Automated centrifugal microfluidic platform for label-free separation and lysis of cancer cells from whole blood.

Isolating and identifying circulating tumor cells (CTCs) from peripheral blood presents a promising avenue for early cancer diagnosis, metastasis prevention, and timely therapeutic intervention. However, most current isolation techniques are costly, labor-intensive, and require complex labeling procedures. To address these problems, this study introduces a cost-effective and fully automated centrifugal microfluidic platform for the label-free separation and subsequent lysis of cancer cells from whole blood samples. The separation unit comprises a Y-shaped inlet, trapezoidal contraction-expansion array (CEA) microchannel, and bifurcated outlet, which collectively enhance the separation efficiency by harnessing four key hydrodynamic forces: the centrifugal force, Coriolis force, inertial lift force, and Dean drag force. Following the separation process, the disc rotation speed is increased to drive the cells through a serpentine mixing channel, where they mix with a lysis buffer and then flow into a collection chamber. Numerical simulations are performed to evaluate the fluid flow and particle behavior within the separation channel and lysis micromixer. Experiments are then conducted with K562 leukemia cells spiked into blood samples with different hematocrit levels. A peak separation efficiency of 91.8 % is obtained at a disc rotation speed of 2250 rpm. Moreover, the mixing performance reaches 94.8 % at 2750 rpm. The entire sample loading, cell separation, mixing, decanting, and lysis process is completed within two minutes. Thus, the proposed device shows significant potential as a rapid, user-friendly, and scalable solution for point-of-care cancer diagnosis.