Abstract: A method for aspirating a first liquid medium of two liquid media of different density from a sample container comprises: lowering a pipette of the laboratory automation device into the sample container until a pipette tip of the pipette has passed a lowering distance from the surface of the first liquid medium in the sample container, wherein the lowering distance is chosen, such that the pipette tip passes at least an aspiration volume in the sample container; aspirating liquid from the sample container during the lowering of the pipette by generating an underpressure in the pipette, wherein the first liquid medium is aspirated, and after the interface and the pipette tip pass each other, the second liquid medium of the two liquid media is aspirated; measuring a pressure in the pipette during the lowering of the pipette and detecting a position of the interface, when a slope of the pressure changes; when the lowering distance has been passed and no interface is detected, aspirating the aspiration volume fro