High-Throughput Selection, Enumeration, Electrokinetic Manipulation, and Molecular Profiling of Low-Abundance Circulating Tumor Cells Using a Microfluidic System

作者：Udara Dharmasiri, Samuel K. Njoroge, Małgorzata A. Witek, Morayo G. Adebiyi, Joyce W. Kamande, Mateusz L. Hupert, Francis Barany, Steven A. Soper · 发表于：Analytical Chemistry · 年份：2011 · DOI：10.1021/ac103172y · 被引用次数：180 · 研究领域：Microfluidic and Bio-sensing Technologies、Microfluidic and Capillary Electrophoresis Applications、Cancer Cells and Metastasis

A circulating tumor cell (CTC) selection microfluidic device was integrated to an electrokinetic enrichment device for preconcentrating CTCs directly from whole blood to allow for the detection of mutations contained within the genomic DNA of the CTCs. Molecular profiling of CTCs can provide important clinical information that cannot be garnered simply by enumerating the selected CTCs. We evaluated our approach using SW620 and HT29 cells (colorectal cancer cell lines) seeded into whole blood as a model system. Because SW620 and HT29 cells overexpress the integral membrane protein EpCAM, they could be immunospecifically selected using a microfluidic device containing anti-EpCAM antibodies immobilized to the walls of a selection bed. The microfluidic device was operated at an optimized flow rate of 2 mm s(-1), which allowed for the ability to process 1 mL of whole blood in <40 min. The selected CTCs were then enzymatically released from the antibody selection surface and hydrodynamically transported through a pair of Pt electrodes for conductivity-based enumeration. The efficiency of CTC selection was found to be 96% ± 4%. Following enumeration, the CTCs were hydrodynamically transported at a flow rate of 1 μL min(-1) to an on-chip electromanipulation unit, where they were electrophoretically withdrawn from the bulk hydrodynamic flow and directed into a receiving reservoir. Using an electric field of 100 V cm(-1), the negatively charged CTCs were enriched into an anodic receivi...