Label-free enumeration of colorectal cancer cells from lymphocytes performed at a high cell-loading density by using interdigitated ring-array microelectrodes

• Published in: Biosensors & bioelectronics Vol. 61; pp. 434 - 442
• Main Authors: Xing, Xiaoxing, Poon, Randy Y.C., Wong, Cesar S.C., Yobas, Levent
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.11.2014; Elsevier
• Subjects: Arrays; Biological and medical sciences; Biosensing Techniques - instrumentation; Biotechnology; Blood; Cancer; Cell Count; Cell Line, Tumor; Cell Separation - instrumentation; Cells; Colorectal Neoplasms - blood; Colorectal Neoplasms - pathology; Density; Dielectrophoresis; Electrode; Electrophoresis - instrumentation; Enumeration; Equipment Design; Fundamental and applied biological sciences. Psychology; Humans; Lymphocytes; Lymphocytes - cytology; Microelectrodes; Microfluidic Analytical Techniques - instrumentation; Microfluidics; Neoplastic Cells, Circulating - pathology; Silicon; Three dimensional; Silicon; Electrode; Dielectrophoresis; Microfluidics; Cells; Cancer; Fluid mechanics; Enumeration; High density; Malignant tumor; Interdigitated array electrode; Enumeration(counting); Colon; Miniaturization; Lymphocyte; Tumor cell
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2014.05.054

We report the label-free enumeration of human colorectal-carcinoma cells from blood lymphocytes by using interdigitated ring-array microelectrodes; this enumeration was based on the dielectrophoretic selection of cells. Because of the novel design of the device, a continuous flow of cells is uniformly distributed into parallel streams through 300 rings (~40μm in diameter each) that are integrated into the electrode digits. Using this array, 82% of cancer cells were recovered and 99% of blood lymphocytes were removed. Most of the cancer cells recovered were viable (94%) and could be cultivated for >8 days, during which period they retained their normal cell morphology and proliferation rates. The recovery rate correlated closely with cancer-cell loadings in spiked samples and this relationship was linear over a range of at least 2 orders of magnitude. Importantly, because of the 3D structure of the rings, these results were obtained at a high cell-loading concentration (107cells/mL). The rings could be further optimized for use in accurate label-free identification and measurement of circulating tumor cells in cancer research and disease management. •A novel design for label-free enumeration of cancer cells from lymphocytes is shown.•The design engages dielectrophoresis through interdigitated ring array microelectrodes.•This unique design enabled the use of a high-cell loading density (107cells/mL).•Nearly 82% of cancer cells were recovered and 99% of lymphocytes were removed.•Recovered cells (94%) were viable and their morphology and proliferation were normal.