A system including a communication interface to communicatively couple to a sensor cartridge, a fluidic subsystem to exchange a reagent solution with the sensor cartridge, and a computational circuitry communicatively coupled to the communication interface and the fluidic subsystem. The computation circuitry is to monitor a sensor signal of a sensor of the sensor cartridge, detect a leak based on the sensor signal, and control fluid flow of the fluidic subsystem in response to detecting.