Figure 2

Efficiencies of on-chip target cell capture, release and purification.

(A) Cell-capture efficiencies of ~200 EpCAM-positive HCT116 cells spiked in 1.0-ml of PBS, lysed blood and whole blood by herringbone chips at the flow rate of 1 mL/h. Error bars show standard deviations (n = 3). (B) Generic concept of on-chip cell capture strategies. (C) Three-color immunocytochemistry method based on PE-labeled anti-pan-CK, FITC-labeled anti-CD45 and DAPI nuclear staining was applied to identify and enumerate CTCs from whole blood after on-chip cell capture. (D) Representative images of isolated CTCs from lung cancer patient #1’s blood sample stained with antibodies against cytokeratin (red), CD 45 (green) and DAPI (blue). (E) On-chip release efficiency and cell viability by various releasing approaches. (F) Numbers of RBCs and WBCs non-specifically bound on the herringbone chip after on-chip capture, released together with HCT116 cells after UV irradiation and after two-step purification to deplete blood cells. (G) Cell recovery under different number of spiked tumor cells as inputs. (H) Three-color immunocytochemistry method based on PE-labeled EpCAM, FITC-labeled CD44 and DAPI nuclear staining was applied to identify EpCAM⁺CD44⁺ and EpCAM⁺CD44^- cells.