Table 2.
Summary of EV Isolation Techniques
| Isolation Method | Principle | Yield | Purity | Advantages | Disadvantages | Reference |
|---|---|---|---|---|---|---|
| Differential Ultracentrifugation | Sequential high-speed spins pellet EVs by size/density | Low–Moderate (some EV loss) | Moderate | Widely used, scalable | Time-consuming, co-isolation of similarly sized contaminants | [43] |
| Density Gradient Centrifugation | Ultracentrifugation with a density medium (eg, sucrose) separates EVs by buoyant density | Low (multi-step process) | High | High purity, resolves subtypes | Labor-intensive | [43,44] |
| Polymer Precipitation | Hydrophilic polymers (eg, PEG) reduce EV solubility, causing EV aggregation and low-speed co-precipitation | High (efficient particle recovery) | Low | Simple; high yield | Non-specific protein contamination | [45] |
| Ultrafiltration | Size-based filtration using membranes (pore size < EV diameter) to retain EVs while smaller molecules pass through | Low (EVs adsorb to filter) | Low | Fast | Filter clogging, EV loss | [46] |
| Size-Exclusion Chromatography (SEC) | Porous beads separate particles by size: EVs (larger than pores) elute first, while smaller molecules are delayed | Moderate–High | High | Gentle, preserves integrity | Dilution, limited volume | [47] |
| Immunoaffinity Capture | Antibodies or ligands bind specific EV surface markers to pull down target EV subpopulations (often on magnetic beads) | Low (only marker-positive EVs captured) | Very High | Specific | Costly, limited yield | [39] |
| Microfluidic Isolation | Miniaturized chip devices integrating size-based, affinity, or acoustic separation to sort EVs from small samples | Low–Moderate (small sample input) | Moderate | Rapid, small sample input | Low scale, device-dependent | [48] |