Abstract: We describe instruments, and cartridges therefor, for processing droplets of water in oil-in-water emulsions, the droplets containing biological entities such as cells. In one embodiment a method of such processing comprises: providing a plurality of the entities in a fluid: preparing a droplet from said fluid: determining whether said droplet contains one or more entities of said plurality of entities, or whether said droplet does not contain a said entity; sorting said droplet dependent on an outcome of said determination; and dispensing said sorted droplet into a reservoir, wherein said dispensing comprises: identifying said sorted droplet for dispensing; extracting said sorted droplet from a first fluidic flow path of said fluid by transferring said sorted droplet from said first fluidic flow path into a second fluidic flow path; and ejecting said sorted droplet from said second fluidic flow path into said reservoir by applying pressure to said second fluidic flow path.