Brief introduction of pipette
The pipetting gun is a kind of pipette. It is often used for the removal of small or small amounts of liquid in the laboratory. The specifications are different. Different sizes of pipettes are used with different sizes of tips. The shapes produced by different manufacturers are also slightly different. However, the working principle and operation method are basically the same. Pipettes are precision instruments that must be handled and stored with care to prevent damage and to avoid affecting their range.
The micropipette (pipette) first appeared in 1956 and was invented by Schnitger, a scientist at the German Institute of Physiological Chemistry. Later, in 1958, the German company began producing button-type micropipettes, making it the world’s first production. Micro-pipette company. These micropipettes range from 1 to 1000 μl and are suitable for use in clinical routine chemical laboratories. The development of micro-pipette is not only more accurate, but also a variety of varieties, such as micro-dispensers, multi-channel micro-pipettes, etc., the physics of the sample is the following two:
1 using air cushion (also known as piston stroke) loading;
2 Use a piston without air cushion to positively displace the sample. The above two different principles of the micropipette have different specific application ranges.
2. Air pad loader
The piston stroke (air cushion) applicator is conveniently used for the loading of fixed or adjustable volume liquids with a loading volume ranging from less than 1 ul to 10 ml. The air cushion in the applicator separates the liquid sample sucked into the plastic tip from the piston in the applicator, and the air pad moves through the spring-like motion of the applicator piston, thereby driving the tip The liquid in the volume, the increase in the volume and the height of the pipetting tip determines the degree of expansion of the air cushion in the application. Therefore, the volume of piston movement must be about 2% to 4% of the volume that is desired to be drawn. The effects of temperature, air pressure and air humidity must be reduced by structural improvements to the air pad applicator, so that under normal conditions Does not affect the accuracy of the sample. The disposable tip is an important part of the sample loading system. Its shape, material properties and the degree of fit with the pipette have a great influence on the accuracy of the sample.
3. Multi-channel pipette
The principle of the multichannel applicator is the same as above. Multichannel injectors are typically 8-channel or 12-channel, consistent with 8X12=96-well microplates. The use of a multi-channel applicator not only reduces the number of loading operations by the experimental operator, but also improves the precision of the loading.
4. Electronics and distributors
The principle of the electronic applicator and the dispenser is the same as described above. The electronic pipette and dispenser are semi-automatic sample loading systems. The biggest advantage of the electronic pipette is its high sample repeatability and wide application range.