Different methods of Pipette Calibration

In laboratories, the pipettes are very useful in measuring & transferring the liquid volume. Any discrepancy in liquid volume certainly affects the results of the experiments. Therefore, the calibration of pipettes is significant and critical. The pipette calibration involves the measurement of liquid volume under certain ambient parameters and finding the correlation between dispensed volume and the selected volume of the system.

A single drop of any fluid in pipette holds utmost significance to carry out medical, chemical, & pharmaceutical laboratories. All the laboratory equipment including the micropipette; needs to be properly calibrated to measure even the smallest change in the droplet under the adequate environmental conditions. The calibration limits the errors in volume discrepancies while enhancing the pipette efficiency for measurement and dispensing. It checks whether the equipment is dispensing the specified volumes properly and if not; it needs to be fixed with proper medical lab calibration services.

Core to pharmaceutical laboratory operations, the ISO 17025 certified pipette calibration services are in demand.

Standard methods for pipette calibration-

For calibrating liquid handling instruments, there are following commonly used methods-

1. Gravimetry- Conventionally gravimetry is the most reliable method and widely used in laboratories to measure the accuracy and performance of pipettes and other liquid handling devices. This method involves a specialized balance (measurement up to 5-6 decimals) for weighing the volume of liquids. The balance gives a weight which then converted into mass followed by volume conversion using standard formulas and methods.
2. Fluorometry- The fluorometry method is based on the measurement of the different wavelengths emitted by the liquid molecules when an ultraviolet light beam is shone on the sample liquid. Comparing the excitation wavelength and emission wavelengths based on relative fluorescence levels, the precision result is drawn. Fluorescent dyes are very photoactive and generate a strong signal at very low volumes; hence this method is highly effective for nullifying smaller discrepancies in liquid volume.
3. Single-dye photometry- The photometry method for pipette calibration is more precise and accurate than fluorometry & gravimetry methods as it is less sensitive to environmental conditions. In photometry calibration method, a light beam is passed through the cuvette containing dye solution. Then, a photometer is used to measure how much quantity of light passes through it. Using the principle of proportionality that the amount of light absorbed is proportional to the amount of dye, the liquid volumes are determined. It is then followed by uncertainty analysis for error calculations.
4. Ratiometric photometry- More precise than single-dye photometry method, the ratiometric method involves two standardized dyes for volume measurements. This helps in determining and analyzing the absorbance ratios more accurately than individual absorbances of liquids as in single-dye photometric method. The ratiometric method is more reliable, accurate and faster to measure the liquid volumes. This method is highly precise with greater stability

Depending upon the application requirements, one of the above calibration methods is used.

If you are wondering for instrument calibration companies in UAE, Arabcal is the one-stop solution for all your calibration needs. We are ISO 17025 accredited for medical equipment calibration to nullify the uncertainty. The technicians are well-qualified in performing the methods and operating the modern calibration equipment flawlessly ensuring efficiency, accuracy, & safety in the results. The accuracy and precision are important parameters of arabcal services.

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