, and CD8. * Use after a centrifugation method for isolation. |
- High purity and selectivity. - High cost, selectivity may be too high, difficulties for detachment antibodies and to analyze the intact vesicles. |
[98,99] |