Pipettes are single-channel micropipettes commonly used in biological and chemical laboratories for small-volume transfer. The pipette has the characteristics that it can be calibrated by the user without the aid of tools, and is easy to disassemble and maintain. At the same time, it is fully ergonomic. The pipette has five modes: pipetting mode, sample mixing mode, reverse aspiration mode, electrophoresis loading mode, and graded pipetting mode. The pipette can be applied to liquids such as high-viscosity liquids, liquids with high vapor pressure, and foaming liquids. Pipettes are widely used in clinical diagnostic laboratories, biotechnology laboratories, pharmacy and chemistry laboratories, environmental laboratories, food laboratories.
Generally speaking, there are two types of pipettes, one is the air displacement type, which uses a built-in gas piston. The piston is designed inside the pipette and relies on pushing the air for liquid suction and discharge, and the piston does not directly contact the liquid. , the pipette referred to is the air displacement pipette; the other is the external piston type, which is often used as a special pipette, using an external piston, the piston is designed inside the tip, directly in contact with the liquid, suitable for The operation of liquids with relatively high viscosity or easy generation of bubbles is used by the dispenser in conjunction with the dispensing head, and the application range is relatively narrow. The so-called air displacement type means that the piston is pressed down, and the air inside the lower end of the pipette is pressed out. Then when the piston moves up, the air pressure inside the lower end of the pipette is less than the external air pressure, so that under the action of the external air pressure, it can be sucked up the liquid. In short, air goes out and liquid comes in. The so-called external piston type, in fact, is exactly the same as the principle of the syringe. After seeing the working process of the syringe, you can probably understand the principle of the external piston type.
The original pipette could not adjust the range, so it was called a fixed-volume pipette. Later, a pipette appeared, the range can be adjusted, but the optional range is relatively small. That is to say, with this pipette, the volume of liquid you can transfer can be selected between several gears, which is much more convenient than the original pipette.