Dean Flow Fractionation (dff) Isolation of Circulating Tumor Cells (ctcs) from Blood

Isolation and enumeration of circulating tumor cells (CTCs) as cancer biomarkers have been challenging due to their extremely low abundance in blood. This paper reports an ultra high-throughput technique for CTCs isolation from blood using the inherent Dean vortex flows present in curvilinear channels, aptly termed Dean Flow Fractionation (DFF). Using a 2-inlet 2-outlet spiral microchannel, the separation principle exploits the difference in cell size between CTCs (~16-20 μm diameter) and other blood cells (RBCs ~8 μm; leukocytes ~8-14 μm). Experimental results confirm >99% RBCs and leukocytes removal from blood sample (20% hematocrit) spiked with MCF-7 cells with >90% tumor cell recovery after separation. The developed technique offers large sample processing capability due to its ability to process very high hematocrit samples (20%), a key requirement for isolating rare-cells. A single device can process 1 mL whole blood in a single step, under 15 min.