Patent ID: 8778284

Claim:
A micro plate treating method, comprising a first step of preparing a micro plate having wells arranged in a matrix form, and one or two or more nozzle heads each having nozzles capable of sucking and discharging a fluid and arranged in a matrix form, and moving, relatively to the micro plate, the nozzle heads wherein at least one of the row interval or the column interval of the nozzles is set to a natural number multiple of the row interval or the column interval of the corresponding wells, the natural number being two or more, and at least one of the row number or the column number of the corresponding nozzles is one to the natural number of the row number or the column number of the wells, thereby positioning all the nozzles fitted to each of the nozzle heads in such a manner that all the nozzles are simultaneously inserted into the wells belonging to a first partial well matrix in the micro plate, and a second step of attaining relative movement between the nozzle heads and the micro plate, thereby positioning tips of all the nozzles in such a manner that the tips are simultaneously inserted into the wells belonging to a second partial well matrix, which is the corresponding partial well matrix, in the micro plate, wherein the first or second step comprises the step of applying a magnetic field simultaneously to the inside of the nozzles and the step of removing the magnetic field simultaneously at the time of the suction or discharge, and the magnetic-field-applying step is attained by means of two or more magnets fitted to be moved, along the row direction or the column direction between at least one of gaps between the nozzle rows or the nozzle columns, relatively to the nozzle heads each provided with nozzle rows in which the nozzles are arranged in the direction of the rows and nozzle columns in which the nozzles are arranged in the direction of the columns, whereby the magnets are brought into contact with the nozzles and separated therefrom.