What is the pipette?

Previously, Lebe had written quite a lot of articles related to pipettes . Today, I suddenly felt it. Since I have written so many articles related to pipettes, what is the pipette? Thinking of this Lebe, I went to search for Google and Baidu. I only saw the simple definition of a micropipette on Baidu Encyclopedia. As for what the pipette is, it only summarizes its characteristics. It is a pity. then, Lebes can only try to understand what the pipette is by introducing several aspects of the pipette. If it is to ask Lebe's own opinion, Lebe believes that the pipette is a routine laboratory instrument for the convenience of our users to remove liquid samples. The advantage is easy operation and high accuracy.

1. The pipette is an upgraded version of the pipette

More than a hundred years ago, the elite in the lab began using pipettes to transfer liquids. The so-called pipette is a hollow glass tube with one to N scales on it. Insert the glass tube into the liquid and use the mouth on the other end of the tube (in the beginning, our elite can only use their precious mouth to dry the work) or wash the ear to suck the liquid into the tube, while above The scale tells us how much liquid is inside. After filling the amount we need, plug the end of the aspiration with your thumb, then place the tube in another container and let the liquid in the tube flow into the second container. This way we will be able to transfer the liquid!

However, with the progress of society, the elites found that the pipe was not easy to use, tired and slow, and it was not very clean. So the lazy thoughts accumulated in the brain, accumulated, and then broke out - so the pipette was born! That is to say, pipettes and pipettes have the same effect, the only difference is: First, the accuracy is higher (based on the accuracy of some new pipettes compared to the old pipettes) Sex is also very good); Second, higher efficiency (easy to operate); Third, the structure is more complicated (pipette is a tube, while pipettes are composed of dozens of parts); Fourth, the function is more Powerful (in addition to pipetting, many pipettes have many functions); five, and most importantly, the price is higher! (The price of high technology will definitely be higher.)

2.   How pipettes work

For so-called precision instruments, most of the time you must always introduce its esoteric principles, but the principle of the pipette is very simple - the piston is moved up and down by the telescopic force of the spring to discharge or suck the liquid.

Generally speaking, pipettes are divided into two types, one is air displacement type; the other is external piston type, which is often used as a special pipette, and the application range is narrow. This type of pipette can be used. For the removal of samples with high viscosity.

The so-called air displacement type is to press the piston to press the air inside the lower end of the pipette, and then when the piston moves up, the air pressure inside the lower end of the pipette is smaller than the external air pressure, so that it can be under the action of the external air pressure. I sucked up the liquid. In short, the air goes out and the liquid comes in!

The so-called external piston type is actually the same as the syringe. When you see the working process of the syringe, you can probably understand the principle of the external piston.

Works related to a pipette interested users can access previous article les, les in the "selection and use of pipettes - pipette structures, principles and pipetting mode" has done a specific description.
3.   Pipette range adjustment

The original pipette was unable to adjust the range, which is the fixed-range pipette on the market today. For example, if you buy a 200ul pipette, the volume of liquid transferred each time can only be 200ul . Over time, this type of pipette has been difficult to meet the needs of modern researchers. Although most brands also produce fixed-range pipettes, the relative number of users has been reduced.

Depending on the demand, a pipette with adjustable range was introduced, but at that time there was less range available. Continue with the example: If you buy a 200ul pipette, it has 4 gears, 200ul , 150ul , 100ul , 50ul . That is to say, with this pipette, the volume of liquid that you can transfer can be selected between these four gears, which is much easier than the original fixed-range pipette. However, the range selection of this pipette is also limited, and it is also unable to fully meet the user's requirements. Therefore, we classify this pipette as a fixed-range pipette.

The mainstream pipettes on the market today are adjustable range pipettes that can be freely adjusted within a certain range. In general, the range of a pipette is adjusted from 10 % to 100 % of its maximum range . Or take a 200ul pipette as an example: If you buy a 200ul adjustable range pipette, you can freely transfer liquid in a volume range of 20 - 200ul . This greatly facilitates our users, but it should be noted that for any particular pipette, the smaller the volume of liquid transferred, the lower the general accuracy.

4. Number of channels of the pipette

From the first pipette to the current mainstream of the pipette market, there are pipettes that can only transfer one liquid sample at a time, which we call a single-channel pipette. But with the rapid development of life sciences, many times single-channel pipettes mean inefficiency. For example, if you want to fill a 96- well plate (a 96- well plate is a 96 -well plastic plate that holds a certain volume of liquid), you must repeat 96 moves with a single-channel pipette. Liquid operation, this is not a bad thing, I believe many people who have had this experience will be deeply touched. If you want to fill multiple 96 plates continuously , then one word - tired! As a result, a multi-channel pipette has emerged , which means that multiple liquid samples can be transferred in one pipetting operation. This pipette is commonly called a " shooting gun " . Now, there are many kinds of multi-channel pipettes on the market, such as 6 , 8 , 12 , 16 , 24 , or even 36 , 48 , 64 , and 96 (the supplier calls 96 moves). Liquid workstation). For example, an 8- channel pipette can transfer 8 liquid samples at a time, and so on. Of course, the most used in the market are 8- channel and 12- channel pipettes, so there are not many manufacturers of pipettes that produce 16 or more channels, and there are only one manufacturer.