Air Displacement Pipettes

Air displacement pipetting, also known as blowout pipetting or reverse pipetting, is a technique used in laboratories to dispense liquids with high accuracy and precision. The principle behind air pipetting is that a positive air pressure is used to dispense a liquid from a pipette tip.

To perform air displacement pipetting, a pipette with a disposable tip is used. The tip is attached to the end of the pipette, and the liquid to be dispensed is drawn up into the tip using the pipette's plunger. Once the desired volume of liquid is in the tip, the pipette is held in a vertical position and the plunger is depressed slightly to create a positive air pressure in the pipette.

The positive air pressure forces the liquid out of the tip in a controlled manner, allowing the user to dispense precise volumes of liquid. The tip is then removed from the liquid, and any remaining liquid in the tip is expelled using the same positive air pressure.

Air displacement pipetting is particularly useful when dispensing viscous or foamy liquids that are difficult to dispense using traditional pipetting techniques. It is also useful when working with small volumes of liquid, as it allows for precise and accurate dispensing.

However, it is important to note that air displacement pipetting can create aerosols and droplets, which can pose a safety hazard when working with hazardous materials. Proper safety precautions, including the use of personal protective equipment and proper ventilation, should always be taken when performing air pipetting in the laboratory.