Patent ID: 7776268

Claim:
A fluidic system for pumping sheath fluid and sample fluid into an interrogation zone of a flow cytometer, comprising: a sheath pump that pumps sheath fluid from a sheath container into an interrogation zone; 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; wherein the sheath pump and the waste pump cooperate to draw sample fluid from a sample container through the drawtube into the interrogation zone; a user interface that receives, from a user, an input selected from the group consisting of: desired core stream diameter, core stream fluid type, and estimated sample particle size; 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 user interface and to the pressure sensor, wherein the controller is configured to adjust the flow rate of the sample fluid from the sample container through the drawtube into the interrogation zone, based on the user input and the measured pressure differential.