Käänteispipetoinnin

Käänteispipetointi, often translated as reverse pipetting, is a technique used in laboratories to dispense viscous, volatile, or air-aspirating liquids. Unlike traditional forward pipetting where the plunger is pressed to dispense the entire volume, reverse pipetting involves aspirating a volume slightly larger than the desired amount. The excess liquid is then intentionally blown out or left in the tip, ensuring an accurate transfer of the smaller, intended volume. This method is particularly useful for handling substances that tend to cling to the inside of the pipette tip or that foam easily, which can lead to inaccurate dispensing with forward pipetting.

The process typically begins by setting the pipette to the desired volume and aspirating a slightly larger amount. The pipette tip is then touched to the side of the receiving vessel, and the plunger is pressed to dispense the set volume. A small amount of liquid will remain in the tip due to the larger initial aspiration. This remaining liquid is not dispensed. This technique minimizes errors caused by surface tension and the tendency of viscous liquids to adhere to the pipette tip. Reverse pipetting is a valuable tool for improving precision and accuracy when working with challenging liquids in various scientific applications, including molecular biology, chemistry, and pharmaceuticals.