Tecan Trading Ag

Robert Liebhard

Adi Zuppiger

Torleif Ove Bjornson

Nikolaus Ingenhoven

Werner Hälg

Dirk Heerklotz

Werner HÄLG

A method of selecting pipetting parameters of a pipetting device for dispensing or pipetting a specific volume of a liquid sample, includes a fluid column of a fluid chamber of the pipetting device set into oscillation at the beginning of the aspiration, the pressure is monitored with the pressure transducer in the fluid chamber, and the pressure changes generated during aspiration into measuring signals are recorded. These measuring signals are processed by a computer or micro-processor and reproduced as a pressure curve, which is characteristic for the fluid column with the aspirated liquid sample, and which is compared with known pressure curves. Based on this comparison, pipetting parameters of the pipetting device are selected for the dispense or for pipetting a specific volume of the liquid sample. Selectable pipetting parameters include a speed of a movement of a pump piston of the pipetting device.

Method for selecting pipetting parameters for a liquid

The present invention relates to a method for classifying a liquid () in a known pipetting system for this liquid (), the method being characterized in that the changes of a selected, measurable, and physically founded virtual parameter are detected as a data set typical for this liquid (); this typical data set of the selected virtual parameter is compared to corresponding data sets of known liquids, and the liquid () is classified on the basis of this comparison. An especially preferred method and a device for classifying a liquid () relate to a device which comprises a fluid chamber (), to which a measuring chamber () is connected, whose internal pressure is monitored using a pressure transducer (). At least a first part () of this fluid chamber () may be brought into fluid connection with a sample () of this liquid ().

A pipetting apparatus has a fluidic space to which a pressure transducer with a pressure sensor is attached with a gas filled space. The fluidic space is defined by a pipette tip, a first tubing that connects the pipette tip to a pump, and an active part of the pump. The pipetting apparatus further has an impulse generating mechanism that is in operative contact with a column of system liquid inside the fluidic space. The impulse generating mechanism induces a vertical movement in the system liquid column, which results in a pressure variation in the gas filled space that is pneumatically connected with the fluidic space. This pressure variation, as recorded with the pressure transducer and as processed by a first data processing unit during utilization of this pipetting apparatus, is taken as an indicator for the detection of penetration or of quitting of a surface of a liquid, with an orifice of the pipette tip, of which liquid an amount is to be aspirated and dispensed. This pressure variation is also taken as an indicator for the detection of the presence or the absence of gas bubbles in the system liquid contained in the fluidic space of this pipetting apparatus.

Pipetting apparatus with integrated liquid level and/or gas bubble detection

A pipetting apparatus () comprises a fluidic space (), to which a pressure transducer () with a pressure sensor () is attached with a gas filled space (). The fluidic space () is defined by a pipette tip (), a first tubing () that connects the pipette tip () to a pump (), and an active part () of the pump (). The pipetting apparatus () according to the present invention is characterized in that the pipetting apparatus () further comprises an impulse generating means () that is in operative contact with a column () of system liquid () inside the fluidic space (). The impulse generating means () is designed to induce a vertical movement in this system liquid column (), which results in a pressure variation in the gas filled space () that is pneumatically connected with the fluidic space (). This pressure variation&#x2014;as recorded with the pressure transducer () and as processed by a first data processing unit () during utilization of this pipetting apparatus&#x2014;is taken as an indicator for the detection of penetration or of quitting of a surface () of a liquid, with an orifice () of the pipette tip (), of which liquid an amount is to be aspirated and dispensed. This pressure variation is also taken as an indicator for the detection of the presence or the absence of gas bubbles in the system liquid () contained in the fluidic space () of this pipetting apparatus.

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Zurich, Switzerland

Robert Liebhard