Micropipette is an indispensable precision instrument in the laboratory. Its accuracy and reliability are directly related to the accuracy of experimental data and the reliability of scientific research results. In order to ensure that the micropipette can maintain high precision and stability during use, this calibration procedure is specially formulated. This procedure aims to standardize the calibration process of micropipettes, clarify calibration requirements, improve the accuracy and reliability of calibration results, and provide laboratories with accurate and reliable pipette calibration services.
1. Laboratory environment requirements 1. The laboratory should be kept clean and tidy to avoid airflow, vibration, electromagnetic interference and other factors from affecting the accuracy of calibration results. 2. The laboratory temperature should be controlled between 20°C and 25°C, and the relative humidity should be above 45%. At the same time, the room temperature change is not more than 1℃/h. In addition, the temperature difference between the water temperature and room temperature shall not exceed ±2°C.
2. Calibration tools and equipment 1. Prepare the standards, tools and equipment required for calibration, such as pipettes, pipette tips, balances (grading value is 0.01mg or 0.1mg, selected according to the volume of the pipette), and measuring cylinders , burette, etc. The balance should be placed on a table that is free from dust and vibration, and equipped with an anti-evaporator to prevent the evaporation of the distilled water medium from affecting the calibration results. To ensure the humidity inside the balance (relative humidity 60~90%), a small beaker containing 10mL of distilled water can be placed inside the balance. 2. Before use, ensure that all equipment and tools are in good condition and have been properly maintained and calibrated.
3. Pipette inspection 1. Appearance inspection: Use visual inspection, touch or use a magnifying glass to observe the pipette to ensure that its appearance is intact, without damage or rust. The surface of the plastic parts of the shell should be flat and smooth, and there should be no obvious shrinkage marks, waste edges, cracks, bubbles, deformation, etc. The metal surface coating should be free of peeling, rust and layering. 2. Range check: Check whether the range of the pipette meets the requirements to meet the volume accuracy requirements required for the experiment. 3. Component inspection: Check whether all parts of the pipette are tight and not loose. The button should move up and down flexibly, with clear division boundaries, and should not get stuck when used correctly. The volume adjustment indication part of the adjustable pipette must rotate flexibly within the adjustment range, and the digital indication must be clear and complete.
4. Calibration steps 1. Soaking: Insert the pipette into the standard that needs to be calibrated (such as distilled water) and soak it fully. Make sure the tip and pipette are tightly connected and there is no air leakage. 2. Installation of the suction tip: Install the suction tip on the pipette, ensuring that the installation is firm and not loose. Check whether the suction head is smooth and not blocked. 3. Select the detection point: For quantitative pipettes, select the quantitative volume; for adjustable pipettes, select the maximum value of the nominal capacity, half of the maximum nominal capacity, and the minimum value of the nominal capacity as the detection point. . 4. Prepare the weighing cup: Place the weighing cup into the electronic balance. After the balance display is stable, press the joystick to reset the electronic balance to zero. 5. Capacity adjustment and aspiration: Adjust the capacity of the pipette to the inspection point. Hold the pipette vertically and press the button to the calibration position. At this time, insert the suction nozzle into the container filled with distilled water and keep it 2mm3mm below the liquid surface. Slowly release the button, wait 1s2s and then leave the liquid surface, and Stop on the wall of the container and wipe away the liquid outside the suction nozzle (do not touch the liquid outlet at this time to avoid taking away the liquid in the suction nozzle). 6. Weighing: Place the pipette into the weighing beaker at a certain angle, slowly and uniformly press the pipette to the first gear, wait for 1 to 3 seconds, and then press to the second gear to make the contents in the tip The liquid is completely drained. Record the weighing value and repeat the weighing multiple times (not less than 6 times) to obtain the average value.
5. Data processing and result analysis 1. According to the weighed pure water mass value, the capacity value is obtained through the formula. The formula may vary depending on the specific situation, but usually involves parameters such as density of pure water, mass of weight, density of air, etc. 2. Calculate the average error, maximum error and minimum error of each volume to evaluate the accuracy and reliability of the calibration results. If the error exceeds the allowable range, the experimental process should be checked and recalibrated. 3. Organize the calibration data and results into reports and archive them. At the same time, electronic files are established for easy retrieval and management.
The calibration procedure of micropipette is a rigorous and detailed process, covering many aspects from laboratory environment preparation to specific calibration steps, to data processing and result analysis. By following this procedure, the accuracy and reliability of the micropipette can be ensured, providing a solid foundation for scientific research experiments. In actual operations, relevant personnel should strictly abide by the requirements of this procedure to ensure that every step of the operation meets the standards and avoid the impact of human factors on the verification results. At the same time, micropipettes should be calibrated and maintained regularly to detect and solve problems promptly and extend the service life of the instrument.
Related reading recommendations
Introduction to Opentrons Flex™ Ring Magnetic Module
OT-2 Liquid Handling Robot Quick Start Guide
What is the principle of pipette suction two against one
The experienced service team and strong production support team provide customers with worry-free order services.
