System, including methods, apparatus, and kits, for forming emulsions. The system may include an instrument and a microfluidic chip received by the instrument. The instrument may apply pressure to prospective emulsion phases held by the chip, to drive formation and collection of emulsions in the chip. In some embodiments, the instrument may stop applying pressure to the chip when a change in pressure meeting a predefined condition is detected by the instrument. The change may indicate that an endpoint of droplet generation has been reached.