NOMA: a high-throughput microchip for robust, sequential measurements of secretions from the same single-cells

Lacking simple methods to keep the live single-cells traceable for longitudinal detection reliably poses a significant obstacle in single-cell secretion analysis technologies. Here we developed the high-density NOMA (narrow-opening microwell array) microchip that realized the retention of ≥97% of trapped single cells in dedicated spatial locations during repetitive detection procedures, verified with both adherent and suspension cells by two researchers independently. We demonstrated its use to decode the correlation of protein abundance between secreted extracellular vesicles (EVs) and donor cells. We revealed that these two were poorly correlated with each other at the same single-cell level. We further applied it in monitoring single-cell protein secretions sequentially from the same single cells, and we found the digital protein secretion patterns dominate the protein secretion. We also demonstrated the microchip for longitudinally tracking IL-8 and the CD81+EV secretions from the same single-cells over days, which revealed the presence of “super secretors” within the cell population be more persistent to secrete protein or extracellular vesicle for an extended period. The NOMA platform reported here is simple, robust, and easy to operate for tracking sequential measurements from the same single cells, representing a novel and informative tool to inspire new observations in biomedical research. ![Figure][1] ### Competing Interest Statement The authors have declared no competing interest. [1]: pending:yes