Technical Differences

The air displacement principle - Micropipettes Operate Based on the Air Displacement Principle

The air displacement principle is mainly used for straws and provides precise dispensing with fast and easy operation. By moving the piston on the pipette shaft up and down,
a negative or positive pressure is created. This allows the liquid to be aspirated into or
was kicked out. But the liquid always leaves the inner piston and
The straw shaft is provided with a cushion of air and does not come into contact with the straw.
itself when used correctly This ensures contamination-free yet simple handling
highest precision. But this is also where the application limits of the system lie.
Media that strongly affects the airbag can affect the accuracy of the result. For
for example, fluids with high viscosity or highly volatile media make precision work difficult.

The positive displacement principle - Positive displacement principle

The positive displacement principle is generally used for repetitive or specialized pipettes.
positive displacement pipettes. Unlike air displacement systems, the piston
The positive displacement pipette is in direct contact with the liquid to be pipetted.
The piston aspirates the liquid with a vacuum and wipes the walls of the tip.
during distribution – to the last drop clearly separated from the tip. This principle
It provides highly reproducible results regardless of the fluid and the action of a substance.
airbag. Piston integrated into the device in air displacement models,
located on the end cylinder on positive displacement models and is always
replaced to ensure contamination-free operation. Depending on the model,
this can result in more time to replace the tip and higher consumable costs.