Cell picking device

1 . A cell picking device for sucking cells from a liquid sample in a sample container using a pipette tip, comprising:

a suction arm configured to receive the pipette tip, such that the pipette tip is attached to the suction arm;

a first driver configured to drive the suction arm and cause the suction arm to perform a sucking operation; and

a controller that controls an operation of the first driver, wherein the controller is configured to:

cause the first driver to advance the suction arm in an axial direction of the pipette tip and to tilt the pipette tip such that an end of the pipette tip comes into contact with a bottom surface of the sample container and to tilt the suction arm relative to a vertical direction such that the pipette tip attached to the suction arm is bent at a first tilt angle by the bottom surface of the sample container,

cause the first driver to move the suction arm such that the end of the pipette tip scans the bottom surface of the sample container in a horizontal direction toward a predetermined position,

cause the first driver to further tilt the suction arm by a predetermined angle by rotating the pipette tip such that the pipette tip is bent at a second tilt angle that is more horizontal than the first tilt angle, and

cause the suction arm to perform a sucking operation such that a sample is sucked through the end of the pipette tip by:

causing the suction arm to advance towards and press the end of the pipette tip against the bottom surface of the sample container, such that an elastic material of the pipette tip is bent due to the pressing of the end of the pipette tip against the bottom surface of the sample container, and

while the end of the pipette tip is bent and is in contact with the bottom surface of the sample container, cause the suction arm to move such that the pipette tip:

scans the bottom surface of the sample container in a horizontal direction; and

separates cells adsorbed to the bottom surface of the sample container.

2 . The cell picking device according to claim 1 , wherein

the controller causes the suction arm to start performing a sucking operation in a period between starting and stopping tilt control with respect to the suction arm.

3 . The cell picking device according to claim 1 , wherein the controller is further configured to control the suction arm to undo a tilt of the suction arm after control for a sucking operation is stopped.

4 . The cell picking device according to claim 1 , wherein

the predetermined angle is larger than 0 degree.

5 . The cell picking device according to claim 1 , wherein

the predetermined angle is equal to or smaller than 2 degrees.

6 . The cell picking device according to claim 1 , wherein the controller is further configured to:

cause the first driver to retract the suction arm at a first speed in the axial direction until an end of the pipette tip reaches a predetermined height after control for a sucking operation is stopped, and

cause the first driver to retract the suction arm at a second speed larger than the first speed in the axial direction after an end of the pipette tip reaches the predetermined height.

7 . The cell picking device according to claim 6 , wherein

the second speed is equal to or larger than 10 times of the first speed.

8 . The cell picking device according to claim 6 , wherein

the predetermined height is a height of a liquid surface of a sample in the sample container.

9 . The cell picking device according to claim 1 , further comprising:

a platform configured to receive a culture plate including a plurality of wells, and

a second driver that drives the platform,

wherein the controller is further configured to:

control the first or second driver such that a position of a well included in the plurality of wells accessible by the suction arm changes sequentially in the culture plate, and

cause the suction arm to perform a discharging operation such that a sample is discharged through an end of the pipette tip, and

cause the suction arm to alternatively perform the sucking operation and the discharging operation.

10 . The cell picking device according to claim 9 , further comprising:

a pipette tip rack placed on the platform and configured to hold a plurality of replacement pipette tips,

wherein the first driver is configured to detach the pipette tip from the suction arm, and the controller is further configured to:

control the first driver to detach the pipette tip from the suction arm,

control the first or second driver such that a position of a replacement pipette tip included in the plurality of replacement pipette tips accessible by the suction arm changes sequentially in the pipette tip rack,

control the first or second driver such that any replacement pipette tip included in the plurality of replacement pipette tips in the pipette tip rack is attached to the suction arm as the pipette tip, and

control alternatively alternately a sucking operation, a discharging operation, detachment of the pipette tip, and attachment of the pipette tip.

11 . The cell picking device according to claim 10 , wherein

the second driver includes a rotator that rotates the platform in a horizontal plane,

the controller is configured to cause the rotator to rotate such that the culture plate is located closer to the suction arm than the pipette tip rack when the discharging operation is performed, and

the controller is configured to cause the rotator to rotate such that the pipette tip rack is located closer to the suction arm than the culture plate when attaching the pipette tip.