sdDE-FACS: Attached are device design files for this work, in the form of orderable mask files. These files were based on device geometries featuring simple one-step flow focuser droplet generators provided from David Sukovich and Adam Abate, as acknowledged in Brower et al., Lab on a Chip, 2020 (sdDE-FACS) method. Device designs are scaled to optimize for the ultimate size of the desired droplet by inner and outer nozzle size, respectively. In AutoCAD (recommended) or another CAD program, measure the inner and outer nozzle sizes or adjust the file by scaling as desired. For fabrication, create a two-layer mold of where each component (Flow Focuser 1 or 2, respectively) is the height of the chosen nozzle size for that component. We have attached an example protocol here. Further details are described in the manuscript. Additional fabrication details for multi-layer photolithography can be found in Brower Jove (2017) as cited in the manuscript. sdDE-FACS Note: sdDE-FACS is compatible with other means of generating monodisperse double emulsions including use of commercial chips (e.g., Dolomite). We recommend use of these PDMS device designs because of ease-of-use but any method with high uniformity of droplets is acceptable. Dropception and sdDE-FACS (single cell encapsulation): Our new pre-print (here) describes single cell encapsulation using a new double emulsion generator device with a dual inlet geometry designed by our group with design elements from the prior sdDE-FACS device architecture. We recommend use of this device design for all studies involving multiple reagents or cells as uniformity of resultant droplets is high and performance in FACS is excellent. An easy step-by-step protocol is available accompanying the pre-print. Fabrication protocols are the same as above. Feel free to contact us with more questions: kbrower@stanford.edu