Aligning method for leading-out hole and collecting hole of micro-fluidic chip and liquid drop collecting device

Abstract

The invention discloses a method for aligning a leading-out hole and a collecting hole of a micro-fluidic chip and a liquid drop collecting device. The method comprises the following steps: setting an initial micro-fluidic chip, ensuring that a cell leading-out structure on the initial micro-fluidic chip is in a vertical relationship with the initial micro-fluidic chip, taking the cell leading-out structure as a standard measurement coordinate, and simultaneously obtaining a coordinate of a corresponding reference hole; specific coordinates of leading-out holes at the tail end of a cell leading-out structure on the micro-fluidic chip in the actual use condition are compared to obtain a coordinate position relationship corresponding to each collection hole, so that the problem that liquid drops cannot be accurately collected is fundamentally avoided through coordinate algorithm logic; and the collection quantity of samples is greatly increased while the accuracy of the operation process is ensured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of biological cells, and particularly relates to a microfluidic chip export hole and collection hole alignment method and a droplet collection device. BACKGROUND

[0002] The microfluidic chip has been widely applied to the single cell sorting field, and the Chinese utility model patent CN216614602U discloses an automatic collection module for single cell sorting. The device can be installed with a container, and can sequentially receive the droplets wrapped with single cells exported by the microfluidic chip, has high automation, and greatly improves the work efficiency of the single cell sorting process. The microfluidic chip is provided with a droplet export structure. The droplets flow out through the capillary tube and enter the container on the receiver. However, the automatic collection device has certain problems. The distance between the capillary tube and the receiver on the horizontal plane cannot be automatically adjusted. In the batch production of the chip, if the capillary tube is inclined during production and assembly, or the assembly position of the capillary tube deviates, the center of the capillary tube cannot be aligned with the center of the container on the receiver, and the droplets may stick to the side wall of the container or even flow out of the container. SUMMARY

[0003] The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the application will be apparent from the description and drawings.

[0004] The application provides a microfluidic chip export hole and collection hole alignment method and a droplet collection device. The problem that the droplets cannot be accurately collected is avoided from the root by using a coordinate algorithm logic, so as to ensure the accuracy of the operation process.

[0005] The application discloses a microfluidic chip export hole and collection hole alignment method, which comprises the following steps:

[0006] S1, an initial microfluidic chip is placed on a chip moving platform, and a cell export structure on the initial microfluidic chip is vertically arranged with the initial microfluidic chip;

[0007] S2, a field of view of the initial microfluidic chip is obtained through a microscopic objective lens located above the chip moving platform, and the center of the field of view is aligned with any position on the initial microfluidic chip;

[0008] S3, the end export hole of the cell export structure on the initial microfluidic chip is photographed through a camera located below the chip moving platform, so as to obtain an end export hole image of the cell export structure on the initial microfluidic chip and acquire a center point pixel coordinate (Px0, Py0);

[0009] S4, selecting any collection hole in the hole plate on the hole plate moving platform as a reference hole S0, and moving the position of the hole plate moving platform between the chip moving platform and the camera to align the center of the reference hole S0 with the end collection hole of the cell leading-out structure on the initial microfluidic chip, and recording the position coordinates (X0, Y0) of the center of the reference hole S0 at this time;

[0010] S5, placing another microfluidic chip consistent with the initial microfluidic chip on the chip moving platform, and aligning the center of the field of view with the same position as the selected position of the initial microfluidic chip in step S2;

[0011] S6, taking a picture of the end collection hole of the cell leading-out structure on the microfluidic chip in S5 by the camera, obtaining the end collection hole image of the cell leading-out structure, and acquiring the center pixel coordinates (Px1, Py1) thereof;

[0012] S7, calculating the position coordinates (X1, Y1) that the reference hole S0 should reach according to the formula: (X1, Y1)-(X0, Y0)=k[(Px1, Py1)-(Px0, Py0)], wherein k is the proportional relationship between the camera image pixels and the displacement of the hole plate moving platform;

[0013] S8, controlling the hole plate moving platform to move the reference hole S0 to the position (X1, Y1), and completing the alignment of the end collection hole of the cell leading-out structure on the microfluidic chip with the center of the reference hole S0; other collection holes in the hole plate can reach the position below the end collection hole of the cell leading-out structure on the microfluidic chip by moving according to the default spacing from the reference hole S0 through program control.

[0014] In some embodiments, the center of the field of view in step S2 is aligned with the node position where the cell leading-out action is performed.

[0015] In some embodiments, the chip moving platform adopts a two-axis horizontal moving mode; and the hole plate moving platform adopts a two-axis horizontal moving mode or a three-axis horizontal and vertical moving mode.

[0016] The application further discloses a droplet collection device for implementing the alignment method.

[0017] The chip moving platform is provided with a chip clamping device and is used for placing a microfluidic chip;

[0018] The hole plate moving platform is provided with a hole plate clamping device and is used for placing a hole plate, and is located below the chip moving platform;

[0019] The microscope objective and the camera are located above the chip moving platform and below the hole plate moving platform, respectively;

[0020] A control system for controlling the displacement of the chip moving platform and the orifice plate moving platform;

[0021] The image processing and calculation module is used to receive images captured by the camera, perform calculations, and then send the calculation results to the control system.

[0022] In some implementations, it also includes:

[0023] An illumination unit is arranged around the camera to provide a light source.

[0024] In some embodiments, the chip moving platform adopts a horizontal two-axis movement method; the well plate moving platform adopts a three-axis movement method; through the vertical movement of the well plate moving platform, the end outlet hole of the cell export structure is brought into the liquid in the well plate collection hole, thereby completing the introduction of droplets.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention uses a well plate as a droplet receiving container, and can automatically adjust the initial position of the well plate through image technology, so that the center of the reference hole S0 of the well plate is aligned with the center of the end outlet hole of the cell outlet structure, thereby enabling the droplets to smoothly enter the collection hole of the well plate, avoiding the problem of droplets sticking to the inner wall of the collection hole or flowing out of the hole due to center deviation. Attached Figure Description

[0026] The accompanying drawings, which are provided to further illustrate the invention and constitute a part of this invention, are illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention.

[0027] Figure 1 This is a three-dimensional structural diagram of the droplet collection device of the present invention.

[0028] Figure descriptions: 1. Chip moving platform; 2. Well plate moving platform; 3. Microfluidic chip; 4. Well plate; 5. Microscope objective; 6. Camera; 7. Cell export structure. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments provided by this invention without inventive effort are within the scope of protection of this invention.

[0030] Obviously, the accompanying drawings described below are merely some examples or embodiments of the present invention. Those skilled in the art can apply the present invention to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this invention, modifications to design, manufacturing, or production based on the technical content disclosed in this invention are merely conventional technical means and should not be construed as insufficient disclosure of the present invention.

[0031] In this invention, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention may be combined with other embodiments without conflict.

[0032] This invention discloses a method for aligning the outlet and collection holes of a microfluidic chip, comprising the following steps:

[0033] S1. Select an initial microfluidic chip and place it on the chip moving platform 1. The cell export structure 7 on the initial microfluidic chip is set perpendicular to the initial microfluidic chip.

[0034] S2. Obtain the field of view of the initial microfluidic chip through the microscope objective 5 located above the chip moving platform 1, and align the center of the field of view with any position on the initial microfluidic chip.

[0035] S3. Take a picture of the end outlet hole of the cell outlet structure 7 on the initial microfluidic chip using the camera 6 located below the chip moving platform 1, so as to obtain an image of the end outlet hole of the cell outlet structure 7 on the initial microfluidic chip and obtain its center point pixel coordinates (Px0, Py0).

[0036] S4. Select any collection hole in the well plate 4 on the well plate moving platform 2 as the reference hole S0, and move the position of the well plate moving platform 2 located between the chip moving platform 1 and the camera 6 so that the center of the reference hole S0 is aligned with the end outlet hole of the cell outlet structure 7 on the initial microfluidic chip, and record the position coordinates (X0, Y0) of the center of the reference hole S0 at this time.

[0037] S5. Place another microfluidic chip 3 identical to the initial microfluidic chip on the chip moving platform 1, and align the center of the field of view with the same position as the initial microfluidic chip selected in step S2.

[0038] S6. Take a picture of the end outlet hole of the cell outlet structure 7 of the microfluidic chip 1 in S5 using camera 6, and obtain the image of the end outlet hole of the cell outlet structure 7, and obtain the pixel coordinates (Px1, Py1) of its center point.

[0039] S7. According to the formula: (X1,Y1)-(X0,Y0)=k[(Px1,Py1)-(Px0,Py0)], calculate the position coordinates (X1,Y1) that the reference hole S0 should reach; where k is the ratio of the camera image pixels to the displacement of the hole plate moving platform.

[0040] S8. Control the well plate moving platform 2 to move the reference hole S0 to the (X1,Y1) position to complete the alignment of the end outlet hole of the cell export structure 7 on the microfluidic chip 1 with the center of the reference hole S0; other collection holes in the well plate can be moved by program control to reach below the end outlet hole of the cell export structure 7 on the microfluidic chip according to the default distance from the reference hole S0.

[0041] In this process, the initial microfluidic chip serves as the standard chip, therefore, when installing the cell export structure 7, it is necessary to ensure that it is perpendicular to the chip. For the remaining microfluidic chips, during use, the connection between the cell export structure 7 and the microfluidic chip should be manually ensured to be basically perpendicular; precise positioning is not required. Any microscopic angular tilt deviations can be quickly adjusted using the above logic, thus preventing droplets from falling outside or adhering to the sidewalls of the collection orifice during collection. The cell export structure 7 can be a capillary or other structural form. A straight tubular capillary is preferred.

[0042] In some embodiments, the position on the initial microfluidic chip in step S2 is selected from the location of the opening on the initial microfluidic chip or the inflection point of the channel in the initial microfluidic chip. Specifically, the selected position should be convenient for the operator to operate and remember. Due to the inherent structural characteristics of the microfluidic chip, corresponding opening structures will inevitably be formed. The geometric center of the opening structure can be selected, or due to the bending characteristics of the channel structure itself, the selected position can be chosen at the inflection point, so as to facilitate the operator to perform quick and accurate positioning and reduce possible deviations when selecting the same position.

[0043] In some embodiments, the position of the field of view center aligned with the initial microfluidic chip in step S2 is the node position for performing the cell export action. The reason for setting this position is that in the actual cell optical tweezers sorting process, the microfluidic chip is captured and moved by optical tweezers to drag the sorted target cells to the sorting outlet, and then the target cells are exported by the sheath fluid. If it is not set at the node position for performing the cell export action, the position of the microfluidic chip needs to be moved again during the cell sorting process. This would require the collection hole below to move accordingly for matching, and any movement would introduce mechanical errors due to the mechanical structure, reducing accuracy and affecting the overall effect, while also making the entire coordinated action more complex. Setting it at the node position for performing the cell export action indicates that the target cells have completed the sorting process and moved to the node position where the cell export action needs to be performed. At this point, the position of the microfluidic chip will not be moved again, and therefore the collection hole below does not need to be adjusted accordingly, fundamentally avoiding the mechanical error problems that may occur in the above-mentioned process.

[0044] In some embodiments, the chip moving platform employs a horizontal two-axis movement method; the well plate moving platform employs a horizontal two-axis movement method or a horizontal-vertical three-axis movement method. The chip moving platform itself requires movement along the X and Y axes to ensure normal chip operation. Correspondingly, the well plate moving platform also needs a suitable structural configuration to ensure alignment of the export and collection holes. Furthermore, when droplets fall into the collection hole, such as by inserting a cell export structure into the collection hole, the well plate moving platform needs to be designed as a three-axis moving structure to provide lifting and lowering capabilities.

[0045] The present invention also discloses a droplet collection device for implementing the above-described alignment method, comprising:

[0046] The chip moving platform 1 is equipped with a chip clamping device and is used to place the microfluidic chip 3;

[0047] The perforated plate moving platform 2 is equipped with a perforated plate clamping device for placing the perforated plate 4, and is located below the chip moving platform 1;

[0048] The microscope objective 5 and the camera 6 are located above the chip moving platform 1 and below the orifice plate moving platform 2, respectively.

[0049] A control system is used to control the displacement of the chip moving platform 1 and the orifice plate moving platform 2;

[0050] The image processing and calculation module is used to receive images captured by the camera 6, perform calculations, and then send the calculation results to the control system.

[0051] In some embodiments, it also includes:

[0052] An illumination unit is arranged around the camera to provide a light source.

[0053] In some embodiments, the chip moving platform employs a horizontal, two-axis movement; the well plate moving platform employs a three-axis movement. Through the vertical movement of the well plate moving platform, the distal exit pore of the cell export structure enters the liquid within the collection pore of the well plate, thereby completing the introduction of droplets. If the above method is not used to introduce droplets, the well plate moving platform may not employ a three-axis movement. When selecting the drive structure for the chip moving platform and the well plate moving platform, the chip moving platform can employ a high-precision lead screw adjustment method, while the well plate moving platform can employ a low-precision lead screw adjustment method.

[0054] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for aligning an outlet hole and a collection hole of a microfluidic chip, characterized in that, The method comprises the following steps: S1, selecting an initial microfluidic chip and placing it on a chip moving platform, and the cell guide-out structure on the initial microfluidic chip is vertically arranged with the initial microfluidic chip; S2, acquiring a field of view of the initial microfluidic chip through a microscopic objective lens located above the chip moving platform, and aligning the center of the field of view with any position on the initial microfluidic chip; S3, taking a photo of the end guide-out hole of the cell guide-out structure on the initial microfluidic chip through a camera located below the chip moving platform to obtain an image of the end guide-out hole of the cell guide-out structure on the initial microfluidic chip, and acquiring the center point pixel coordinates (Px0, Py0) thereof; S4, selecting any collection hole in a well plate on a well plate moving platform as a reference hole S0, and moving the position of the well plate moving platform between the chip moving platform and the camera to align the center of the reference hole S0 with the end guide-out hole of the cell guide-out structure on the initial microfluidic chip, and recording the position coordinates (X0, Y0) of the center of the reference hole S0 at this time; S5, placing another microfluidic chip identical to the initial microfluidic chip on the chip moving platform, and aligning the center of the field of view with the same position as the selected position of the initial microfluidic chip in step S2; S6, taking a photo of the end guide-out hole of the cell guide-out structure on the microfluidic chip in S5 through the camera to obtain an image of the end guide-out hole of the cell guide-out structure, and acquiring the center point pixel coordinates (Px1, Py1) thereof; S7, calculating the position coordinates (X1, Y1) that the reference hole S0 should reach according to the formula: (X1, Y1)-(X0, Y0)=k[(Px1, Py1)-(Px0, Py0)], wherein k is the proportional relationship between the camera image pixels and the displacement of the well plate moving platform; S8, controlling the well plate moving platform to move the reference hole S0 to the position (X1, Y1) to complete the alignment of the end guide-out hole of the cell guide-out structure on the microfluidic chip with the center of the reference hole S0; Other collection holes in the well plate can reach the end guide-out hole of the cell guide-out structure on the microfluidic chip by moving according to the default spacing from the reference hole S0 through program control.

2. The method of aligning according to claim 1, wherein, The position of the center of the field of view in step S2 aligning with the initial microfluidic chip is the node position for performing the cell guide-out action.

3. The method of aligning according to claim 1, wherein, The chip moving platform adopts a two-axis horizontal moving mode; the well plate moving platform adopts a two-axis horizontal moving mode or a three-axis horizontal and vertical moving mode.

4. Droplet collection device implementing the alignment method according to any one of claims 1 to 3, characterized in that, It comprises: a chip moving platform provided with a chip clamping device and used for placing a microfluidic chip; a well plate moving platform provided with a well plate clamping device and used for placing a well plate, and located below the chip moving platform; a microscopic objective lens and a camera located above the chip moving platform and below the well plate moving platform, respectively; a control system for controlling the displacement of the chip moving platform and the well plate moving platform; an image processing calculation module for accepting the images taken by the camera, performing calculation, and then sending the calculation results to the control system.

5. The droplet collection device of claim 4, wherein, It further comprises: an illumination unit arranged around the camera to provide a light source.

6. The droplet collection device of claim 4, wherein, The chip moving platform adopts a horizontal moving two-axis moving mode; the hole plate moving platform adopts a three-axis moving mode; through the movement of the hole plate moving platform in the vertical direction, the end outlet hole of the cell outlet structure enters the liquid in the hole plate collection hole, and then the droplet import is completed.

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