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

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. (C) 2022 Author(s).

Automated summary

This paper presents an integrated microfluidic chip for isolating rare circulating tumor cells (CTCs) from whole blood. The chip consists of two stages of separation, with the first stage removing blood cells through filtration and the second stage capturing CTCs using dense immuno-magnetic-bead clumps. Both the filtration and capture methods are validated and optimized experimentally, achieving high recovery rate and purity for rare cancer cells in whole blood.