The pipette is a small-volume single-channel micropipette commonly used in biological and chemical laboratories. The pipette can be calibrated by the user without the aid of tools, and is easy to disassemble and maintain. At the same time, it fully complies with the principles of ergonomics. 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, high vapor pressure liquids, and foaming liquids. Pipettes are widely used in clinical diagnostic laboratories, biotechnology laboratories, pharmacy and chemical laboratories, environmental laboratories, and 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 air to aspirate and discharge liquid. The piston does not directly contact the liquid. , The pipette referred to is the air displacement pipette; the other is the external piston type 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 For the operation of liquids with relatively high viscosity or easy to produce bubbles, the dispenser is used in conjunction with the dispensing head, and the application range is relatively narrow. The so-called air displacement type is to press down the piston to press out the air inside the lower end of the pipette, and then when the piston is moved up, the air pressure inside the lower end of the pipette is less than the external air pressure, so that it can be under the action of the external air pressure. Suck the liquid up. In short, the air goes out and the liquid comes in. The so-called external piston type, in fact, is exactly the same as the principle of the syringe. Once you have seen the working process of the syringe, you can probably understand the principle of the external piston type.
The original pipette could not adjust the volume, so it was called a fixed volume pipette. Later, a pipette appeared, the range can be adjusted, but the selectable range is relatively small. That is to say, with this pipette, the volume of liquid you can transfer can be selected among several gears, which is much more convenient than the original pipette.