UC San Diego

The ability to identify, characterize and isolate cancer cell subpopulations from a global cell population is important and fundamental for effective cancer diagnostic treatments. Cells that have shed from a primary tumor site at early stages of malignant progression and then enter the blood circulation are called circulating tumor cells (CTC). Although only a small percentage of CTC survive (roughly 0.05%), the detection of these cells provides an excellent indicator of metastatic primary tumor sites. The necessity for effective measurement of CTC requires engineering a standardized detection method capable of processing whole blood samples. An alternative method to cell selection is the alternating current (AC) electrokinetic technique, dielectrophoresis (DEP), which employs the use of alternating current (AC) fields to separate cells. Previous studies have confirmed the diagnostic ability of identification and separation of live cells from dead ones using DEP. A novel approach utilized to kill explicit cell lines in order to perform DEP separations of live and dead cells, employs a developed theory that tumor microenvironments are more acidic than normal microenvironments. By combining the selection of cancer cells from normal cells through pH control and subsequently separating these cells using dielectrophoresis an effective circulating tumor cell detection system can be produced