Patent ID: 8017402

Claim:
A fluidic system for pumping sheath fluid from a sheath container and sample fluid from a sample container into an interrogation zone of a flow cytometer, comprising: a sheath pump that pumps sheath fluid from the sheath container into the interrogation zone of the flow cytometer; a waste pump that pumps waste fluid from the interrogation zone into a waste container; a drawtube, coupled to the sample container, that conveys the sample fluid from the sample container to the interrogation zone; a motor with motor controls coupled to at least one of the pumps of the fluidic system; a first fluidic capacitor located between the sheath pump and the interrogation zone and that temporarily expands and accumulates the sheath fluid to attenuate pulsations within the sheath fluid; a controller connected to the motor that adjusts the flow rate of the sample fluid from the sample container into the interrogation zone; and a pressure sensor that measures a pressure differential of the sample fluid between the top of the drawtube and the bottom of the drawtube, wherein the controller is coupled to the pressure sensor and adjusts the flow rate of the sample fluid based on the measured pressure differential, wherein the controller adjusts the flow rate of the sample fluid by adjusting the flow rate of the sheath fluid from the sheath container to the interrogation zone while simultaneously maintaining a substantially consistent flow rate of the waste fluid from the interrogation zone into the waste container.