4 Commonly Used Lab Pipette Types

While all laboratory pipettes perform the same functions of aspirating, transporting and dispensing liquids, performance and accuracy can vary significantly between models. Below, we spotlight some of the most common lab pipette types used in modern science. Some are staples in high school laboratories, while others are reserved for cutting-edge research institutions.

Air displacement micropipettes

The most common micropipettes use air displacement to aspirate and dispense liquid. An air cushion in the pipette tip is used to expel air and create a vacuum that draws liquid into the chamber. Advanced laboratory-specific air displacement micropipettes feature air cushion volume settings that can be adjusted to fit the needs of the operator. Once set, the pipette expels the amount of air indicated on the volume setting and replaces it with the same volume of liquid.

While highly accurate, air displacement micro pipetting performance can be affected by factors such as temperature, atmospheric pressure and the viscosity of the liquid.

Positive displacement pipette

Positive displacement pipettes use piston-driven displacement to aspirate and dispense liquid. Unlike their air displacement counterparts, positive displacement pipettes use a piston that comes into direct contact with the liquid. The internal piston is pushed down the chamber, makes contact with the liquid and is then pulled up. This upward pressure creates a vacuum and draws liquid into the tip.

Electronic pipettes

Pipetting often calls for dozens of individual transfers, leaving laboratory personal fatigued and at risk of repetitive strain injury. Electronic pipettes automate the displacement process and allow personnel to aspirate and dispense liquid at the touch of a button. The use of an electronic motor also supports smoother and less disruptive air displacement, which helps to prevent the formation of air bubbles and reduce the risk of barrel contamination.

Multichannel pipettes

Another great way to boost efficiency in the lab, multichannel pipettes are designed to fast-track repetitive tasks. Most models feature between 8 to 12 tips and allow operators to simultaneously extract, transport and dispense multiple samples. As well as increasing productivity in the laboratory, multichannel pipettes can be a good way to minimise hand stress and prevent repetitive strain injury in the workplace.

For best results it’s essential to adhere to best practice pipetting techniques. Genetic research expert Lee Moir spotlights some key hands-on pipetting tips, as well as methods outlined in the MRC Harwell Institute Pipetting Skills course, in ‘The Art of Pipetting - Top Tips’