Patent ID: 8187888

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, wherein the sheath pump and the waste pump cooperate to draw sample fluid from the sample container into the interrogation zone; a first fluidic capacitor, located between the sheath pump and the interrogation zone, that temporarily expands and accumulates sheath fluid to attenuate pulsations within the sheath fluid; a second fluidic capacitor located between the interrogation zone and the waste container and that temporarily expands and accumulates the waste fluid to attenuate pulsations within the waste fluid; a drawtube, coupled to the sample container, that conveys the sample fluid from the sample container to the interrogation zone; a pressure sensor that measures a pressure differential of the sample fluid between the top of the drawtube and the bottom of the drawtube; and a controller, coupled to the pressure sensor, that adjusts the flow rate of the sample fluid from the sample container into the interrogation zone by controlling at least one of the flow rates of the sheath fluid and the waste fluid.