Collection: Pipettes & Liquid Handling

A fixed-volume pipette does one volume and cannot be misset, which makes it faster and more reproducible for a repeated step and removes a source of operator error. A variable pipette covers a range and suits method development and any bench doing varied work. Labs running a fixed protocol at volume often gain more from fixed-volume units than from another variable.

If you work in 96-well plates, an 8- or 12-channel pipette is the difference between a plate taking minutes and taking an hour, and it improves consistency across a row because the channels dispense together. For tube-to-tube work it offers nothing.

Common practice is every 6 to 12 months, more often for pipettes in heavy use or handling critical measurements, and immediately after a drop or a service. Accuracy drifts silently — a pipette does not announce that it is delivering 9.2 µL instead of 10, and every result taken with it inherits the error.

Air displacement is the standard and suits aqueous solutions. Positive displacement uses a disposable piston in direct contact with the liquid, which is what viscous, dense or volatile samples need — with those, the air cushion in a standard pipette compresses or the vapour pushes back, and the delivered volume is wrong.