The disclosure provides example rinse station apparatus, cartridges, and methods for flow cytometry. The rinse station apparatus includes: (a) a cartridge docking station having a base with a recessed receptacle for a cartridge, a vertical support coupled to the base's first end and a top support coupled to the vertical support and cantilevered over the base, the top support has an opening that aligns with the cartridge's opening, (b) a locking arm coupled to the base's second end, the locking arm's free end has a ridge to cooperate with a detent coupled to the cartridge's rear wall to retain the cartridge in place, (c) a spring coupled to the vertical support's front face to apply force to the cartridge's front wall to bias the cartridge toward the locking arm, and (d) a load cell coupled to the base of the cartridge docking station, the load cell measure's the cartridge's weight.