Circulating Tumor Cells in Gastrointestinal Malignancies: Current Techniques and Clinical Implications

Table 1

Common techniques for CTC-enrichment and detection. MACS (Magnetic Activated Cell Separation), ISET (Isolation by Size of Epithelial Tumor Cells), FISH (Fluorescent in Situ Hybridization), RT-PCR (Reverse Transcription Polymerase Chain Reaction).

System	Blood volume per test (mL)	Time for enrichment (minute)	Principle of CTC enrichment and detection	Sensitivity	Reference
OncoQuick	15–35 mL	45 minutes	Cellular density gradient, immunolabeling	1 cell/4.5 uL	[31, 34]
MACS	5–15 mL	120 minutes	Capture by immunobeads, immunolabeling and FISH or RT_PCR	1 cell/0.3 uL	[35]
CellSearch	7,5 mL	40 minutes	Capture by immunobeads (negative selection by CD-45; positive selection by CK-8, -18, -19)	1 cell/0.5 uL	[33, 36]
ISET	10 mL	15 minutes	Direct filtration and immunolabeling	1 cell/mL	[37]