Microfluidic platforms for capturing circulating tumor cells

We present the results of a simple, low-cost microfluidic device that can be used to isolate and capture circulating tumor cells (CTCs) from whole blood. The device was made from polydimethylsiloxane (PDMS) consisting of a microfluidic channel with microposts coated with ligand proteins. A total of 32 devices were designed, each containing different patterns in terms of shape, size, spacing, and arrangement of the microposts. The microposts were coated with anti-epithelial-cell adhesion molecule (anti-EpCAM) that has been extensively used in isolating CTCs from blood [1 - 4]. After flowing the blood sample through the devices, the captured cancer cells were quantified with optical microscopy. A comparative study of the capture efficiencies of the devices was performed based on the micropost features and sample flow rates. It was found that microposts with circular or square cross sections performed significantly better than triangular ones. Also, 100 μm posts arranged in an offset array with 50 μm gap was better than other designs in this study, reaching a capture efficiency of almost 50%.