Isolation and elution of Hep3B circulating tumor cells using a dual-functional herringbone chip

Circulating tumor cells (CTCs), which are derived from primary tumor and circulate to secondary site, are regarded as the cause of metastasis. Many methods have been applied for CTC isolation and enumeration so far. However, it remains a challenge to effectively elute the captured cells from the device for further cellular and biomolecular analyses. In this paper, we fabricate a dual-functional herringbone chip to achieve both CTC capture and elution based on the immunoassay of epithelial cell adhesion molecule antigen expressed on the surface of human liver cancer cell line Hep3B. The results show that the capture limit of Hep3B cells can reach as low as 3 cells per ml with capture efficiency over 50 % on average. On the other hand, the elution rate of more than 50 % of the captured Hep3B cells can be achieved for cell density ranging from 5 to 2 x 10(3)/ml. It demonstrates that this herringbone chip exhibits excellent dual functions with high capture efficiency and considerable elution rate, indicating its promising capability for clinical assay in cancer diagnosis.