Fig. 1.

Design and operation of the Metas-Chip. a The system captures and diagnoses metastatic cells from the unprocessed CNB or FNA sample derived from the lymph of any suspicious secondary tissue, based on their active interaction by single vascular traps and retraction of the trap due to invasion of metastatic cell. This sharply reduces the electrical resistance of the sensing region. b Image of a working Metas-Chip with complete accessories (b1) including multiple rows of microelectrodes selectively covered by single HUVECs that form consecutive traps for metastatic cells, electrical interfacial boards and matching optical-electrical measurements subsystem (b2); sentinel lymph sample of a patient (b3) is held on the inlet without any processing (b4). High-magnification optical-capturing system takes live images from any interaction between single traps and probable detached cells from the sample (b5). b6 shows the software user interface (UI) of Metas-Chip, which include the microscopic image of sensing region with the micro-electrical traps collection networks in live matching by time-dependent electrical diagrams of all sensing traps. Occurrence of metastatic interaction would be recognized and presented by the system. The size of the main detecting chip is 0.5 × 0.5 cm². c To prepare the chip for detection of metastasis, single HUVECs selectively covered each electrical trap by dielectrophoretic process (electrostatic driving force biased on the system). The scale bars are 25 µm in length