Patent claim: Method of pipetting a test liquid 10 the method comprisingcontrolling a pipetting system 100 200 300 400 comprising an aspirationdispensing nozzle 30 a pump 40 and a fluid supplier 50 at least part of which are fluidically connectable to each other via a nozzle line 31 a pump line 41 and a fluid supplier line 51 respectively and via at least one valve 60 70 71 72 wherein controlling the pipetting system 100 200 300 400 comprisesmoving the aspirationdispensing nozzle 30 to an aspiration position 1 and aspirating a volume of test liquid 10 while the nozzle line 31 is fluidically connected to the pump line 41 and fluidically disconnected from the fluid supplier line 51moving the aspirationdispensing nozzle 30 to a dispensing position 2 while the nozzle line 31 is fluidically disconnected from the pump line 41fluidically connecting the nozzle line 31 and the pump line 41 in the sample dispensing position 2 and dispensing at least a part of the aspirated test liquid 10.

Related passage: When the liquid discharge to all the dispensing positions of the dispensing target container 42 has been completed or when a different type of discharge liquid 30 is to be discharged the discharge liquid 30 remaining in the nozzle 12 is drained and at the same time the inside and the outside of the nozzle 12 are cleaned.First the discharge valve 11 is brought into the closed state and the head unit 34 described later is moved by the XYZ moving mechanism such that the tip portion of the nozzle 12 is positioned above the draining portion 20 of the cleaning unit 16 in the cleaning and drying unit 14.Then the discharge valve 11 is brought into the open state to drain the discharge liquid 30 remaining in the nozzle 12.At that time the discharge liquid 30 in the nozzle 12 is drained together with thepressure transmission medium 2 by pressing the discharge liquid 30 with the pressure transmission medium 2.This enables the inner surface of the tip portion of the nozzle 12 to be cleaned with the pressure transmission medium 2 that serves also as the cleaning liquid 2.Furthermore a draining step is preferably performed after moving the nozzle 12 by the XYZ moving mechanism to be positioned below an upper end of the wall of the draining portion 20 of the cleaning unit 14 so that the wastes are not scattered to the surroundings.After the draining the discharge valve 11 is brought into the closed state.Next the tip portion of the nozzle 12 is moved by the XYZ moving mechanism to a position above the cleaning portion 18 of the cleaning unit 16 in the cleaning and drying unit 14 and the outer surface of the nozzle 12 is cleaned with the cleaning liquid 2 that is springing out from the cleaning portion 18.When cleaning the nozzle 12 the nozzle 12 is just required to be dipped in the cleaning liquid 2 springing out upward of the springout port 18 instead of inserting the nozzle 12 into the springout port 18.When a cleaning region of the nozzle 12 is to be changed it is just necessary to change the springingout force of the cleaning liquid 2.The cleaning liquid 2 used here is preferably the same as the pressure transmission medium 2.The reason is that if the cleaning liquid 2 and the pressure transmission medium 2 are different from each other mixing of the cleaning liquid 2 and the pressure transmission medium 2 occurs in a region of the tip portion of the nozzle 12 where the tip portion is dipped in the cleaning liquid 2.Subsequently the tip portion of the nozzle 12 is moved by the XYZ moving mechanism to a position above the drying unit 17 in the cleaning and drying unit 14 and the tip portion of the nozzle 12 isinserted into the insertion hole 26.The tip portion of the nozzle 12 is then dried by sucking air around the nozzle 12 and attracting an extra liquid mainly the cleaning liquid 2 that is attached to the outer surface of the nozzle 12.By thus drying the tip portion of the nozzle 12 without leaving the cleaning liquid 2 etc.in a state attached to the outer surface of the tip portion of the nozzle 12 the mixing of the cleaning liquid 2 and the discharge liquid 30 can be reliably avoided when the discharge liquid 30 is sucked in a next cycle.