| 摘要 |
An automatic pipetting device comprising only one pipetting needle having a tip end and an open end. The device comprises a metering syringe having an outlet. The device also comprises a mechanism for cleaning the pipetting needle with a cleaning fluid when the pipetting needle is positioned in a cleaning position. The mechanism comprises a plunger pump, a second tube having a first end and a second end, a first valve, a second valve, and a third tube having a first end and a second end, the second end of the tubing immersed in a cleaning fluid. The second end of the first tube is in fluid communication with both the outlet of the metering syringe and the first valve. The first end of the second tube is in fluid communication with the first valve. The second end of the second tube is in fluid communication with both the plunger pump and the second valve. The first end of the third tube is in fluid communication with the second valve. The mechanism for cleaning the pipetting needle is operated to activate the plunger pump and for opening and closing the first valve and the second valve, so as to establish a predetermined pressure of cleaning fluid in the second tube while the first and second valves are closed and subsequently to force the cleaning fluid through the pipetting needle while the first valve is open and the second valve is closed.
|
