High-Throughput Microfluidic Labyrinth for the Label-free Isolation of Circulating Tumor Cells

We present “Labyrinth,” a label-free microfluidic device to isolate circulating tumor cells (CTCs) using the combination of long loops and sharp corners to focus both CTCs and white blood cells (WBCs) at a high throughput of 2.5 mL/min. The high yield (>90%) and purity (600 WBCs/mL) of Labyrinth enabled us to profile gene expression in CTCs. As proof of principle, we used previously established cancer stem cell gene signatures to profile single cells isolated from the blood of breast cancer patients. We observed heterogeneous subpopulations of CTCs expressing genes for stem cells, epithelial cells, mesenchymal cells, and cells transitioning between epithelial and mesenchymal. Labyrinth offers a cell-surface marker-independent single-cell isolation platform to study heterogeneous CTC subpopulations. [Display omitted] •High-throughput label-free isolation of CTCs•CTCs were isolated from 56 breast and 20 pancreatic cancer patients•Unbiased molecular study of CTCs at the single-cell level•70 isolated single CTCs show both inter- and intra-patient molecular heterogeneity High-throughput and label-free Labyrinth device that enables single CTC isolation and gene expression characterization.