Efficient separation of tumor cells from untreated whole blood using a novel multistage hydrodynamic focusing microfluidics.

Significant progress on circulating tumor cells (CTCs) has profound impact for noninvasive tumor profiling including early diagnosis, treatment monitoring, and metastasis recognition. Therefore, CTCs based liquid biopsy technology is taking a rapid growth in the field of precision oncology. The label-free approaches relied on microfluidic chip stand out from a crowd of methods that suffer from time consuming, extensive blood samples, lost target cells and labor-intensive operation. In this paper, a label-free separation microfluidic device was developed using multistage channel, which took full advantage of inertial lift force. Our strategy demonstrated CTCs were efficiently isolated from untreated human blood samples including antibody conjugation and erythrocyte lysis. This device was applied for isolating human brain malignant glioma cells that were spiked in human peripheral blood samples. The experimental condition was optimized and exhibited an average separation efficiency of ≥ 90% across cell morphological analysis, up to 84.96% purity of collected CTCs and the viability of all cells is >95%, which was better than other one-step CTCs separation methods. Furthermore, the CTCs were successfully separated from untreated clinical blood sample of cancer patient on the proposed microfluidic device. The entire experimental procedures are extremely low-cost and easy manipulation. It is believed that the proposed multistage microfluidic chip can become a promising tool for CTCs separation and early diagnosis of cancer.