The invention relates to a nozzle for flow cytometry, the housing of which is tapering towards an outlet and in which a feed tube is arranged for a core flow liquid, the outlet opening of which is arranged at a distance from the outlet of the housing. The outlet of the housing forms the outlet of the nozzle. The housing of the nozzle extends from its outlet, which is arranged at its first end to its opposite second end, and has an inlet for a sheath flow liquid connected with the internal volume. The nozzle is characterized in that in the housing a leading element that promotes the alignment of particles extends from both sides of the feed tube.