Cell transfer device

Abstract

This cell transfer device is provided with: a camera that captures an image of a cell accommodated in a first container; a head that performs an operation of moving to the position of a target cell in the first container on the basis of the image captured by the camera, causing the chip to suction the target cell, moving to a second container, and then causing the target cell to be discharged to the second container; and an information processing unit that corrects the position coordinates at which the head is actually present. The information processing unit: operates the head so that, with a predetermined location in a calibration area in the first container being a target coordinate position to which the head is to move, the chip gives a predetermined trace to the calibration area; causes the camera to capture an image of an area including the trace to identify an actual coordinate position of the trace; and determines a difference between the target coordinate position and the actual coordinate position to obtain a correction value for the position coordinates of the head.

Description

cell transfer device

[0001] The present invention relates to a cell migration device that migrates specific target cells from among cells contained in a first container to a second container.

[0002] For example, in the fields of medical and biological research, there is a need to move cells, such as single cells or cell colonies, from a culture vessel in which the cells are cultured to a work vessel where the cells are examined, observed, etc. For this purpose, a cell moving device is known that uses a head equipped with a suction tip to pick and hold target cells from the culture vessel and then release the held cells into the work vessel.

[0003] When picking cells, it is necessary to accurately position the target cell relative to the tip opening of the suction tip. For example, if the tip opening accesses a position different from the XY coordinate position of the target cell or does not reach the cell culture surface, the target cell cannot be picked. Furthermore, if the tip opening is pressed excessively against the cell culture surface, the tip will be damaged. Patent Document 1 discloses a method for positioning the target cell relative to the tip opening of the suction tip by controlling the gap between the suction tip and its projected image to zero.

[0004] However, the technique of Patent Document 1 requires a separate illumination system to create a projection image of the suction tip, which increases the complexity and cost of the device. Furthermore, simply positioning the suction tip and its projection image does not allow for accurate positioning of the tip opening relative to the target cell at the micron level.

[0005] Patent No. 6173331

[0006] An object of the present invention is to provide a cell migration device that can accurately pick target cells.

[0007] A cell movement device according to one aspect of the present invention is a cell movement device for moving a specific target cell from among cells contained in a first container to a second container, the cell movement device comprising: a camera for capturing images of the cells contained in the first container; a head equipped with a tip having a tip for aspirating and discharging cells, the head moving to the position of the target cell in the first container based on the image captured by the camera, aspirating the target cell into the tip, and then moving to the second container and discharging the target cell from the tip into the second container; and an information processing unit for correcting the actual position coordinates of the head. The information processing unit sets a calibration area within the first container, sets a predetermined location in the calibration area as a target coordinate position to which the head will move, operates the head so that the tip leaves a predetermined trace relative to the calibration area, captures an image of an area including the trace with the camera to identify the actual coordinate position of the trace, and obtains a correction value for the position coordinates of the head by calculating the difference between the target coordinate position and the actual coordinate position.

[0008] FIG. 1 is a diagram schematically illustrating an example of the configuration of a cell migration device according to an embodiment of the present invention. FIG. 2(A) is a cross-sectional view of a tip attached to a head, and a diagram showing the movement mechanism and suction mechanism of the tip. FIG. 2(B) is a cross-sectional view of the tip during suction operation. FIG. 2(C) is an enlarged view of the main parts of FIG. 2(B). FIG. 3 is a block diagram illustrating the electrical configuration of the cell migration device. FIGS. 4(A) and 4(B) are diagrams for explaining problems with conventional cell picking. FIG. 5 is a diagram illustrating the process of setting a calibration area in the first embodiment. FIGS. 6(A) and 6(B) are diagrams illustrating the operation of forming a trace by pressing the tip tip against a cell distribution area. FIGS. 7(A) and 7(B) are schematic diagrams illustrating another example of forming a trace in a cell distribution area. FIG. 8 is a diagram illustrating a specific example of horizontal movement of the tip during the operation of forming a trace in a cell distribution area. FIG. 9 is a diagram illustrating another example of setting a calibration area. FIG. 10 is a flowchart illustrating the cell picking process. FIG. 11 is a flowchart illustrating the correction process. FIG. 12 is a flowchart illustrating the correction process. Fig. 13 is a flowchart showing a correction process according to a modified example. Figs. 14(A) to (D) are diagrams for explaining the correction process according to the second embodiment of the present invention. Figs. 15(A) and (B) are diagrams showing a preferred example of the tip end.

[0009] Embodiments of the present invention are described in detail below with reference to the drawings. The cell migration device according to the present invention can pick and move various types of cells derived from living organisms. Examples of cells derived from living organisms include blood cells, cells such as single cells and fertilized eggs, tissue fragments such as histocultures, cell aggregates such as spheroids and organoids, individuals such as zebrafish and nematodes, and 2D or 3D cell colonies. The term "cell" used herein encompasses these various types of cells. The cell migration device according to the present invention is particularly suitable for picking and moving cells such as single cells, cell aggregates, and cell colonies, which generally require picking under a microscope.

[0010] [Overall Configuration of Cell Migration Apparatus] Figure 1 is a diagram showing a schematic diagram of the overall configuration of a cell migration apparatus S according to an embodiment of the present invention. Here, a cell migration apparatus S is shown that moves cells C between two containers, i.e., between a culture plate 2 (first container) and a destination plate 4 (second container). Of course, the cell migration apparatus S may also be configured to move cells C between three or more containers.

[0011] The cell movement device S includes a light-transmitting base 1 having a horizontal mounting surface, a camera unit 5 disposed below the base 1, and a head unit 6 disposed above the base 1. A culture plate 2, which is the source of the cells C, is mounted at a first mounting position P1 on the base 1, and a destination plate 4, which is the destination of the cells C, is mounted at a second mounting position P2. The head unit 6 has multiple heads 61 that can move up and down in the Z direction (up and down). A chip 10 that aspirates and discharges the cells C is attached to the bottom end of each head 61. The camera unit 5 and head unit 6 are movable in the X direction (horizontal direction) and the direction perpendicular to the plane of FIG. 1 (Y direction). The culture plate 2 and destination plate 4 are mounted on the top surface of the base 1 within the movable range of the head unit 6.

[0012] Generally speaking, the cell movement device S performs picking by individually aspirating specific target cells C into each of a plurality of chips 10 from a culture plate 2 in which a large number of cells C are cultured. The picked cells C are then moved to a destination plate 4, and the cells C are discharged from the plurality of chips 10 into the destination plate 4 (wells 41). Before picking the cells C, the camera unit 5 captures an image of the cells C held on the culture plate 2, and a sorting operation is performed to select good quality cells C to be moved to the destination plate 4.

[0013] Each part of the cell migration device S will be described below. The base 1 is a flat plate having a predetermined rigidity and formed in part or in whole from a light-transmitting material. A preferred base 1 is a glass plate. By forming the base 1 from a light-transmitting material such as a glass plate, it becomes possible for the camera unit 5, located below the base 1, to capture images of the culture plate 2 and destination plate 4, located on the upper surface of the base 1, through the base 1.

[0014] The culture plate 2 is a container from which the cells C are moved, and includes a plurality of wells 3 for culturing the cells C. Each well 3 is a small container with an open top and a flat bottom 31. The cultured cells C are positioned (adhered or suspended) on the bottom 31. A liquid medium LCM is poured into the wells 3, and test cells are seeded therein. The culture plate 2 is made of a member made of a light-transmitting resin material or glass, so that the cells C can be imaged by a camera unit 5 disposed below. The culture plate 2 may be, for example, a commercially available 6-well plate (e.g., Corning Model No. 3516).

[0015] The destination plate 4 has a plurality of wells 41 into which the cells C picked from the culture plate 2 are discharged. The wells 41 are holes with a bottom that open to the upper surface of the destination plate 4. Each well 41 contains the required number of cells C (usually one) together with a liquid culture medium. The cells C contained in the well 41 are subjected to various tests such as the addition of reagents or reactants, as well as observation and culture. The destination plate 4 is also made of a member made of a light-transmitting resin material or glass. For example, a commercially available 96-well plate (e.g., Corning Model No. 3595) can be used as the destination plate 4.

[0016] The camera unit 5 is a device that captures images of the cells C held on the culture plate 2 or the destination plate 4 from the underside thereof, and includes a lens unit 51 and a camera body 52. ​​The lens unit 51 is an objective lens used in optical microscopes, and includes a group of lenses that form an optical image at a predetermined magnification and a lens barrel that houses this group of lenses. The camera body 52 includes an imaging element such as a CCD image sensor. The lens unit 51 forms an optical image of the object to be imaged on the light-receiving surface of the imaging element. The camera unit 5 is movable in the X and Y directions below the base 1 along guide rails 5G that extend in the left-right direction parallel to the base 1. The lens unit 51 is also movable in the Z direction for focusing.

[0017] The head unit 6 is a device provided for picking cells C from the culture plate 2 and moving them to the destination plate 4. The head unit 6 includes a plurality of heads 61 and a head body 62 to which these heads 61 are attached. A tip 10 for aspirating and discharging cells C is attached to the tip of each head 61. The head body 62 holds the head 61 so that it can move up and down in the +Z and -Z directions (up and down directions), and is movable in the +X and -X directions (horizontal directions) along guide rails 6G. The head body 62 is also movable in the Y direction. In other words, the head 61 is movable in three dimensions of X, Y, and Z.

[0018] The operation of the head 61 is roughly as follows: The head 61, to which the chip 10 is attached, is moved in the XY direction to a coordinate position corresponding to the position of the target cell C in the well 3 (first container) to be moved, which is identified based on an image captured by the camera unit 5. The head 61 is then lowered to approach the target cell C. After the target cell C is sucked into the chip 10, the head 61 is raised and then moved in the XY direction to the destination plate 4 (second container). The target cell C in the chip 10 is discharged into a specified well 41.

[0019] [Details of the Chip and Head] Figure 2(A) is a cross-sectional view of the chip 10 attached to the head 61, and a diagram showing the movement mechanism and suction mechanism of the chip 10. The chip 10 is a tool that sucks or discharges cells C in order to move the cells C, and is equipped with a tip portion 10T having a tip opening t through which the cells C can enter and exit. The chip 10 of this embodiment is composed of an assembly of a syringe 11 and a plunger 12. The syringe 11 has a tubular passage 11P therein, which serves as a suction path for the cells C. The plunger 12 moves back and forth within the tubular passage 11P while making sliding contact with the inner circumferential wall of the syringe 11 that defines the tubular passage 11P.

[0020] The syringe 11 includes a syringe base end 111 formed of a large-diameter cylindrical body and a syringe main body 112 formed of a long, thin-diameter cylindrical body. A tubular passage 11P is formed in the syringe main body 112. The tip opening t described above is provided in a syringe tip end 113 (tip end) at the lower end of the syringe main body 112. One end of the tubular passage 11P is connected to the tip opening t. The syringe base end 111 is connected to the other end of the syringe main body 112 via a tapered portion. The upper end portion of the syringe base end 111 is fitted into the lower end of the head 61.

[0021] The plunger 12 includes a cylindrical plunger base end 121, a needle-shaped plunger main body 122 continuing below the plunger base end 121, and a plunger tip end 123 which is the lower end of the plunger main body 122. The plunger 12 is assembled to the syringe 11 in such a manner that the plunger base end 121 is housed within the syringe base end 111 and the plunger main body 122 is inserted into the tubular passage 11P of the syringe main body 112. In the state shown in FIG. 2(A) where the plunger main body 122 is inserted deepest into the syringe main body 112, the plunger tip end 123 protrudes from the tip opening t. A rod 61R which is movable up and down within the internal space of the head 61 is attached to the upper end of the plunger base end 121.

[0022] A head driving unit 64 is provided inside the head main body 62. The head driving unit 64 functions as a mechanism for moving the tip 10 attached to the head 61 in the up and down directions, and as a mechanism for aspirating and discharging the cells C into the tip 10 through the tip opening t of the tip 10. The head driving unit 64 includes a head lifting motor 641 and a plunger lifting motor 642.

[0023] The head lift motor 641 is a motor that serves as a drive source for raising and lowering the head 61 relative to the head body 62. When the head 61 is raised and lowered by the driving of the head lift motor 641, the tip 10 attached to the lower end of the head 61 also rises and lowers. In other words, the height position of the tip opening t of the tip portion 10T can be set to a desired position by controlling the operation of the head lift motor 641.

[0024] The plunger lift motor 642 is a motor that serves as a drive source for raising and lowering the rod 61R within the internal space of the head 61. When the rod 61R is raised and lowered, the plunger 12 attached to this rod 61R also rises and lowers. When the plunger 12 rises relative to the syringe 11, a suction force is generated at the tip opening t. On the other hand, when the plunger 12 descends relative to the syringe 11, a discharge force is generated at the tip opening t. In other words, by controlling the operation of the plunger lift motor 642, the suction operation and discharge operation of the cell C by the tip 10 can be controlled.

[0025] Fig. 2(A) shows the state in which the plunger 12 is lowered to the lowest position. This state is the state before cells C are aspirated, or the state in which cells C aspirated into the tip 10 have been discharged. The plunger tip 123 protrudes slightly downward from the syringe tip 113. Fig. 2(B) shows the state in which the plunger 12 is raised by a predetermined height. This state is the state of the tip 10 during the aspirating operation to aspirate cells C. Fig. 2(C) shows an enlarged view of the main parts of Fig. 2(B).

[0026] During the suction operation, the plunger tip 123 sinks into the tubular passage 11P. At this time, a suction force is generated at the tip opening t, and the fluid around the tip opening t is sucked into the suction space H formed in the tubular passage 11P by the plunger tip 123 sinking inward. In other words, the culture medium LCM containing the cells C is held in the suction space H. After this suction operation, when the plunger 12 is moved downward, the fluid held in the suction space H is discharged from the tip opening t. The amount of fluid sucked can be adjusted by the height to which the plunger 12 rises, and the speed at which the fluid is sucked can be adjusted by the rate at which the plunger 12 rises.

[0027] The tip 10 may be made of resin, metal, or glass. However, it is desirable that the tip 10 be made of an elastically deformable material. As will be described in detail later, in this embodiment, the tip 10T of the tip 10 may come into contact with the bottom surface 31 of the well 3 to leave a mark, and further, the tip may be moved while in contact. If the tip 10 is elastically deformable, the risk of breakage during this contact can be reduced.

[0028] [Electrical Configuration of Cell Migration Device] Figure 3 is a block diagram showing the electrical configuration of the cell migration device S. The cell migration device S is equipped with a control unit 7 that controls the movement of the head unit 6 (see Figure 1) and the elevation and lowering of the head 61 (chip 10), i.e., the three-dimensional movement of the head 61. In addition, the control unit 7 controls the suction and discharge operations of the cells C into the chip 10, as well as the movement and image capturing operations of the camera unit 5.

[0029] The cell movement device S also includes a camera axis drive unit 53, a servo motor 54, a head unit axis drive unit 63, and a head drive unit 64. The camera axis drive unit 53 includes a drive motor that moves the camera unit 5 horizontally along the guide rail 5G (FIG. 1). The servo motor 54 rotates forward or backward to move the lens unit 51 vertically at a predetermined resolution via a power transmission mechanism (not shown). This allows the focal position of the lens unit 51 to be adjusted to the cell C contained in the well 3. As indicated by the dotted line in FIG. 3, the base 1 may be moved vertically instead of the lens unit 51. The head unit axis drive unit 63 includes a drive motor that moves the head unit 6 (head main body 62) horizontally in the X or Y direction along the guide rail 6G. The head drive unit 64 is as described above with reference to FIG. 2.

[0030] The control unit 7 is made up of a processor and the like, and by executing a predetermined program, functions to include an axis control unit 71, a head control unit 72, an imaging control unit 73, an image processing unit 74, a memory unit 75, and a main control unit 78. Furthermore, the control unit 7 is provided with an input unit 76 for inputting various information to the control unit 7, and a display unit 77 for displaying various information. The input unit 76 accepts input of various operational information from the operator. The display unit 77 functions as a monitor for displaying images captured by the camera unit 5, etc.

[0031] The axis control unit 71 controls the operation of the head unit axis drive unit 63. By controlling the head unit axis drive unit 63, the axis control unit 71 moves the head unit 6 to a predetermined target position in the horizontal direction. The movement of the head 61 (chip 10) between the culture plate 2 and the destination plate 4, the positioning vertically above the cells C contained in the wells 3, and the positioning vertically above the wells 41 to be discharged are achieved by the axis control unit 71 controlling the head unit axis drive unit 63. The axis control unit 71 also controls the camera axis drive unit 53 to control the operation of moving the camera unit 5 along the guide rail 5G. Furthermore, the axis control unit 71 also controls the operation of the head 61 for leaving a mark on the wells 3 by the chip 10, which will be described later.

[0032] The head control unit 72 raises and lowers the head 61 to be controlled toward a predetermined target position by controlling the head lift motor 641 of the head drive unit 64. The head control unit 72 also controls the plunger lift motor 642 to generate a suction force or a discharge force at the tip opening t of the tip 10 at a predetermined timing.

[0033] The imaging control unit 73 controls the imaging operation of the camera unit 5 of the culture plate 2 or the destination plate 4, such as the exposure amount and shutter timing. Furthermore, for the focusing operation, the imaging control unit 73 provides the servo motor 54 with a control pulse for moving the lens unit 51 in the vertical direction at a predetermined pitch (for example, a pitch of several tens of μm).

[0034] The image processing unit 74 performs image processing such as edge detection and pattern recognition processing involving feature extraction on the image data acquired by the camera body 52. ​​The image processing unit 74 performs processing such as recognizing the presence of the cells C on the bottom surface 31 and traces left by the chip 10 on the image, based on an image of the culture plate 2 in which the cells C are cultured. Similarly, the image processing unit 74 performs processing such as recognizing the number, amount, fluorescence intensity, etc. of the cells C contained in the well 41, based on an image of the well 41 to which the cells C have been transferred.

[0035] The storage unit 75 stores various setting values, data, programs, etc. for the cell migration device S. In addition, the storage unit 75 stores information about the culture plate 2 to be used, such as the plate size, the size of the wells 3, and the range of irregularities on the bottom surface 31. Information about the tip shape of the tip 10, such as the outer diameter, wall thickness, and opening diameter of the tip opening t of the syringe tip 113, is also stored in the storage unit 75. Furthermore, setting information such as the suction amount and suction speed in the suction operation of the cells C, and the Z-direction movement pitch and horizontal movement amount of the head 61 in controlling the leaving of a trace, is also stored in the storage unit 75.

[0036] The main control unit 78 comprehensively controls the operations of the camera unit 5 and the head unit 6. The main control unit 78 controls the camera unit 5 and the head unit 6 via the axis control unit 71, the head control unit 72, and the imaging control unit 73 to capture images of the culture plate 2, pick the cell C selected as the target for movement by aspirating it into the chip 10 attached to the head 61, and move the cell C to the destination plate 4. In addition to this comprehensive control, the main control unit 78 also performs correction control to cause the chip 10 to leave a predetermined trace on a calibration area set on the bottom surface 31 of the well 3 or the like, and to determine a correction value for the amount of movement of the head 61 based on the trace. The calibration area is set to an area in the well 3 (first container) that is accessible by the chip 10 and that does not interfere with the target cell to be moved during the access.

[0037] The main control unit 78 functionally includes an information processing unit 79 for the above-described correction control. The information processing unit 79 executes processing for correcting the actual position coordinates of the head 61. The information processing unit 79 includes an area setting unit 791, a trace creation unit 792, and a correction value calculation unit 793. The area setting unit 791 executes processing for setting a calibration area in which a trace is to be applied as a reference position during the correction control. The trace creation unit 792 sets a predetermined location in the calibration area as a target coordinate position to which the head 61 will move, and operates the head 61 so that the tip 10 applies a predetermined trace to the calibration area. The correction value calculation unit 793 executes processing for acquiring a correction value for the position coordinates of the head 61 by having the camera unit 5 capture an image of the area including the trace, identifying the actual coordinate position of the trace, and calculating the difference between the target coordinate position and the actual coordinate position.

[0038] [Problems in Cell Picking] To accurately aspirate, or pick, target cells with the chip 10, it is essential to accurately align the tip opening t of the chip 10 with respect to the target cell. However, in actual cell picking, even if the head 61 is moved to the target position coordinates, picking of the target cell may fail. Factors that hinder this alignment include misalignment of the tip 10T of the chip 10 when attached to the head 61 and variations in the height of the bottom surface 31 of the well 3, which is the culture surface for the cells C.

[0039] The positional deviation of the tip 10T is caused by factors such as deviation in the mounting position of the chip 10 relative to the head 61, thermal expansion / contraction of the guide rail 6G, which is the axis of movement of the head 61, other mechanical errors, and the width of the depth of focus when the height position of the tip 10T is determined based on a camera image. As shown in FIG. 2A, the chip 10 is fitted into the lower end of the head 61, but fitting errors inevitably occur. Furthermore, the effects of thermal expansion / contraction, mechanical errors, and depth of focus cannot be reduced to zero. In other words, the position of the tip 10T of the chip 10 is displaced in the X, Y, and Z directions.

[0040] FIG. 4(A) is a diagram showing a situation in which a cell picking error occurs due to a positional deviation of the tip 10T. Assume that a target cell Ct to be picked is in contact with the bottom surface 31 of the well 3. When the coordinate position of the target cell Ct is identified based on the image captured by the camera unit 5, the head 61 (chip 10) is moved using that coordinate position as the target coordinate position. However, due to the positional deviation in the XYZ directions, the XY position P1 approached by the tip 10T is a position separated by a distance d from the XY position P2 where the target cell Ct is located. Furthermore, an error in the approach height can also occur in the Z direction. In such a situation, the tip 10 fails to pick the target cell Ct.

[0041] In addition, the bottom surface 31 of the well 3 has non-negligible height variations, i.e., surface irregularities. The thickness of the cells C to be picked is, for example, several μm to several tens of μm. Although the bottom surface 31 is horizontal from a macroscopic perspective, when observed on the order of microns, surface irregularities on the order of several μm to several tens of μm exist. Measurements by the inventors have confirmed that the height of the bottom surface 31 of the wells 3 of a commercially available 6-well plate has a maximum height difference of approximately 100 μm between the six wells. When such height variations in the bottom surface 31 exist, it may not be possible to aspirate the cells C even if the tip 10T of the chip 10 is lowered to a certain height position.

[0042] 4(B), the well 3 has a first bottom surface 31a at a certain height, a second bottom surface 31b that is −ha lower than the first bottom surface 31a, and a third bottom surface 31c that is +hb higher than the first bottom surface 31a. The first bottom surface 31a, the second bottom surface 31b, and the third bottom surface 31c are provided on the bottom surface 31 of one well 3, or on one well 3 and another well 3 of one culture plate 2.

[0043] In this situation, suppose the tip 10T of the tip 10 is lowered to the height of the first bottom surface 31a and the target cell Ct is picked. In this case, cell Ct1 in contact with the first bottom surface 31a can be sucked through the tip opening t. However, cell Ct2 in contact with the second bottom surface 31b cannot be sucked because the approach height of the tip 10T is insufficient by -ha. On the other hand, the tip 10T approaches the third bottom surface 31c excessively deep by +hb. While Figure 4(B) shows a state in which the third bottom surface 31c is pressed by the tip 10T and deformed, in reality the tip 10T is bent or damaged. As a result, the suction of cell Ct3 in contact with the third bottom surface 31c often fails. The movement correction control of the head 61 according to this embodiment aims to resolve the above-mentioned problems.

[0044] [First embodiment of correction control] The correction control of this embodiment roughly consists of the following steps 1 to 3: Step 1: Setting a calibration area in the well 3. Step 2: Applying a predetermined trace to the calibration area with the tip 10. Step 3: Obtaining a correction value for the coordinate position using the trace.

[0045] That is, a target coordinate position is given to the drive unit of the head 61 to operate the head 61, and the tip 10T of the tip 10 actually approaches the calibration area in the well 3, leaving some kind of trace. Then, the actual coordinate position that the tip 10T actually approached is identified from the trace, and the difference between the target coordinate position and the actual coordinate position is calculated. Based on the difference between the two, a correction value for the coordinate position that is the movement target of the head 61 is derived. Each of steps 1 to 3 will be described in detail below.

[0046] FIG. 5 shows an example of the calibration area setting process of step 1, executed by the area setting unit 791 of the information processing unit 79. The bottom surface 31 of the well 3, which serves as the culture surface, is assumed to have a cell distribution area CDA where cells are relatively densely packed, while other areas are relatively sparsely populated with cells. The area setting unit 791 sets a calibration area on the bottom surface 31 to which the tip 10T of the tip 10 will actually approach during correction control. FIG. 5 shows an example in which five circular tip correction positions TA1, TA2, TA3, TA4, and TA5 are set as the calibration area. The tip correction position TA1 is located at the center of the bottom surface 31, and the tip correction positions TA2 to TA5 are located at 90-degree intervals around the periphery of the bottom surface 31. The tip correction positions TA1 to TA5 may be fixedly determined in advance or may be determined depending on the occurrence of the cell distribution area CDA on the bottom surface 31.

[0047] Of the five tip correction positions TA1 to TA5, TA3, TA4, and TA5 have cell distribution areas CDA partially overlapping with each other, each containing the target cells Ct1, Ct2, and Ct3 to be moved. For example, when picking target cell Ct1, the calibration area is the cell distribution area CDA present at tip correction position TA3, where a group of unused cells other than target cell Ct1 exists. When picking target cell Ct2, the calibration area is the cell distribution area CDA overlapping tip correction position TA4, where a group of cells other than target cell Ct2 exists.

[0048] 6A and 6B are diagrams showing the implementation status of the trace imparting process of step 2, which is executed by the trace creating unit 792. The trace creating unit 792 presses the syringe tip 113, which is the tip of the chip 10, against the cell distribution area CDA, and controls the operation of the head 61 via the axis control unit 71 so as to form a void EA as a trace in the cell distribution area CDA.

[0049] FIG. 6(A) shows a state in which the syringe tip 113 faces, but is not in contact with, cells C in the cell distribution area CDA on the bottom surface 31. The upper view of FIG. 6(B) shows a state in which the syringe tip 113 is pressed against the bottom surface 31 in the cell distribution area CDA. The lower view of FIG. 6(B) shows a state in which the pressing causes cells C to escape to the periphery of the syringe tip 113, resulting in the formation of a void EA in the cell distribution area CDA where almost no cells C are present. The void EA formed in the cell distribution area CDA where many cells C gather can be easily confirmed in a camera image. In other words, a trace that is easily confirmed on an image can be formed by the simple action of pressing the tip of the chip 10 against the bottom surface 31.

[0050] The trace creation unit 792 provides the axis control unit 71 with a target coordinate position to which the head 61 should be moved, and moves the head in the XY directions. After the movement, the trace creation unit 792 lowers the head 61 at a high first speed until the syringe tip 113 is positioned at a predetermined facing height. The first speed is the normal descent speed or the maximum speed during operation of the head 61. The predetermined facing height is set taking into account the upper limit of the height dimensional tolerance of the bottom surface 31 and mechanical errors of the head unit 6, etc. After the predetermined facing height is reached, the trace creation unit 792 lowers the head 61 at a second speed that is slower than the first speed. The lowering at the second speed includes a mode in which the head 61 is simply lowered at a low speed, a mode in which the head 61 is lowered stepwise at a predetermined pitch, and the like. In the latter mode, the trace creation unit 792 gradually lowers the head 61, for example, at a pitch of several μm. With each pitch of this descent, the camera unit 5 captures an image of the cell distribution area CDA, allowing the pressing trace of the chip 10 to be confirmed. When the void EA as illustrated in FIG. 6(B) is confirmed, the trace creation unit 792 raises the head 61. The first speed and the second speed may be the same. That is, the second speed may be equal to or less than the first speed. For example, in the above-described aspect in which the head 61 is lowered in stages, the head 61 may be lowered in stages after the predetermined opposing height while maintaining the lowering speed at the same speed as the first speed.

[0051] The predetermined opposing height, which is the point at which the descent mode of the head 61 switches from high-speed descent to low-speed descent (stepwise descent), may be changed depending on whether the height position of the cell C has been accurately acquired. This is to shorten as much as possible the period during which the stepwise descent of the head 61 at a predetermined pitch and the image capture by the camera unit 5 are performed, thereby accelerating the process of leaving a trace. The height position of the cell C, i.e., its Z coordinate, may be determined by capturing an image of the cell distribution area CDA prior to the trace-making process. In this case, the trace creation unit 792 sets the height position obtained by adding the upper limit of the mechanical error of the head unit 6 to the Z coordinate of the cell C as the predetermined opposing height. This allows the tip 10 to be lowered at high speed until just before the syringe tip 113 of the tip 10 presses against the cell C, contributing to improved takt time.

[0052] On the other hand, there are cases where the Z coordinate of cell C is estimated but not accurately grasped. In other words, the Z coordinate of cell C is provisionally acquired, but the accuracy is unknown. In this case, the trace creation unit 792 sets the height position obtained by adding the upper limit of the height dimensional tolerance of the bottom surface 31 and the upper limit of the mechanical error of the head unit 6 to the provisionally acquired Z coordinate of cell C as the predetermined opposing height. For example, if the height dimensional tolerance of the bottom surface 31 is ±100 μm and the mechanical error of the head unit 6 is ±50 μm, the height obtained by adding 150 μm to the provisionally acquired Z coordinate of cell C is set as the predetermined opposing height. This allows images before and after the syringe tip 113 presses against cell C to be reliably acquired during the stepwise lowering process of the head 61.

[0053] 7(A) and (B) are diagrams schematically showing the correction value acquisition process of step 3 executed by the correction value calculation unit 793. The correction value calculation unit 793 calculates a movement correction value for the head 61 from the difference between the target coordinate position and the actual coordinate position of the void EA. The cell distribution area CDA in FIG. 7(A) shows the target coordinate position PA (X, Y) set by the trace creation unit 792. If there is no positional deviation of the tip 10T of the chip 10, the syringe tip 113 will come into contact with the target coordinate position PA.

[0054] 7B shows a void EA that is actually formed in the cell distribution area CDA by providing the target coordinate position PA to the axis control unit 71 and operating the head 61 to press the tip of the tip 10 against it. The void EA has a size corresponding to the outer diameter of the syringe tip 113. Therefore, the correction value calculation unit 793 determines the center position of the void EA based on an image including the void EA, and treats this center position as the actual coordinate position PB. For example, a process can be applied in which the outline of the void EA is determined by edge detection image processing, and the obtained outline is replaced with an approximate circle to determine the center position.

[0055] In the example of FIG. 7B , the actual coordinate position PB (Xa, Ya) is misaligned with respect to the target coordinate position PA (X, Y). The correction value calculation unit 793 calculates the difference between these two coordinates and uses this difference as a correction value for the XY movement of the head 61 in the XY plane. The correction value for the head 61 in the Z direction perpendicular to the XY plane is obtained based on the Z coordinate position where the tip 10 is pressed against the bottom surface 31, detected by the stepwise lowering of the tip 10 performed in step 2. Such a correction value is calculated for each well 3 and for each type of tip 10.

[0056] When identifying the void EA from an image including the void EA, the correction value calculation unit 793 may refer to information regarding the shape of the tip of the chip 10. As illustrated in Figure 6(B), if a cell distribution area CDA where many cells C are densely packed is present on the bottom surface 31 of the well 3, it is relatively easy to identify the void EA on the image. However, if only a cell distribution area CDA with a low cell density is present on the bottom surface 31, it may be difficult to distinguish the sparse cell density area from the void EA on the image.

[0057] As described above, the memory unit 75 stores information about the tip shape of the tip 10, such as the outer diameter, wall thickness, and opening diameter of the tip opening t of the syringe tip 113. The void EA formed by pressing the tip of the tip 10 is a trace that generally follows the shape of the tip of the tip 10. Therefore, by referencing this information, it becomes easier to identify the void EA on an image. For example, the void EA can be detected by using a template corresponding to the tip 10T and performing a matching process on an image including the void EA.

[0058] It is also conceivable that simply pressing the tip of the chip 10 in the Z direction will not result in a clear trace being formed on the bottom surface 31 of the well 3, even if information regarding the tip shape is referenced. Furthermore, a nearly circular void EA will not necessarily be formed, and it may be difficult to detect the actual coordinate position PB based on the center of the circle, as illustrated in FIG. 7B . In this case, the trace creation unit 792 may be caused to perform a trace-imparting process in which the tip of the chip 10 is pressed against the cell distribution area CDA and then the chip 10 is moved horizontally in a predetermined direction. This trace-imparting process allows a longitudinal void to be formed in the cell distribution area CDA in a predetermined direction.

[0059] 8 is a diagram showing an example of forming a longitudinal void EAa in a cell distribution area by horizontally moving the tip 10. The trace creating unit 792 lowers the head 61, for example, at 5 μm intervals, to bring the tip 10T into contact with the cell distribution area CDA. When it is confirmed from the image acquired by the camera unit 5 that the tip 10T (syringe tip 113) has come into contact with the cell distribution area CDA, the trace creating unit 792 moves the head 61, for example, by approximately 50 μm in the X direction. This operation causes the contact trace of the tip 10T to extend in the X direction, forming a longitudinal void EAa in the X direction. Such a void EAa has the advantage of being easier to identify on an image than a void formed by simply pressing the tip of the tip against the cell distribution area CDA.

[0060] After the void EAa is formed, the trace creating unit 792 acquires an image including the void EAa and causes the image processing unit 74 to execute processing to determine the outline of the void EAa. If the area of ​​the void EAa is too small compared to the area of ​​the tip 10T, for example, if it is 50% or less, the trace creating unit 792 lowers the head 61 by one pitch and further moves it in the X direction repeatedly. Similar operations are repeated until the area of ​​the void EAa reaches a predetermined size.

[0061] In this case, the correction value calculation unit 793 treats the position corresponding to the starting end SE of the tip 10 in the longitudinal gap EAa in the movement direction as the actual coordinate position PB. When the tip 10 is moved in a predetermined direction with the tip 10T in contact with the cell distribution area CDA or the bottom surface 31, the tip 10 bends as shown in FIG. 8. When bending occurs, a deviation occurs in the positional relationship between the axial center of the head 61 and the tip 10T of the tip 10. For this reason, if the end of the movement direction of the tip 10 is taken as the actual coordinate position PB, an error will occur. Because bending of the tip 10 is unlikely to occur at the starting end SE, the inclusion of errors in the actual coordinate position PB can be suppressed.

[0062] In the above embodiment, an example was shown in which the cell distribution area CDA where cells C are actually distributed is used as the calibration area and a trace is left thereon, but an area other than the cell distribution area CDA may also be used as the calibration area. Figure 9 is a diagram showing another example of setting the calibration area. Circular coating layers 32 (variable object areas) are provided at four locations near the outer periphery of the bottom surface 31 of the well 3. The coating layer 32 is a layer on which a trace can be left when the tip portion 10T of the chip 10 comes into contact. Examples of the coating layer 32 include an easily peelable ink coating layer and a coating layer of a gel-like material.

[0063] In this case, the area setting unit 791 of the information processing unit 79 designates the coating layer 32 as the calibration area. The trace creating unit 792 presses the tip 10T of the tip 10 against the coating layer 32 to form a trace on the coating layer 32. The correction value calculating unit 793 identifies an actual coordinate position from the imprinted trace and derives a correction value from the difference between the target coordinate position set for imprinting the trace and the actual coordinate position. Note that the material forming the calibration area is not limited to the coating layer 32, and may be any variable material whose state can be changed by contact with the tip 10T of the tip 10. For example, the calibration area may be formed of minute objects such as beads or powder.

[0064] [Cell Picking Control Flow] Figure 10 is a flowchart showing the cell picking process. The main controller 78 receives a selection of target cells Ct to be moved from the culture plate 2 to the destination plate 4 from the user via the input unit 76 (step S1). Upon this selection, an image of the bottom surface 31 of the well 3, which is the cell culture surface, captured by the camera unit 5 is displayed on the display unit 77. The user identifies the target cells Ct while visually checking the display unit 77 and inputs the selection into the input unit 76.

[0065] The information processing unit 79 acquires the address of the well 3 in which the selected target cell Ct is present (step S2). For example, when the above-mentioned 6-well plate is used as the culture plate 2, the well address previously assigned to the well is acquired in order to identify which of the six wells the target cell Ct is present in.

[0066] Next, the information processing unit 79 checks whether or not a correction process has been performed on the chip 10 currently attached to the head 61 for the well 3 at the acquired address (step S3). The correction process is a process for correcting the XYZ movement amount of the head 61 described above, taking into account the positional misalignment of the tip 10T of the chip 10 and the variation in height of the bottom surface 31 of the well 3, etc. If a correction value has already been acquired for the well 3 containing the target cell Ct, that is, if the correction value is stored in the memory unit 75 (YES in step S3), the information processing unit 79 corrects the coordinate position of the target cell Ct identified on the image using the correction value (step S4).

[0067] The coordinate position corrected in step S4 becomes the coordinate position to which the head 61 is to be moved. The axis control unit 71 moves the head unit 6 in the XY directions so that the head 61 moves toward the coordinate position. After the XY movement, the head control unit 72 lowers the head 61 (moves in the Z direction) and generates negative pressure at the tip opening t of the tip 10 to suck in the target cell Ct (step S5). Thereafter, the head unit 6 is moved to the destination plate 4. On the other hand, if a correction value has not yet been acquired (NO in step S3), the information processing unit 79 executes processing to acquire the correction value (step S6).

[0068] 11 and 12 are flowcharts showing the correction process. The information processing unit 79 acquires XYZ information, which is information on the XY position and height position of the well 3 at the address acquired in step S2, from the storage unit 75 (step S11). Next, the area setting unit 791 sets a tip correction position, which is a calibration area where a trace is to be left on the tip 10, on the bottom surface 31 of the well 3 (step S12). The processing of step S12 corresponds to the processing of setting the tip correction positions TA1 to TA5 shown in FIG. 5.

[0069] Next, the main controller 78 controls the camera axis driver 53 to move the camera unit 5 in the XY direction and the imaging controller 73 to perform an imaging operation, thereby acquiring an image of the bottom surface 31 of the well 3 (step S13). The image processor 74 performs predetermined image processing on the acquired image, and a recognition process for the cells C distributed on the bottom surface 31 is performed (step S14). Then, based on the cell recognition result, it is confirmed whether a cell group large enough to leave a trace with the chip 10, such as the cell distribution area CDA illustrated in FIG. 5, has been recognized (step S15). If the cell distribution area CDA has not been recognized (NO in step S15), the main controller 78 causes the display unit 77 to display an error message and a message urging the user to add the cells C to the well 3 (step S16).

[0070] On the other hand, if a cell group is recognized on the bottom surface 31 (YES in step S15), the trace creation unit 792 determines a trace position where a trace is to be left on the tip 10 (step S17). The trace position is set in an area where cells other than the target cell Ct gather at the tip correction position determined in step S12. In the example of Figure 5, for example, the trace position is set in the cell distribution area CDA present at the tip correction position TA3, within an unused cell group surrounding the target cell Ct1.

[0071] Next, the trace creation unit 792 acquires the XY coordinate values ​​of the trace position (step S18). These XY coordinate values ​​correspond to the target coordinate position PA illustrated in FIG. 7 and are the XY coordinates to which the head 61 is moved in the trace-imparting operation. The trace creation unit 792 further acquires the Z coordinate of the XY coordinate position (step S19). When acquiring the Z coordinate, the trace creation unit 792 references the height dimensional tolerance data of the bottom surface 31 and the mechanical error data of the head unit 6 stored in the memory unit 75. Based on the XYZ coordinate data acquired in steps S18 and S19, the head 61 is moved in the XY directions, and after that movement, it is lowered (moved in the Z direction) (step S20).

[0072] Next, the camera unit 5 acquires an image of the bottom surface 31 of the well 3, and performs a recognition process for the cells C distributed on the bottom surface 31 based on the image (step S21). The trace creation unit 792 acquires the cell recognition result of step S21 (step S22) and performs a comparison process with the cell recognition result previously acquired in step S14 (step S23). For example, image subtraction processing can be used as this comparison process.

[0073] If there is a difference between the two cell recognition results, the lowering of the head 61 in step S20 causes the tip 10T of the tip 10 to come into contact with the cell distribution area CDA, leaving a trace. If there is no difference between the two cell recognition results (NO in step S24), this means that a trace has not yet been left, so the head 61 is lowered so that the tip 10 is lowered by one pitch (e.g., 5 μm) (step S25). The process then returns to step S21 and is repeated. In other words, the height of the tip 10T is gradually lowered, and the degree of the trace is confirmed on the image.

[0074] On the other hand, if a difference is found between the two cell recognition results (YES in step S24), the correction value calculation unit 793 identifies the area related to the difference, i.e., the trace caused by the contact of the tip 10, on the image as the void EA shown in Figure 7(B) (step S26). Furthermore, the correction value calculation unit 793 obtains the outline of the void EA and calculates its center position to obtain the coordinates of the position where the tip 10T of the tip 10 actually contacted the cell distribution area CDA (step S27). These coordinates become the actual coordinate position PB shown in Figure 7(B).

[0075] Next, the correction value calculation unit 793 derives XY correction values ​​for moving the head 61 by calculating the difference between the actual coordinate position PB acquired in step S28 and the target coordinate position PA identified in step S18 (step S28). Furthermore, the correction value calculation unit 793 derives a Z correction value based on the Z height of the tip 10T when the contact mark of the tip 10 is confirmed (step S29). These XYZ correction values ​​are stored in the memory unit 75 and are used during the correction in step S4 of FIG. 10.

[0076] FIG. 13 is a flowchart showing a correction process according to a modified example, in which the manner of descent of the head 61 is changed depending on whether the Z coordinate of the cell C has been accurately acquired. The flowchart in FIG. 13 shows a process that replaces step S19 in FIG. 11 to step S26 in FIG. 12. In step S20 of the above embodiment, an example was shown in which the head 61 is simply moved sequentially in the XY direction and the Z direction. In this modified example, after the head 61 has been moved in the XY direction (step S31), the trace creation unit 792 determines whether the Z coordinate of the cell C has been accurately acquired by the imaging performed up to that point (step S32).

[0077] If the Z coordinate of cell C has been accurately acquired (YES in step S32), the trace creation unit 792 sets the predetermined facing height at which the descent of head 61 switches from high-speed descent to gradual descent to a height position obtained by adding the upper limit of the mechanical error of head unit 6 to the Z coordinate of cell C. Then, the trace creation unit 792 controls the head drive unit 64 via the head control unit 72 to move head 61 in the Z direction at high speed (high-speed descent) until the tip 10T of chip 10 reaches the facing height (step S33).

[0078] On the other hand, if the Z coordinate of cell C cannot be accurately acquired (NO in step S32), the trace creation unit 792 sets the facing height to a height position obtained by adding the upper limit of the height dimensional tolerance of the bottom surface 31 and the upper limit of the mechanical error of the head unit 6 to the provisionally acquired Z coordinate of cell C. Then, the trace creation unit 792 quickly lowers the head 61 until the tip 10T of the tip 10 reaches the facing height (step S34).

[0079] Following step S33 or step S34, the trace creating unit 792 sets the Z movement pitch of the head 61 after the facing height (step S35). For example, it sends an instruction signal to the head control unit 72 to gradually lower the head 61 at a pitch of several μm.

[0080] Thereafter, the camera unit 5 captures an image of the cell distribution area CDA with each pitch of the head 61 downward, and a process for confirming the trace of the tip 10 being pressed against the well 3 is performed. The camera unit 5 acquires an image of the well 3, and a process for recognizing the cells C distributed on the bottom surface 31 is performed based on the image (step S36). The trace creation unit 792 acquires the cell recognition result of step S36 (step S37) and performs a comparison process with the cell recognition result previously acquired in step S14 (step S38). If there is no difference between the two cell recognition results (NO in step S39), the head 61 is lowered one pitch (step S40). The process then returns to step S36 and is repeated. On the other hand, if a difference is confirmed between the two cell recognition results (YES in step S39), the process proceeds to step S26 of FIG. 12. By making the determination in step S32, the execution period of the time-consuming loop of steps S36 to S40 can be shortened.

[0081] [Second Embodiment of Correction Control] In the second embodiment, an example is shown in which the calibration region is a gel-like medium, and the actual coordinate position PB is determined from the suction mark of a cell C sucked into the chip 10. FIGS. 14A to 14D are diagrams for explaining the correction process according to the second embodiment of the present invention. In the first embodiment, an example is shown in which a liquid medium LCM is poured into a well 3, and a cell C is picked up and cultured in contact with the bottom surface 31. Cells may also be cultured in a gel-like medium GCM. The present invention can also be applied to the movement of cells in a gel-like medium GCM.

[0082] 14(A) and 14(D), a large number of cells, including a target cell Cpa to be sucked in the correction control and its surrounding cells Cn, are cultured in a gelatinous medium GCM. The target cell Cpa and the surrounding cells Cn are spaced apart in the X and Y directions, and also in the Z direction.

[0083] The region setting unit 791 of the information processing unit 79 sets a certain three-dimensional region in the gelatinous medium GCM as the calibration region. Here, it is assumed that the calibration region includes the target cell Cpa and surrounding cells Cn. The trace creation unit 792 identifies the XYZ coordinates of the target cell Cpa from the camera image and determines these coordinates as the target coordinate position to which the head 61 will move. This target coordinate position is provided to the axis control unit 71 and head control unit 72, and the head 61 is moved to the XY coordinate of the target coordinate position, while the tip 10T of the tip 10 is lowered to the Z coordinate of the target coordinate position. Then, the tip 10 is caused to perform a suction operation.

[0084] FIG. 14(B) is an image of the gelatinous medium GCM in the calibration area after the suction operation. Even though the suction operation was performed aiming at the target cell Cpa, the target cell Cpa remains in the gelatinous medium GCM. On the other hand, the surrounding cell Cn has disappeared, and it can be seen that the surrounding cell Cn has been sucked into the chip 10 instead. When a cell is sucked into the gelatinous medium GCM, a trace appears due to the temporary hollowing out of the area where the cell was located. That is, as shown in FIG. 14(C), a suction mark Cna remains after the surrounding cell Cn is sucked.

[0085] The correction value calculation unit 793 identifies the coordinate position of the suction mark Cna and treats this as the actual coordinate position.The correction value calculation unit 793 then calculates the difference between the target coordinate position, which is the coordinate of the target cell Cpa to be suctioned, and the actual coordinate position, which is the coordinate of the suction mark Cna where suction was actually performed.Based on this difference, XY correction values ​​and Z correction values ​​for moving the head 61 are obtained, as shown in Figure 13(D).

[0086] [Other Embodiments] While the embodiments of the present invention have been described above, the present invention is not limited to these embodiments and various modifications are possible. For example, in the first embodiment, an example was shown in which the target coordinate position to which the head 61 is to move to form a trace is set in the cell distribution area CDA. Alternatively, a single cell (or a single bead) may be set as the target coordinate position, or the center of two or three adjacent cells may be set as the target coordinate position. A correction value for the position coordinate of the head 61 may be derived based on the trace of the displacement of the single cell as a result of the tip 10 coming into contact with the single cell. The position of the cell that the tip 10 ultimately comes into contact with may also be treated as the target coordinate position, and a correction value may be derived.

[0087] Furthermore, for accurate cell picking, it is desirable for the tip 10's distal end 10T to have a smaller outer diameter. Figures 15(A) and 15(B) show desirable tip shapes for the tip 10. The tip 10T1 in Figure 15(A) has a tapered outer periphery that tapers toward the tip. The tip 10T2 in Figure 15(B) has a stepped shape that tapers toward the tip. Using a tip 10 having such tapered distal ends 10T1 and 10T2 enables more accurate cell picking. However, from the perspective of leaving a trace in the calibration region, the tapered tip of the tip 10 also leaves a small trace, making it difficult to distinguish the trace on the image. Therefore, it is desirable to employ a trace-leaving operation involving movement of the tip 10 in the X direction, as illustrated in Figure 8.

[0088] According to the cell migration device S of this embodiment described above, a target coordinate position is provided to the drive unit of the head 61, and the head 61 is operated, actually leaving a trace with the tip 10 in the calibration area of ​​the well 3 of the culture plate 2. The trace is then used to obtain a correction value for the coordinate position to which the head 61 is to be moved. In other words, based on the actual operation record of the head 61, the deviation between the target coordinate position PA and the actual coordinate position PB is determined, and a correction value is derived. Therefore, an accurate correction value can be obtained even if there is variation in the height of the bottom surface 31 of the well 3 or a positional deviation of the tip 10T of the tip 10 attached to the head 61. Therefore, small target cells Ct having a size of several microns to several tens of microns can be accurately picked.

[0089] [Inventions Included in the Above-Described Embodiments] The above-described embodiments include the following inventions.

[0090] A cell movement device according to one aspect of the present invention is a cell movement device that moves a specific target cell from among cells contained in a first container to a second container, and includes: a camera that images the cells contained in the first container; a head that is equipped with a tip having a tip that aspirates and discharges cells, and that moves to the position of the target cell in the first container based on the image captured by the camera, aspirates the target cell into the tip, and then moves to the second container and discharges the target cell from the tip into the second container; and an information processing unit that corrects the actual position coordinates of the head, wherein the information processing unit sets a calibration area within the first container and sets a predetermined location in the calibration area as a target coordinate position to which the head will move, operates the head so that the tip leaves a predetermined trace relative to the calibration area, images the area including the trace with the camera to identify the actual coordinate position of the trace, and obtains a correction value for the position coordinates of the head by calculating the difference between the target coordinate position and the actual coordinate position.

[0091] According to this cell migration device, a target coordinate position is given, the head is operated, and a trace is actually made with the tip in the calibration area of ​​the first container. Then, the trace is used to obtain a correction value for the coordinate position. In other words, based on the actual operation record of the head, the deviation between the target coordinate position and the actual coordinate position is determined, and a correction value is derived. Therefore, an accurate correction value can be obtained even if there is variation in the height of the culture surface of the first container or misalignment of the tip of the tip attached to the head. Therefore, small target cells ranging in size from a few microns to a few tens of microns can be accurately picked.

[0092] In the above-mentioned cell migration device, it is desirable that the information processing unit sets the calibration region to a cell distribution area in the first container where cells other than the target cell gather, and presses the tip of the tip against the cell distribution area to form a gap in the cell distribution area as the trace.

[0093] According to this aspect, a trace is formed by pressing the tip of the tip against a cell distribution area. When the tip of the tip is pressed against an area where cells are distributed to a certain extent, the cells present in the pressed area are forced to escape to the periphery of the pressed area. As a result, the pressed area becomes a void area where there are no cells or where the number of cells is extremely small. Such voids are easily visible in a camera image. In other words, a trace that is easily visible on an image can be formed by the simple action of pressing the tip of the tip.

[0094] In the cell migration device, the information processing unit can determine the center position of the gap based on an image including the gap, and can treat the center position as the actual coordinate position.

[0095] The gap formed by pressing the tip of the chip against the substrate has a certain area. Therefore, it is desirable to identify any position of the gap as the actual coordinate position. According to the above aspect, the actual coordinate position can be identified by a rational and simple method of determining the center position of the gap.

[0096] In the cell migration device, it is preferable that the information processing unit refers to information relating to the shape of the tip end of the tip when identifying the void from the image including the void.

[0097] Since the first container may contain areas of low cell density, it is conceivable that it may be difficult to identify the voids on the image. According to the above aspect, information on the tip shape, such as the tip shape and size, is referenced, making it easier to identify the voids formed by pressing the tip of the tip on the image.

[0098] In the above-mentioned cell migration device, the information processing unit may press the tip of the tip against the cell distribution area and then move the tip in a predetermined direction, thereby forming a longitudinal gap in the cell distribution area in the predetermined direction.

[0099] According to this embodiment, longitudinal voids can be formed in the cell distribution area by pressing the tip of the tip against the cell and then moving the tip. Such voids have the advantage that they are easier to identify on an image than voids formed by simply pressing the tip of the tip against the cell.

[0100] In this case, it is desirable that the information processing unit treats a position corresponding to the starting end of the tip's movement direction in the longitudinal gap as the actual coordinate position.

[0101] When the tip is moved in a predetermined direction, the tip bends, which can cause a misalignment in the positional relationship between the axial center of the head and the tip end. According to the above aspect, the starting point of the tip movement direction is treated as the actual coordinate position, so the influence of the bend can be eliminated.

[0102] In the above-mentioned cell movement device, the lowering of the head presses the tip of the tip against the cell distribution area, and the information processing unit desirably lowers the head at a first speed until the tip of the tip is positioned at a predetermined opposing height, and after the predetermined height, lowers the head at a second speed that is equal to or lower than the first speed.

[0103] To determine whether the tip has left a mark on the cell distribution area, it is necessary to acquire images before and after the tip tip presses against the cells in the cell distribution area. However, it is acceptable to lower the head at high speed to a height where the tip tip does not clearly contact the cells. According to the above aspect, the head is lowered at a first speed to the opposing height, and then at a slower second speed. This makes it possible to shorten the tact time for the process of leaving a mark by pressing the tip.

[0104] In the cell migration device, it is preferable that the information processing unit lowers the head at a predetermined pitch after the predetermined height, and causes the camera to perform an image capturing operation for each pitch of the descent.

[0105] According to this embodiment, it is possible to reliably capture the trace formed by the head tip pressing against the cell distribution area.

[0106] In the above-mentioned cell movement device, the first container has a flat bottom surface, and cells are positioned on top of the bottom surface. When the height position of the cell has been accurately acquired, the information processing unit sets the opposing height to a height obtained by adding the mechanical error of the head to the height position of the cell, and when the height position of the cell has been provisionally acquired but the accuracy is unknown, it is desirable to set the opposing height to a height obtained by adding the height dimensional tolerance of the bottom surface of the first container and the mechanical error of the head to the provisionally acquired height position of the cell.

[0107] According to this embodiment, the manner in which the head 61 descends is changed depending on whether the height position of the cell has been accurately acquired. Therefore, it is possible to shorten the tact time for the process of leaving a trace and reliably acquire images before and after the tip presses against the cell.

[0108] In the above-mentioned cell migration device, the information processing unit may set the calibration area to a variable object area in the first container in which a variable object whose state can be changed by contact with the chip is placed, and may press the tip of the chip against the variable object area to form a trace in the variable object area as the trace.

[0109] According to this aspect, since a trace can be formed by pressing the tip end against the variable object area, it is possible to avoid pressing the tip end against the cells in the first container.

[0110] In the cell migration device, it is preferable that the information processing unit acquires correction values ​​for the position coordinates of the head in the X and Y directions on an XY plane, and further acquires a correction value in the Z direction perpendicular to the XY plane.

[0111] According to this aspect, the movement of the head can be accurately controlled in the XY plane. Furthermore, if the correction value in the Z direction is acquired, the three-dimensional movement of the head in the XYZ directions can be accurately controlled.

[0112] According to the present invention, it is possible to provide a cell migration device that can accurately pick up target cells.

Claims

1. A cell movement device that moves a specific target cell from among cells contained in a first container to a second container, comprising: a camera that images the cells contained in the first container; a head that is equipped with a tip having a tip that aspirates and discharges cells, and that moves to the position of the target cell in the first container based on the image captured by the camera, aspirates the target cell into the tip, and then moves to the second container and discharges the target cell in the tip into the second container; and an information processing unit that corrects the actual position coordinates of the head, wherein the information processing unit sets a calibration area within the first container, and operates the head so that the tip leaves a specified trace on the calibration area, with a specified location in the calibration area as a target coordinate position to which the head will move, and has the camera capture an image of an area including the trace to identify the actual coordinate position of the trace, and obtains a correction value for the position coordinates of the head by calculating the difference between the target coordinate position and the actual coordinate position.

2. A cell migration device as described in claim 1, wherein the information processing unit sets the calibration area to a cell distribution area in the first container where cells other than the target cell gather, and presses the tip of the tip against the cell distribution area as the trace, thereby forming a gap in the cell distribution area.

3. A cell migration device according to claim 2, wherein the information processing unit determines the center position of the gap based on an image including the gap, and treats the center position as the actual coordinate position.

4. A cell migration device according to claim 2, wherein the information processing unit refers to information relating to the tip shape of the tip when identifying the void from an image including the void.

5. A cell migration device as described in claim 2, wherein the information processing unit presses the tip of the tip against the cell distribution area and then moves the tip in a predetermined direction, thereby forming a longitudinal gap in the cell distribution area in the predetermined direction.

6. A cell migration device according to claim 5, wherein the information processing unit treats a position corresponding to the start end of the tip's migration direction in the longitudinal gap as the actual coordinate position.

7. A cell movement device as described in claim 2, wherein the tip of the tip is pressed against the cell distribution area by lowering the head, and the information processing unit lowers the head at a first speed until the tip of the tip is positioned at a predetermined opposing height, and after the predetermined height, lowers the head at a second speed lower than the first speed.

8. A cell movement device as described in claim 7, wherein the information processing unit lowers the head at a predetermined pitch after the predetermined height and causes the camera to perform an imaging operation for each pitch of the descent.

9. A cell migration device as described in claim 7, wherein the first container has a flat bottom surface, a cell is positioned on top of the bottom surface, and the information processing unit, when the height position of the cell has been accurately acquired, sets the opposing height to a height obtained by adding the mechanical error of the head to the height position of the cell, and when the height position of the cell has been provisionally acquired but the accuracy is unknown, sets the opposing height to a height obtained by adding the height dimensional tolerance of the bottom surface of the first container and the mechanical error of the head to the provisionally acquired height position of the cell.

10. A cell migration device as described in claim 1, wherein the information processing unit sets the calibration region to a variable object area in the first container in which a variable object whose state can be changed by contact with the chip is placed, and presses the tip of the chip against the variable object area as the trace, thereby forming a trace in the variable object area.

11. A cell migration device according to any one of claims 1 to 10, wherein the information processing unit acquires correction values ​​in the X and Y directions on an XY plane as correction values ​​for the position coordinates of the head.

12. A cell migration device according to claim 11, wherein the information processing unit further acquires a correction value in a Z direction perpendicular to the XY plane as a correction value for the position coordinates of the head.

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