Research on Automatic Micro-volume Liquid Pipetting Device in Flow Cytometer

Flow cytometry is a kind of in vitro diagnostic instrument widely used for cell detection. Its sample pretreatment involves the marking, incubation, cleaning, mixing and other steps of antigen or antibody. Due to the inevitable human error and antibody loss phenomenon in the detection process, in order to reduce all kinds of waste caused by human error and improve the sample processing efficiency, it is an inevitable trend to introduce automatic sample pretreatment system which is depending on the precision and repeatability of micro-volume liquid pipetting device. The micro-volume liquid pipetting device designed in this paper is composed of manipulator control system, liquid path control and electric control system, within the pitetting range of 20$\mu 1-500\mu 1$, the accuracy is about $0.1\mu 1$, the coefficient of volume variation (CV) is less than 2%. The liquid level sensing has been improved for the application of flow detection of automatic micro-volume liquid pipetting.