Here are some very common pipetting technique mistakes and how to avoid them. 1. Wrong penetration depth of the suction head. More correct penetration depth can increase the accuracy by 5%. The tip penetration depth should be 1-2 mm for micro-volume pipettes and 3-6 mm for large-volume pipettes, depending on tip size. If the tip goes too deep into the liquid, the air pressure in the tip will increase, causing too much liquid to be sucked in.

2. Incorrect pipetting angle: The entry angle of your pipette tip into the sample should be as close to 90 degrees as possible, and should not deviate more than 20 degrees from the vertical direction. An angle that is too large may cause too much liquid to be sucked into the tip, resulting in inaccurate pipetting. For example, at an angle of 30 degrees from the vertical, up to 0.7% of the liquid can be overabsorbed.

3. Dispensing is not uniform. By ensuring that the remaining droplets are completely dispensed rather than attached to the tip tip, higher accuracy and sample-to-sample reproducibility are achieved. For most applications, it is recommended to dispense with the tip tip along the container wall, as this reduces or eliminates the amount of sample remaining in the tip. This technique can improve accuracy by 1% or more.

4. Incorrect rinsing When dispensing liquid with a pipette, a layer of liquid will be coated on the inner wall of the tip, resulting in the amount of liquid discharged being slightly less than the required amount. Pre-rinse the new tip at least twice with the liquid to be used, and adjust the inside of the tip.

5. The pipetting rhythm is inconsistent. All samples should maintain a consistent pipetting rhythm. Avoid hasty or rapid operations and pace each step of the pipetting process.

Using the five simple tips above alone can make a big difference in your results, but there are a few more things to consider. Minimize risks associated with your pipetting workflow with the Good Pipetting Practices Risk Check, which takes just a few minutes to assess your pipetting risks and get helpful tips for reducing them.