Table 1.
Examples of detection technologies for CTCs in peripheral blood and DTCs in bone marrow.
| Enrichment approach | Technology | Source | Primary enrichment | Secondary CTC/DTC detection technique and identification markers | Comments |
|---|---|---|---|---|---|
| Immunological | CellSearch® by Veridex | Blood (7.5 ml) | EpCAM-labeled ferrofluids | Immunocytochemistry: CK (8/18/19), CD45, DAPI (nuclear staining) | Semiautomated system; FDA-approved for stage IV breast, colon and prostate cancers |
| AdnaTest® | Blood (7 ml) | Immunomagnetic (EpCAM, MUC-1, Her2) | Multiplex PCR: Twist, Akt2, PI3Kα | Detection of epithelial, mesenchymal and stem cell features | |
| EPISPOT assay | Blood, BM (10 ml) | Immunomagnetic (depletion of CD45- cells) | Culture & Immunocytochemistry: CK19, MUC1, Cath-D (breast); CK19 (colon); PSA (prostate); TG (thyroid) | Detection of viable, secreting CTCs/DTCs | |
| PowerMag® | Blood (5 ml) | Dextran-coated magnetic nanoparticles: depletion of CD45+ cells | Immunocytochemistry: EpCAM | Detection technique is comparable to FDA-approved CellSearch® system | |
| Size | ISET® (Isolation by Size of Tumor cells) | Blood (5 ml) | Filter | Cytology & Immunocytochemistry: haematoxylin, CK | High sensitivity |
| FSMA (flexible spring microarray) | Blood (7.5 ml) | 3-dimensional microfilter | Immunocytochemistry: CK | High sensitivity, mesenchymal and stem cell markers can be stained, allows culturing | |
| Density | Oncoquick® | Blood (15 ml) | Density gradient centrifugation | Immunocytochemistry: CK | Allows different additional analysis (immunocytochemistry, rt-PCR, cell culture, cell sorting) |
| Ficoll-Paque | BM (15 ml) | Density gradient centrifugation | Immunocytochemistry: CK | Traditional technique for purification of DTCs from bone marrow | |
| Electrophoresis | ApoStream® | Blood (7.5 ml) | Dielectrophoretic forces | Immunocytochemistry: EpCAM, CK | Cells can be cultured |
| Microscopy | Epic Sciences® | Blood (10 ml) | RBC lysis, centrifugation | Immunocytochemistry: CK | Automated scanning system, EpCAM-independent, CTCs are identified on marker expression and morphology |
BM: bone marrow; EpCAM: Epithelial cell adhesion molecule; CK: Cytokeratin; RBC: Red blood cell.