A High-throughput Hybrid Electromicrofluidic Platform for Organizing Single-Cell Protein Secretion Profiling Assays

We introduce a novel hybrid microfluidic platform that utilizes hydrodynamic trapping and dielectrophoretic forces to transfer cells and particles into semi-isolate microchambers. The electromicrofluidic chip is designed to form a high-throughput single-cell assay in a massively parallel manner. In the first operational phase, hydrodynamic forces transfer single particles into trap sites. Then, in the second phase, dielectrophoretic forces transport them into adjacent low-shear microchambers. After assembling thousands of individual cells into an array of 10,000 microchambers, the chip adds single fluorescently-labeled beads sensitive to the target proteins to study the cell protein secretion profiles at the single-cell level. To show this capability, we used this multiplexed on-chip immunoassay to analyze galectin-3 (Gal-3) and galectin-3 binding (Gal-3bp) protein secretion profiles in cancer (MCF-7) and normal (HEK-293T) cells. The ability to controllably add tens of required single beads sensitive to the target proteins in this high-throughput system is an answer to the challenges in previously introduced similar devices. The proposed biomedical microdevice has great potential for running fundamental long-term single-cell phenotypic and genotypic studies, with crucial applications in biology and medicine.