US 12,455,293 B2
Iterative liquid aspiration
Matthias Dzung, Erlenbach (CH); Patrick Kinney, Hayward, CA (US); Philipp Ott, Steg (CH); Carsten Hase, Zürich (CH); Andreas Schenk, Fürstenbrunn (AT); David Papencordt, Hallein (AT); Philipp Riedel, Zürich (CH); and Thomas Geiges, Männedorf (CH)
Assigned to TECAN TRADING AG, Männedorf (CH)
Filed by TECAN TRADING AG, Männedorf (CH)
Filed on Dec. 17, 2021, as Appl. No. 17/554,221.
Claims priority of application No. 20 216 046 (EP), filed on Dec. 21, 2020.
Prior Publication US 2022/0196696 A1, Jun. 23, 2022
Int. Cl. G01N 35/00 (2006.01); G01N 35/10 (2006.01)
CPC G01N 35/1074 (2013.01) [G01N 35/1011 (2013.01); G01N 35/1016 (2013.01); G01N 2035/1025 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A method for aspirating a first liquid medium of two liquid media of different density from a first sample container, wherein an interface separates the two liquid media, the method performed by a laboratory automation device and comprising:
calculating, by the laboratory automation device, a lowering distance, wherein the lowering distance is lower than a top surface of the first liquid medium in the sample container and the lowering distance is based on an aspiration volume;
lowering a pipette of the laboratory automation device into the first sample container until a pipette tip of the pipette has passed the lowering distance;
aspirating the first liquid medium from the sample container during the lowering of the pipette by generating an underpressure in the pipette by the laboratory automation device, wherein the first liquid medium is aspirated, and after the interface and the pipette tip pass each other, a second liquid medium of the two liquid media is aspirated; and
measuring a pressure in the pipette with a pressure sensor of the laboratory automation device during the lowering of the pipette and detecting a position of the interface using a pressure analysis during the lowering of the pipette;
when the lowering distance has been passed and no interface is detected, stopping the lowering of the pipette by the laboratory automation device, aspirating the aspiration volume from the first liquid medium and dispensing the aspiration volume of the first liquid medium into a second sample container by generating an overpressure in the pipette by the laboratory automation device.