TABLE II.
Methods for microfluidic isolation of CTCs and clusters.
| Principle | Efficiency | Purity | Throughput | Advantages | Disadvantages | |
|---|---|---|---|---|---|---|
| Sized-based trapping | Hydrodynamic capture through microwells92,93 and micropost trapping51 | ∼40–99% (Increased efficiency with increasing cluster size) | ⋯ | 200 ml/min, −2.5 ml/h | High-efficiency, label-free | Low-throughput, low purity, and low specificity |
| Sized-based flow separation | Deterministic lateral displacement (DLD),4 shear-induced diffusion (SID),50,72 and inertial focusing3,67–69,73 | ∼37%–99% | 57%–94% | 0.2–0.5 ml/min | High-throughput, high-efficiency, label-free | Low specificity, low-mid purity |
| Marker-dependent | Antibody1,58,75,76,141 and nanoparticle59 coated surfaces | ∼60%–98% | ∼14%–86% | 1–2.5 ml/h | High specificity | Low throughput, low purity, low efficiency, difficult to retrieve cells |
| Active | Capture through optical,83 magnetic,84 acoustic,78,79,82, and dielectrophoretic83,85 | ∼71%–90% | 84%–91.5% | 1.2–30 ml/h | High purity, minimized shear force, label-free | High efficiency, low throughput, complex setup |