The pipette, also known as a pipet, pipettor, or chemical dropper, is some kind of instrument in the laboratory. The pipette is especially for measuring the liquid volume and absorbing the liquid to move it to other containers. In general, the pipette is mostly used in biological experiments 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 a 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 the Eppendorf company, inherited the patent right and started the commercial production of micropipettes in the 1960s.
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, and graduation tails before using pipettes.
2. Suction: use the thumb and middle finger of your right hand to pinch the upper end of a pipette, then insert the lower end into the solution to a depth of 10 mm to 20 mm. Use the ear-ball to absorb the solution into the tube. Use your left hand to hold a rubber suction bulb and connect it to the upper end of the pipette. Suck the solution slowly (Notice: In case of not diluting the solution, the sucked solution cannot be reflowed to the original bottle) and use the index finger of your right hand to take the pipette out.
Turn the pipette horizontally in order to make the solution touch above the graduation and replace the inwall water. Discard the solution from the lower end of the pipette and repeat washing three times. Finally, you can imbibe the solution to a level of 5 mm above the graduation and use the index finger of your right hand to press the upper end of the pipette immediately.
3. Adjust the liquid level: lift the pipette upward to leave the liquid level and use filter paper to clean the outer wall water, the end of the pipette still resting on the inner wall of the container. The pipe body remains upright, then a slightly 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 the finger, and 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 flow out. If the pipette is not marked “blow”, no need to blow out the solution remaining at the end o the pipette tip, as the pipette calibration volume does not include this part of the residual solution.
5. Original data record: normally, the relevant original data record of the pipette can be given to two decimal places.