Pipettes are widely used in clinical laboratories because of their simple basic structure and ease of use. Its basic structure mainly includes several parts, such as display window, volume adjustment part, piston, O-ring, suction tube and suction head (liquid suction nozzle).
working principle
The design of commonly used clinical micropipettes is based on Hooke's law: that is, the length of the spring extension is proportional to the elastic force within a certain limit, that is, the volume of liquid in the pipette is proportional to the elastic force of the spring in the pipette. There are two physical principles of micropipette dispensing: dispensing with an air cushion and dispensing with positive displacement of the piston without an air cushion. These two micropipettes with different principles have different specific application ranges.
Common classification
According to the working principle, it can be divided into air displacement pipettes and positive displacement pipettes; according to the number of tips that can be installed at the same time, it can be divided into single-channel pipettes and multi-channel pipettes;
According to whether the scale can be adjusted, it can be divided into fixed pipettes and adjustable pipettes;
According to the adjustment scale, it can be divided into manual pipette and electric pipette;
According to special purposes, it can be divided into fully sterilized pipettes, large-capacity pipettes, bottle-top pipettes, continuous injection pipettes, etc.