Picopump elite

Double emulsions were generated using 3 syringe pumps (PicoPump Elite, Harvard Apparatus) for the inner, oil, and carrier fluids. The inner phase for the aqueous droplet core was composed of Tween-20 (Sigma) in PBS (Invitrogen), with additional reagents (e.g. FITC–BSA, Invitrogen) as indicated in (Table 1). BSA (0.5–2%) can be optionally substituted for Tween-20 (0.1–1%) in the droplet core to no adverse effect. The oil phase was composed of HFE7500 (Sigma) and ionic PEG-Kyrtox teholtze-biocompatible-2008, sukovich-sequence-2017 (FSH, Miller-Stephenson). The carrier phase contained Tween-20 (Sigma) and Pluronic F68 (Kolliphor P 188, Sigma) in PBS. Each phase was loaded into syringes (PlastiPak, BD; Hamilton, Sigma, see ESI† extended methods), and connected to the device via PE/2 tubing (Scientific Commodities). Typical flow rates were 275 : 75 : 2500 (oil : inner core : outer aqueous sheath) μL h⁻¹. Droplet generation was monitored and recorded via a stereoscope (Amscope) and high-speed CMOS camera (ASI 174MM, ZWO) (Fig. S1†).

DEs were generated using 3 syringe pumps (PicoPump Elite, Harvard Apparatus) for the inner, oil, and outer carrier fluids. Syringes (1–10 mL; PlastiPak plastic syringes, BD) were connected to the microfluidic device with polyethylene tubing (PE/2, Scientific Commodities). Droplet generation rates were typically 1–10 kHz. For the initial condition (Fig. 2), the inner phase for the aqueous droplet core was composed of 1% Tween-20 (Sigma) and FITC-BSA in 1x PBS (Invitrogen). For all measurements, the oil phase was composed of HFE-7500 (Sigma) and 2.2% Ionic PEG-Krytox (FSH 157, Miller-Stephenson) and the outer phase was composed of 1% Tween-20 (Sigma) and 2% Pluronic F68 (Kluplour 188, Sigma) in PBS. Typical flow rates were 400 : 230 : 6500 (O : I : C) μL h⁻¹. Droplet generation was monitored and recorded via a stereoscope (Amscope) and high-speed CMOS camera (ASI 174MM, ZWO). Droplets were stabilized for 4 minutes prior to a set collection time of 6 minutes. At each condition, we acquired a 500-frame video to assess stability and breakoff phenotype.