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Pipettes are used frequently in laboratories and results are dependent on their reliable performance. Are you sure your pipette is dispensing the correct amount? While regular pipette checkups can be used to ensure functioning and accurate pipettes, did you know that your handling also has a great influence on pipette performance?
Proper pipetting technique directly affects the success and repeatability of your experiments. Below are a few simple things to remember that will greatly improve your pipetting performance:
Immersing the tip too far can cause more liquid to be aspirated. Conversely, if the tip is not immersed far enough, air can be aspirated. Both result in inaccurate volume. Correct tip immersion depth can improve accuracy by up to 5%, so use the recommended depths shown here. (>2000μl, use 6–10mm depth).
Consistent pipette rhythm and speed
Maintaining consistent pipetting rhythm and speed will produce optimal and more repeatable results. Fast or ‘jerky’ aspiration can cause splashing, aerosols, shaft contamination and loss of sample volume. With consistent rhythm and speed you can achieve up to 5% accuracy improvement.
The ideal temperature for pipetting is at 21.5°C±1°C – the same used for calibration. Avoid drafty or sunlit areas that could cause the large or sudden temperature changes that compromise aspiration accuracy. Pipetting at a constant temperature can improve results by as much as 5%.
Vertical immersion angle
Keep the immersion angle vertical or within 20° of vertical – angles greater than that can produce inaccurate measurements. For micro volume pipettes, keeping the angle close to vertical can improve accuracy by up to 2.5%.