Automated, Label-free Analysis of Rare, Large Cells from Blood

Cancer cells found in circulation, termed circulating tumor cells (CTCs), are believed to disseminate from tumors and form secondary metastatic sites. These malignant cells may provide a crucial source to characterize and monitor malignancy but they exist among billions of blood cells and are extremely rare (1-500 CTCs/mL blood). Developing isolation and analysis methods rely on antibodies targeted towards CTC surface markers but their heterogeneous expression indicates the need for alternative methods of analysis that correlate more with malignancy.We use a recently introduced microfluidic device that can selectively isolate and concentrate large (> 15 micrometers) cells from blood. The label-free and high-purity isolation achieved enables passive analysis of the isolated cells, which can give a quick readout about the suitability for further downstream assays. Correlating label-free characteristics of CTCs to disease state may provide more accurate clinical information for cancer diagnosis, treatment monitoring, and personalized therapy identification