On-chip circulating tumor cells isolation based on membrane filtration and immuno-magnetic bead clump capture

Abstract

Isolating rare circulating tumor cells (CTCs) from blood is critical for the downstream analysis that is important in cancer-related research, diagnosis, and medicine, and efforts are ongoing to increase the efficiency and purity of CTC isolation in microfluidics. Reported in this paper is a two-stage integrated microfluidic chip for coarse-to-fine CTC isolation from whole blood. First, blood cells are removed by filtration using a micropore-array membrane, then CTCs and other cells that are trapped in the micropores are peeled off the membrane by a novel release method based on air–liquid interfacial tension, which significantly increases the recovery rate of CTCs. The second stage is CTC capture based on an on-chip dense immuno-magnetic-bead clump, which offers high capture efficiency and purity. Both the micropore filtration and immuno-magnetic-bead capture are validated and optimized experimentally. Overall, the integrated microfluidic chip can realize a recovery rate of 85.5% and a purity of 37.8% for rare cancer cells spiked in whole blood.