Disclosed is a two station system for a flow cytometer that includes a sample station and a wash station. During washing, the user has access to the sample station to insert a new sample. This increases the efficiency of the workflow process. Rotary clamps are used to automatically clamp the sample station and wash station to the system. A low volume pressurized cavity is used to bring the pressure of the sample to a desired pressure, which further increases productivity of the system. A transparent body is provided in the sample station so a user can view the sample during the sampling process. A backwash process is used to clean the sample injection tube and the sample uptake tube. In addition, the wash station is designed to rinse the outer surface of the sample uptake tube.