Abstract: In one example in accordance with the present disclosure, am ejection system is described. The ejection system includes a fluid feed slot to supply fluid to a number of fluid ejection channels where each fluid ejection channel is a recirculating channel. Each fluid ejection channel includes a sensor to detect, in the fluid, a target particle to be ejected and a fluid ejector to eject the target particle from the fluid ejection channel. The ejection system also includes a controller to selectively activate the fluid ejector when the target particle presence is detected. Non-target particles are returned to the fluid feed slot past the fluid ejector.

Abstract: In one example in accordance with the present disclosure, a fluid ejection die is described. The fluid ejection die includes a fluid feed slot to deliver fluid from a reservoir to an array of ejection chambers fluid connected to the fluid feed slot. Each ejection chamber includes at least one fluid actuator and an opening through which fluid is to be ejected. The fluid ejection die also includes a number of antechambers. An antechamber includes sidewalls that curve inward.

Abstract: A microfluidic dispenser can include a processor to receive a user input via a user interface related to limiting dilution (or a limiting dilution assay) to be performed, and calculate a dispense volume of a fluid for the limiting dilution based on the user input. The microfluidic dispenser can also include a dispense cassette including a fluid reservoir, and a microfluidic dispense head to dispense the fluid via a nozzle in accordance with the calculated dispense volume.