Pipetting technique that protects accuracy
Small handling habits that reduce bubbles, carryover, variation and wasted samples.
Good technique means controlled speed, consistent angle, correct immersion depth, tip pre-wetting when appropriate and a fresh tip at every sample boundary.
Control the mechanics
Attach the tip with a secure seal, hold the pipette near vertical during aspiration, use a smooth plunger motion and avoid touching the vessel wall unless the method calls for touch-off.
For small volumes, tiny differences in angle, speed and immersion depth can become large differences in delivered volume.
Avoid aerosol and bubble habits
Do not forcefully expel material when aerosols matter. Mix slowly when pipette mixing is needed, and avoid drawing air into the tip.
If liquid reaches the filter or pipette shaft, stop using that tip and follow the lab cleaning or decontamination procedure.
Train around the actual tip and pipette pair
Accuracy is not only a pipette issue. The selected tip is part of the volumetric system, so fit, seal, length and package format should be consistent inside an SOP.
For shared benches, standardize the common tip families and keep exceptions visible so users do not substitute a similar-looking SKU.
Checklist.
Use a tip that seals on the pipette without force.
Keep aspiration speed and immersion depth consistent.
Change tips at each sample, reagent or contamination boundary.
Use filtered tips when aerosol carryover is part of the risk assessment.
Keep the validated pipette-tip pair consistent inside the method.