Patent ID: 7524461

Claim:
Motorized pipette which can be held by hand comprising: a housing head; a grip part; and a pipette shaft with a tip receiving section for receiving a detachable pipette tip or for a complete syringe, wherein the housing head includes: an electrical drive motor; a positioning means which is driven by the drive motor for taking up and dispensing exactly defined, extremely small amounts of liquid; an electronic control for the drive motor, at least one actuating element for actuating the electronic control; at least one programming element for at least one of selling and programming different operating modes of the electronic control, said modes comprising at least a take-up cycle and a dispensing cycle; and an optical display means for display of operating modes and settings, wherein the electronic control is adapted for specifying at least a certain nominal take-up volume, and a certain take-up rate for a sample liquid, and wherein actuation of the actuating element is operative for starting either an automatic take-up cycle or an automatic dispensing cycle of the sample liquid and the electronic control automatically stops the take-up cycle or dispensing cycle, and wherein, in at least one selectable operating mode of the electronic control, the electronic control is operative to continue the take-up cycle for the sample liquid by actuating the actuating element, to automatically take up an additional volume, beyond said nominal take-up volume of the sample liquid which is stipulated by means of the electronic control, wherein the additional volume is between 5% and 30% of the nominal take-up volume, wherein the electronic control is operative for producing a take-up rate for the additional volume that is lower than a smallest adjustable take-up rate of the nominal take-up volume, and wherein the additional volume is displayed on the display means.