The pipette, also known as pipet, pipettor, or chemical dropper, is some kind of instrument in the laboratory. The pipette is especially for measuring the liquid volume and absorb the liquid to move it to other containers. In general, the pipette is mostly used in the biological experiment or chemical experiments.
Through a large number of designs, different degrees of accuracy and precision are achieved. Currently, the applied types range from the single-channel pipette to the complicated electronic control digital pipette. Moreover, a lot of pipettes can form partial vacuum above the liquid level within the container, and absorb or discharge the liquid by optionally adjusting the vacuum volume. However, the degrees of accuracy of measuring have significant differences according to different types of pipettes.
The world’s first micropipette was invented by the German Dr. Hans Schmitz in 1960. Afterward, Heinrich Netheler, the founder of Eppendorf company, inherited the patent right and started the commercial production of micropipette in the 1960s.
In terms of the adjustable pipette, it was invented by a group of people who come from Wisconsin, the US. Among them, the main inventors include Warren Gilson, and Henry Lardy, professor of biology and chemistry at the University of Wisconsin–Madison.
Steps to use pipette correctly
The step of pre-wetting suction liquid is beneficial for viscous liquid to achieve a good effect, the operation mechanism is as follows: firstly, the pipette should inhale the sample liquid, then discharge, suction headwall will adsorb a layer of liquid, so that the surface adsorption can become saturation quickly, and then inhale the sample liquid, finally discharge the volume of the liquid.
1. Pre-use check: check the pipette mark, accuracy level, scale mark position, etc.
2. Suction: pinch the upper end of the pipette with the right thumb and middle finger, insert the lower mouth of the pipette into the solution to be absorbed, generally 10-20mm. Use the ear-ball to absorb the solution to the tube.
3. Adjust the liquid level: lift the pipette upward to leave the liquid level, the end of the pipette still resting on the inner wall of the container. The pipe body remains upright, then a sightly relaxed finger so that the solution can flow out of the tube from the lower mouth slowly, until the bottom of the meniscus of the solution and the line tangent, then immediately press the tube mouth. Remove the tip of the droplet against the wall, then move the pipette and insert it into the receiver.
4. Release solution: make the pipette upright, the lower end of the pipe should be close to the wall of the receiver bottle. Slightly loosen finger, let the solution flow slowly along with the wall o bottle, after all the solution flows, please wait for 15s to take out the pipette, in order to make the part of the solution attached to the pipe wall to flow out. If the pipette is not marked “blow”, no needs to blow out the solution remaining in the end o the pipette tip, as the pipette calibration volume does not include this part of the residual solution.