The pipettes used in the daily laboratory operations should be handled with smooth and standardized procedures. Following the correct steps ensures accurate liquid extraction and also prevents contamination, backflow of liquids and operational errors. 

Before use, check the specifications of the pipette tip to ensure it matches the capacity of the pipette. The size must fit properly for a tight seal. Based on the experimental requirements, choose the regular model, the sterile model or the model with a filter element. When using, only touch the outside of the pipette tip and do not touch the tip opening or the tip tip to prevent contamination by impurities. 

When installing the suction head, hold the pipette vertically and align it with the suction head. Slowly press down to make a secure fit, then gently rotate the auxiliary device to ensure there are no gaps at the connection point. Do not forcefully strike or press down to avoid damaging the front structure of the instrument. Just make sure it is securely installed without loosening or leaking. 

Before starting to draw the liquid, or when changing the aspiration tip or the reagent, it is recommended to repeatedly aspirate and dispense the sample several times to ensure that the liquid moistens the inner wall of the aspiration tip, reducing errors caused by material adsorption and maintaining a stable sample each time. When drawing the liquid, press the finger to the first position, slightly insert the tip of the aspiration tip below the liquid surface, slowly release the button, and slowly draw the liquid at a uniform speed. Slowing down the movement can prevent air bubbles from entering. After the liquid drawing is completed, gently rub the container wall to wipe off the excess liquid on the outer wall of the aspiration tip. 

When discharging the liquid, press the suction tip tightly against the inner wall of the receiving container, maintaining a natural inclination angle. Press first to the first gear to discharge most of the liquid, pause briefly, then press to the second gear to completely expel the remaining liquid inside the suction tip. During the liquid discharge process, do not release the hand quickly to avoid negative pressure causing liquid reflux. Also, do not invert the suction tip containing the liquid upside down to prevent the liquid from flowing back into the pipette and corroding the internal parts. 

After the operation of a single sample is completed, the used pipette tip can be directly discarded by pressing the tip removal button of the pipette. Different samples and different reagents must use new pipette tips and cannot be reused. Cross-contamination must be avoided. Usually, the pipette tips should be kept in a closed storage box and placed in a clean and dry environment to prevent the accumulation of dust and debris. The consumables should be kept clean for long-term use in regular experimental continuous operations.