Cell sorting across laminar interface using stiffness contrast

We report non-inertial lift induced sorting of metastatic breast cancer cells from Peripheral Blood Mononuclear Cells (PBMCs) across liquid-liquid interface. The interplay between lift force and interfacial tension (IFT) force governs cell migration phenomena. We demonstrated isolation of two different types of cancer cells, namely, MCF-7 and MDA-MB-231 from PBMCs and quantify our sorting results by tagging the cells with EpCAM and CD45 and using fluorescence imaging. With 102-104 cancer cells in 105-107 PBMCs, we achieved a processing rate of >25000 cells per min at a sorting efficiency of ~99%.