Phenotypic Characterization and Sorting of Circulating Tumor Cells (CTCs) Using a Digital Image-Based Sorter

Circulating tumor cells (CTCs) are rare cells found in the bloodstream of patients with solid tumors, originating from the primary tumor and migrating toward distant anatomical sites. Recognized as key agents in the metastatic process, CTCs are essential to study in order to understand the underlying mechanisms of metastasis. However, CTC analysis is challenging due to their extreme rarity in the bloodstream (approximately one CTC per 10⁶-10⁷ white blood cells). Dielectrophoretic (DEP)-based digital imaging and sorting technology enables the visualization and isolation of single, labeled cells within heterogeneous samples, making it invaluable for investigating rare cells like CTCs. This book chapter reviews methods for CTC enrichment, digital visualization, phenotypic profiling, and downstream analysis following DEP-based procedures.