Capillary-Mediated Single-Cell Dispenser

Single-cell manipulation, sorting, and dispensing into multiwell plates is useful for single-cell multiomics studies. Here, we develop a single-cell dispenser inspired by electrohydrodynamic jet printing that achieves accurate droplet generation and single-cell sorting and dispensing using fused silica capillary tubing as both the optical detection window and nozzle for droplet dispensing. Parameters that affect droplet dispensing performance—capillary inner and outer diameter, flow rate, applied voltage, and solution properties—were optimized systematically with COMSOL simulations and experimentation. Small (5–10 nL) droplets were obtained by using 100-μm inner diameter and 160-μm outer diameter capillary tubing and allowed efficient encapsulation and dispensing of single cells. We demonstrate an application of this easy-to-assemble single-cell dispenser by sorting and dispensing cells into multiwell plates for single-cell PCR analysis.