Table 1.

Advantages and disadvantages of affinity-based and label-free isolation [17, 117, 118]

	Advantages	Disadvantages
Affinity-based isolation	Highly specific High purity of CTCs Application of the combination of antibodies allow to capture cells with epithelial and mesenchymal phenotype Capture of CTC clusters Separation/categorization based on abundance of Ep-CAM expression	Limitations in velocity and flow Blood volume Decrease of cell viability during the detachment process High cost of antibodies Low capture efficiency
Label-free isolation	High-throughput Allow CTCs capture regardless of subpopulation differences and EMT process Allow further cell molecular characterization Allow cell culturing and further recovery in suspension Allow preservation of cell clusters to study their metastatic ability Low cost	Capture depends on size pores Overlapping in CTCs and leucocytes sizes Pores clogging Low sample purity Low CTCs recovery