Data from: Deterministic cell pairing with simultaneous microfluidic merging and sorting of droplets

Cell–cell interactions drive immune activation, tissue repair, and stem
cell fate, yet there are few methods that can create large numbers of
pre-defined cell pairs to study cell crosstalk. Droplet microfluidics
allows high-throughput compartmentalization of multiple cells, but random
loading results in < 1 % of droplets containing the desired
combinations. Here, we present Pair Isolation by Coalescence and Sorting
(PICS), a microfluidic platform that can generate specific cell pairs
through droplet merging and sorting (‘merge-sorting’). PICS detects target
combinations using fluorescence and triggers simultaneous
electrocoalescence and dielectrophoretic sorting. Using fluorescent
dye–loaded droplets, we achieved 98.6 % purity of merged and sorted
droplets. In experiments using cells stained with three distinct dyes,
> 90 % of desired cell pairs were recovered – compared to fewer
than 1 % when using random Poisson loading. To demonstrate the utility of
PICS for extended co-culture studies, we merged cells in an alginate
solution with calcium chloride droplets, producing monodisperse alginate
hydrogels in which 93.3 % of the beads contained target cell pairs that
maintained viability over 18 hours. Compared to selective merger, this
approach physically isolates desired droplets, eliminating unmerged
contaminants and enabling cleaner downstream workflows. PICS allows
off-chip pre-incubation of droplets before pairing, the merger of reagents
for multi-step assays, and the rapid isolation of desired droplet pairs –
capabilities not jointly accessible with existing approaches. In summary,
PICS is a flexible platform to enrich specific combinations of droplets,
cells, or particles for high-throughput studies of cell crosstalk.