Abstract: The present application discloses a system and a method for calculating a droplet delay time in a liquid flow of a sorting device. The system includes: a first laser source configured to emit a first laser beam to a liquid flow of a sorting device, the first laser beam and the liquid flow intersecting at a first laser interrogation point; a second laser source configured to emit a second laser beam to the liquid flow, the second laser beam and the liquid flow intersecting at a second laser interrogation point; and a droplet delay time calculation unit configured to calculate, based on of the time when the particle in the liquid flow passes through the first and second laser interrogation point and the time when the particle passes through the second laser interrogation point, a first delay time, and calculate, a droplet delay time.

Abstract: The present application discloses a system and a method for calculating a droplet delay time in a liquid flow of a sorting device, and a sorting device.

Abstract: An optical illumination and monitoring subsystem controls the operation of a flow cytometer having a carrier fluid that flows along a channel coupled to a droplet generator, which controls a point at which droplets break off from the carrier fluid, and a droplet sorter that is operative to cause selected droplets to be sorted along one or more droplet travel paths. The subsystem is operative to illuminate a respective droplet monitoring location along each of one or more droplet travel paths with a respective beam of light, such as that sourced from a common laser. In response to backscatter reflection from a droplet passing through the respective beam of light at a respective droplet monitoring location, the amplitude of the beam of light is increased. Then the droplet is monitored for the presence of a particle therein exhibiting detectable fluorescence as a result of the increase in the amplitude of the respective beam of light.

Abstract: A droplet travel path monitoring mechanism for a flow cytometer is operative to adjust the droplet break-off point back to an initially calibrated spatial location, in the event of the departure from calibrated timing of gaps in the unsorted fluid droplet stream that have been created by the deflection of charged droplets. In addition, the flow cytometer is operative to monitor prescribed characteristics of deflected droplet streams, and to controllably adjust drop-sorting deflection parameters, so as to maintain the deflected travel path of sorted droplets coincident with the opening into a sorted droplet collection container, thereby maximizing collection of all sorted droplets.