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 (DEP) 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, DEP 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 Gal-3 binding protein (Gal-3bp) 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.