Pipetting and Pipette calibration

Published
26 Sep
2014

Your new digital Micropipettes are available as fixed or variable piston-operated pipettors for the accurate and precise sampling and dispensing of liquid volumes. They operate on the air displacement principle and are produced and tested according to EN 1S08655, their conformity and quality are documented through the German H-Sign DIN Standard 12650 under the control of the Thueringian State Office of Verification. The standards used for production and measurements are traceable to the national standards of the Federal Republic of Germany at the Physikalisch-Technische Bundesanstalt (PTB).

Volume setting

The volume of the Micropipette is shown through the handle grip window. On variable pipettes, the delivery volume is set by turning the thumb button clockwise or anticlockwise. Using excessive force to turn the push button outside the range may jam the mechanism and damage the pipette.

Forward pipetting for standard liquids

Depress the operating button to the first stop. Dip the tip just under the liquid surface (2-3 mm) and smoothly release the operating button. Withdraw the tip from the liquid, touching against the edge of the reservoir to remove excess liquid. Dispense the liquid by gently pressing the operating button to the first stop. After a short delay press the button to the second stop. This blow-out will empty the tip completely and ensure accurate pipetting. Release the button to the ready position.

Reverse pipetting for high viscosity or foaming Liquids

Depress the operating button to the second stop. Dip the tip just under the liquid surface (2-3 mm) and smoothly release the operating button. Withdraw the tip from the liquid, touching against the edge of the reservoir to remove excess liquid. Dispense the liquid by gentty pressing the operating button to the first stop. This volume is equal to the set volume. Hold the button in position. The liquid that remains in the tip should not be included in the delivery. The remained liquid should now be discarded with the tip or delivered back into the reservoir.

Pipetting

Use your Micropipette only when a tip is attached. Hold the pipettor vertically when aspirating and dip the tip only 2-3 mm into the liquid. Pre-rinse the tip 5 times before aspiration by filling and emptying the tip. Always control the push button movements with the thumb for consistency. Allow liquids, tips and pipettes to equilibrate to the ambient temperature before use.

Checking pipette calibration

Carefully fit tip onto the tip cone. Pre-rinse tip with distilled water by pipetting the selected volume 5 times. Aspirate the liquid. Pipette liquid into a tared container and read the weight in mgs. Repeat at least 10 times and record each result. Use an analytical balance with a readability of 0.01. mgs. Compare the results with the corresponding calibration volume range. Weighting should place at 20-25 °C. Avoid drafts. Distilled water, weighting vessel, pipettor and tips must be at the same temperature. To calculate the volume, divide the weight of the water by its density (at 20°C:0.9982). This method is based on DIN 12650.
Each Nanolytik Micropipette calibration has been factory checked and certified according to EN ISO 8655 and DIN 12650.

Pipette calibration procedure

Place the calibration tool into the holes of the calibration adjustment lock (under the thumb button). Turn the adjustment lock anticlockwise to decrease and clockwise to increase the volume. Repeat checking calibration until the pipetting results are correct.

Pipette In-house maintenance

Hold down the tip ejector. Place the tooth of the opening tool between tip ejector and tip ejector collar to release the locking mechanism. Carefully release the tip ejector and remove the ejector collar. Place the wrench end of the opening tool over the tip cone and turn it anticlockwise. After removing the tip cone, wipe the piston, the 0-ring and the tip cone with ethanol and a lint free cloth. Before replacing the tip cone grease the piston slightly using the silicon grease provided. After reassembling use the pipettor several times to make sure that the grease is spread evenly. Check the pipettor calibration.

Nanolytik Germany - Pipettes