Multiplex and Spatiotemporal Detection of Single-Cell Antibody Secretions Using Protein-Patterned Microwells.

Antibodies (Abs) are pivotal components in a myriad of applications including therapeutics and diagnostics. To discover novel target-specific Abs, screening and isolating Ab-expressing cells have proven to be an interesting route. Nevertheless, current single-cell technologies still come with some limitations, as they, for example, do not enable combined temporal and multiplex screening. To overcome these limitations, we present a microwell-based microfluidic device that enables in-depth analysis of Ab-secreting cells. By micropatterning several proteins of interest onto specific regions of the wells, we were able to: (i) investigate single cells' secretion profiles over time, and (ii) identify cells secreting Abs of interest against different proteins simultaneously. This was shown for hybridomas secreting Abs against either the receptor binding domain or the nucleocapsid of the SARS-COV-2 virus. Moreover, our strategy is easily adaptable to a wide range of secretome studies as it enables the patterning of different proteins of interest (e.g., ligands and cell-adhesive proteins) and thus shows great promise for applications across numerous fields, including fundamental (e.g., cell-cell communication) and applied (e.g., drug discovery) research.