JP2019203810A - Method for capturing droplet, measurement cell, and droplet capturing device - Google Patents

Abstract

To provide a method for trapping droplets floating on the surface of oil with high capture rate, a measurement cell, and a droplet capturing device.SOLUTION: A fluid containing a plurality of droplets and oil is flown from a flow passage 4 between a chamber part 2 and a flat surface by a flat surface (bottom surface) provided below the chamber part to face a droplet guide surface 21 with a plurality of wells into the chamber part, which has an inner wall 22 in contact with the droplet guide surface at a surface which the droplet guide surface and the inner wall have in common, the inner wall being provided in an opposite direction to the direction of the recess side of the wells. After that, the droplets are captured by the wells of the droplet guide surface.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a droplet capture method, a measurement cell, and a droplet capture device.

  At present, a digital PCR method capable of detecting a gene mutation with high sensitivity is attracting attention. In a digital PCR method using droplets, which is a kind of digital PCR method, first, DNA contained in a specimen is isolated in a droplet, and the type of the isolated DNA is visualized by a method such as fluorescent labeling. Thereafter, the type of DNA contained in the droplet flowing in the flow path is discriminated with a flow cytometer, and the number of each is integrated to quantify the number of target DNAs in the sample.

  On the other hand, in Non-Patent Document 1, a droplet is caused to flow through a microchannel having a droplet guide surface having a plurality of wells on the inner wall, and the fluorescence of the droplet group captured on the droplet guide surface is observed from above. Thus, a technique for determining the presence or absence of a fluorescent dye in a droplet is disclosed.

L. Labanieh et al. Micromachines 2015, 6, 1469-1482.

The inventors are examining a digital PCR method using droplets that detect fluorescence from a group of droplets arranged in a plane. The inventors have studied a method of capturing a droplet on a droplet guide surface having a plurality of wells installed on the inner wall in the microchannel as disclosed in Non-Patent Document 1. Drop capture rate (ratio of the number of captured droplets to the number of input droplets) is about 20%, and it is necessary to flow a large number of droplets to capture a sufficient amount of droplets on the droplet guide surface. I understood.
However, in general, the amount of specimen that can be used for biomolecule measurement is small, and it is desirable that the quantity of specimen to be used for testing is small.
The present disclosure has been made in view of such a situation, and provides a droplet trap technology with a high droplet capture rate.

In order to solve the above problems, a droplet capturing method according to the present disclosure includes:
A chamber portion having a droplet guide surface having a plurality of wells on one inner wall surface of the internal space, and an inner wall in contact with a surface common to the droplet guide surface and provided in a direction opposite to the concave side of the well; A flow path formed between the chamber portion and the plane by the plane provided on the lower side of the chamber portion so as to face the droplet guide surface, oil, and a droplet having a specific gravity lighter than that of the oil, Preparing a measurement cell comprising an introduction part for introducing the oil into the flow path, an oil discharge part for discharging the oil to the outside, and a housing part;
Flowing a fluid containing a plurality of droplets and oil in a flow path in a state where the droplet guide surface is in the measurement cell;
Capturing a plurality of droplets in a plurality of wells of a droplet guide surface using buoyancy of the droplets with respect to oil in the chamber portion;
including.
Further features related to the present disclosure will become apparent from the description of the present specification and the accompanying drawings. The aspects of the present disclosure are achieved and realized by elements and combinations of various elements and the following detailed description and appended claims.
It should be understood that the description herein is merely exemplary and is not intended to limit the scope of the claims or the application in any way.

  According to the present disclosure, it is possible to improve the droplet capture rate in the measurement cell.

It is a figure which shows typically the capture method of a droplet. FIG. 1A shows the state of the measurement cell 1 before flowing the fluid containing the droplet 101 and the oil 102, and FIG. 1B shows the state after flowing the fluid containing the droplet 101 and the oil 102 in the measurement cell 1. FIG. 1C shows a state in which the droplet 101 is captured by the droplet guide surface 21 (a surface on which a plurality of wells are formed as will be described later). It is a figure which shows the schematic structural example of the measurement cell 1 by this embodiment. It is a figure which shows the example of schematic structure of the droplet trapping apparatus 200 by this embodiment. It is a figure which shows typically the operation example of the droplet trapping apparatus 200 by this embodiment. It is a figure which shows the structural example of each measurement cell used by the Example and the comparative example. It is a figure which shows the structure of the droplet guide surface of each measurement cell used by the Example and the comparative example. It is a figure which shows typically the measurement system which observed the fluorescence image of the arrangement | sequence droplet in a measurement cell. It is a figure which shows the fluorescence microscope image of the arrangement | sequence droplet in a measurement cell.

  The present embodiment relates to a biomolecule measurement method, in particular, a droplet trapping method, a measurement cell, and a droplet trapping apparatus related to a gene mutation measurement method. In this embodiment, in order to improve the capture rate of a droplet in a well provided in a measurement cell, a measurement cell provided with a chamber portion connected to a flow path, a droplet supplement device including the measurement cell, and Disclosed is the droplet capture method used.

Hereinafter, the present embodiment will be described with reference to the accompanying drawings. In the accompanying drawings, functionally identical elements may be indicated by the same numbers, and redundant description is omitted. The accompanying drawings show specific embodiments and examples in accordance with the principles of the present disclosure, but these are for the purpose of understanding the present disclosure and are not intended to limit the present disclosure in any way. Not used.
This embodiment has been described in sufficient detail for those skilled in the art to implement the present disclosure, but other implementations and forms are possible, without departing from the scope and spirit of the technical idea of the present disclosure. It is necessary to understand that the configuration and structure can be changed and various elements can be replaced. Therefore, the following description should not be interpreted as being limited to this.

<Example of trap method>
First, a droplet trapping method according to an embodiment of the present disclosure will be described.
FIG. 1 is a diagram schematically showing a droplet capturing method. FIG. 1A shows the state of the measurement cell 1 before flowing the fluid containing the droplet 101 and the oil 102, and FIG. 1B shows the state after flowing the fluid containing the droplet 101 and the oil 102 in the measurement cell 1. FIG. 1C shows a state in which the droplet 101 is captured by the droplet guide surface 21 (a surface on which a plurality of wells are formed as will be described later). First, a fluid containing droplets 101 and oil 102 is caused to flow from the introduction unit 3 into the measurement cell 1. There is no particular limitation on the way the fluid flows as long as the fluid enters the measurement cell. For example, a method of injecting using a pump or the like by connecting a tube or the like to the introduction unit 3 or a method of injecting using a micropipette can be used.

It is preferable that the droplet 101 has a lower density than the oil 102 and floats on the surface of the oil 102. The diameter of the droplet 101 can be selected from the range of 20 μm to 100 μm, more preferably from the range of 20 μm to 60 μm, depending on the application. When the diameter of the droplet 101 is smaller than 20 μm, it is difficult to observe the fluorescence of the droplet, which is not preferable. Further, when the diameter of the droplet 101 is larger than 100 μm, the number of droplets 101 included per unit area of the arranged droplet group is reduced, and the number of droplets that can be subjected to fluorescence evaluation at a time is reduced. . By selecting the diameter of the droplet 101 from the range of 20 μm to 60 μm, the droplet 101 can be evaluated in a state where a sufficient number of droplets 101 can be evaluated at one time. In addition, the droplet 101 is composed of molecules that float in the oil 102, for example, and contains an observation target in the droplet and molecules necessary for forming the observation target in the droplet. Can do. Examples of molecules that can be contained in the droplet 101 include biologically relevant molecules, drugs necessary for PCR reactions, fluorescent dyes, salts, and the like. Further, the droplet 101 may be stabilized with a surfactant. Examples of the surfactant include EA surfactant (manufactured by RainDance), Pico-Surf ^™ 1 (manufactured by dolomite), and the like. Further, the oil 102 may be a liquid that floats the droplet 101. Examples of the oil 102 include Fluorinert (manufactured by 3M), Novec (manufactured by 3M), and the like. When a fluid containing the droplet 101 and the oil 102 is caused to flow to the measurement cell 1, the droplet 101 receives buoyancy and is temporarily captured in the chamber portion 2 as shown in FIG. 1B. Further, a part of the droplet 101 that has floated due to buoyancy is captured by the droplet guide surface 21. Therefore, the droplet 101 is prevented from coming out from the oil discharge part 5. Therefore, the droplet trapping method can be greatly improved by the droplet trapping method of the present disclosure.

After flowing a fluid containing the droplet 101 and the oil 102 to the measurement cell 1, an operation for capturing more droplets 101 on the droplet guide surface 21 may be performed. Examples of the operation for capturing more droplets 101 on the droplet guide surface 21 include an operation for vibrating the measurement cell 1 and an operation for flowing the oil 102 from the introduction unit 3. The operation of vibrating the measurement cell 1 may be performed at the same time when a liquid containing the droplet 101 and the oil 102 is allowed to flow through the measurement cell 1.
With the method for capturing droplets 101 described above, the droplets 101 can be captured and arranged in the measurement cell 1 with a high capture rate.

<Configuration example of measurement cell>
FIG. 2 is a diagram illustrating a schematic configuration example of the measurement cell 1 according to the present embodiment. The measurement cell 1 includes, for example, a chamber part 2, an introduction part 3, a flow path 4, an oil discharge part 5, and a housing part 6. The chamber portion 2 is in contact with a droplet guide surface 21 having a plurality of wells 23 on one inner wall surface and a surface 24 common to the droplet guide surface 21, and the direction in which the well 23 is recessed (the concave side of the well 23). And an inner wall 22 provided in the opposite direction (extending in the opposite direction to the direction recessed from the common surface 24).

  The minimum distance between the droplet guide surface 21 and the flow path 4 is preferably 2D (where D is the average diameter of the droplets) or more. If the minimum distance between the droplet guide surface 21 and the channel 4 is smaller than 2D, the droplet 101 flowing into the chamber part 2 through the channel cannot be sufficiently captured, and the capture rate of the droplet 101 is reduced, which is not preferable. Because. In addition, the shortest distance between the well 23 and the inner wall 22 of the droplet guide surface 21 (the minimum value of the distance between the well and the inner wall on the common surface 24) is 5D (where D is the average diameter of the droplets) or less. Is good. The droplet 101 that has bounced off the inner wall 22 flows to the empty well 23 by the flow of the oil 102 and is captured by the well 23. However, if the shortest distance between the well 23 and the inner wall 22 of the droplet guide surface 21 is greater than 5D, the droplet 101 cannot reach the well 23 and the amount of the droplet 101 that is not captured by the well 23 increases. It is because it is not preferable. The well 23 and the inner wall 22 of the droplet guide surface 21 may be adjacent to each other. In addition, in an application that collectively measures an optical image of a group of droplets arranged on the droplet guide surface, it is preferable that the liquid enemy groups are arranged in a plane so that the imaging can be easily focused. It is preferable that the plurality of wells are arranged in a planar shape.

  The void shape when the chamber section 2 is cut along a plane parallel to the droplet guide surface 21 is not particularly limited, and examples thereof include an ellipse (including a circle), a polygon, and a shape having at least a curve (chamber). And at least a part of the side wall of the portion 2 is formed of a curved surface. In particular, when the shape of the void portion when the chamber portion 2 is cut along a plane parallel to the droplet guide surface 21 is an ellipse, the flow of oil is not inhibited by the corner portion, and the flow of the droplet is improved. The rate at which droplets are trapped in the wells increases.

The droplet guide surface 21 captures and arranges the droplets 101 in the plurality of wells 23. The shape of the well 23 is not particularly limited as long as it can capture the droplet 101. Examples of the shape of the well 23 include a columnar shape, an elliptical columnar shape, a polygonal columnar shape (triangular columnar shape, quadrangular columnar shape, pentagonal columnar shape, hexagonal columnar shape, etc.), a tetrahedral shape, and the like. The inner diameter of the well 23 is preferably in the range of 0.5 to 1.2 times the average droplet diameter in order to minimize droplet position drift. Further, the depth of the well 23 is desirably selected from a range of 0.3 to 1.5 times the average diameter of the droplets 101, more preferably 0.5 to 1.0 times. If the depth of the well 23 is smaller than 0.3 times the average diameter of the droplet 101, the droplet 101 is not captured, which is not preferable. On the other hand, if the depth of the well 23 is larger than 1.5 times the average diameter of the droplet 101, the probability that two or more droplets are trapped in the well 23 increases, which is not preferable. By selecting the depth of the well 23 in the range of 0.5 to 1.0 times the average diameter of the droplet 101, the influence of the depression formed by a plurality of adjacent droplets 101 captured (the depression And the droplet 101 is arranged on the droplet guide surface 21 at a high density while minimizing the probability that two or more droplets are trapped in the well 23. It becomes possible. The number of wells 23 included in the chamber unit 2 is determined in the range of 10 ^{1 to} 10 ⁶ according to the balance between the cost requirement and the performance requirement of the application to be applied.

  The flow path 4 is a flow path connecting the chamber section 2 to the introduction section 3 and the oil discharge section 5, and the chamber section 2 is formed by a plane provided on the lower side of the chamber section 2 so as to face the droplet guide surface 21. Between the chamber portion 2 and the introduction portion 3 and between the chamber portion 2 and the oil discharge portion 5. The flow path 4 is not particularly limited as long as it is a flow path that guides a fluid including the droplet 101 and the oil 102 to the chamber portion 2 and guides excess oil to the oil discharge portion 5. However, the size of the cross section of the flow path is preferably larger than the maximum cross sectional area of the droplet 101. The introduction unit 3 is not particularly limited as long as the droplet 101 and the oil 102 can be introduced into the flow path 4, and the oil discharge unit 5 has a structure capable of discharging the oil to the outside of the measurement cell 1. There is no particular limitation.

  The casing 6 desirably maintains the structure of the measurement cell 1 and has heat resistance up to the boiling point (about 100 ° C.) of the solution forming the droplet. When optically observing the droplet, the transmittance of light having a wavelength of 450 to 750 nm of the casing 61 sandwiched between the droplet guide surface 21 and the outer periphery of the measurement cell 1 is 70% or more. It is desirable to be. When the transmittance is less than 70%, it is difficult to measure the fluorescence of the droplet from the outside of the measurement cell 1, which is not preferable. In addition, when the liquid droplet is optically observed through the lower part of the casing using a microscope such as an inverted microscope, it is desirable that the transmittance of the light having a wavelength of 450 to 750 nm of the casing unit 62 is 70% or more. . If the transmittance is less than 70%, it is difficult to measure the fluorescence of the droplet from the outside of the measurement cell 1, which is not preferable.

<Configuration example of droplet trapping device>
FIG. 3 is a diagram illustrating a schematic configuration example of the droplet capturing apparatus 200 according to the present embodiment. The droplet capturing apparatus 200 includes, for example, an installation unit 201 that installs the measurement cell 1, a sample holding unit 202 that holds a sample container (eg, a disposal tube) 211, and a flow rate control unit 203 that controls the oil flow rate. Have. The installation unit 201 is not particularly limited as long as the measurement cell 1 can be installed (fixed), and may include a mechanism for vibrating the measurement cell 1 or a mechanism for tilting the installed measurement cell 1. The sample holder 202 is not particularly limited as long as it has a structure capable of fixing the sample container 211 that holds oil and droplets, and may have a mechanism for vibrating the container that holds oil and droplets. good. The flow rate control unit 203 has a function of supplying oil to the sample container via the mutually connected channel 212, the measurement cell 1, and the channel 213, or the mutually connected channel 213, the measurement cell 1, and the channel 212. There is no particular limitation as long as it has a function of sucking oil via the.

<Operation of Droplet Capture Device 200>
FIG. 4 is a diagram schematically illustrating an operation example of the droplet capturing apparatus 200 according to the present embodiment. First, the measurement cell 1 and the sample container 211 are installed in the installation unit and the sample holding unit, respectively, and the flow rate control unit 203 transfers to the sample container 211 via the flow channel 212, the measurement cell 1, and the flow channel 213 connected to each other. Oil 102 is supplied (see FIG. 4A). FIG. 4B shows a state after the oil supply. Thereafter, the required amount of droplets 101 is added to the oil in the sample container 211. After this operation, the droplet 101 may be dispersed in the oil 102 using a function of vibrating the sample container 211 provided in the sample holding unit. FIG. 4C shows a state after the droplet 101 is added to the oil 102. Thereafter, while continuing to vibrate the sample holding unit 202, the droplet dispersion liquid in the sample container 211 is sucked using the flow rate control unit 203 via the flow path 213, the measurement cell 1, and the flow path 212. The droplet 101 is introduced into the measurement cell 1. When the droplet 101 is introduced into the measurement cell 1, the droplet 101 is captured in the chamber portion 2 by buoyancy, and further captured by the wells 23 in the droplet guide portion 21 by buoyancy and arranged. At this time, the arrangement of the droplets 101 may be promoted by exciting the measurement cell by the vibration of the installation unit 201. Further, the arrangement of the droplets 101 may be promoted by inclining the measurement cell 1 by inclining the installation portion 201. FIG. 4D shows a state after the droplets 101 are arranged.
Through the above operation, the droplet capturing apparatus 200 arranges the droplets in the measurement cell 1.

<Examples and comparative examples>
Hereinafter, examples and comparative examples according to the present disclosure will be described. The comparative example is a result obtained by the method disclosed in Non-Patent Document 1.

  FIG. 5 is a diagram illustrating an example of the structure of each measurement cell used in Examples and Comparative Examples. These measurement cells were prepared by laminating a slide glass (S1111 made by Matsunami Glass Industry) and an adhesive sheet (9969 made by 3M). The width of the flow path was 1 mm and the height was 100 μm. In addition, the depth of the chamber portion of the measurement cell used in the example (the minimum distance between the droplet guide surface 21 and the flow path 4) was 75 μm. The droplet guide surface was prepared using the optical nanoimprint method. As a material constituting the droplet guide surface, a mixture (1: 2) of photocrosslinkable polyurethane (EB8405 manufactured by Daicel Cytec Co., Ltd.) and a photocrosslinker (A-NPG manufactured by Shin-Nakamura Chemical Co., Ltd.) was used.

  FIG. 6 is a diagram showing the structure of the droplet guide surface of each measurement cell used in the examples and comparative examples. The diameter R of the well 23 was 20.5 μm, and the depth d of the well was 18 μm. The wells were arranged in a triangle, and the shortest pitch between the wells was 25 μm.

  In each of the present example and the comparative example, a droplet (particle diameter: 20 μm) produced using a RainDrop System made by RainDance was used, and a carrier oil made by RainDance was used as the oil. The droplets added to the oil floated on the oil.

(1) Example 1 and Comparative Example 1
In the first embodiment, first, the measurement cell 1 and the sample container 211 are installed in the installation unit 201 and the sample holding unit 202, respectively, and flow rate control is performed via the channel 212, the measurement cell 1, and the channel 213 connected to each other. 400 μL of oil was supplied from the unit 203 to the sample container 211 (flow rate: 1 ml / min). Thereafter, 1.0 μL droplets were added to the oil in the sample container 211 using a micropipette, and the droplets were dispersed in the oil using the vibration function of the sample holding unit 202. In Example 1, a block bath shaker (MyBL-100CS manufactured by ASONE, frequency 600 rpm) was used as the sample holder 202. Thereafter, while continuing the excitation of the sample holding unit 202, the liquid droplet dispersion in the sample container 211 is sucked using the flow rate control unit 203 via the channel 213, the measurement cell 1, and the channel 212 ( The liquid droplet was introduced into the measurement cell 1 while vibrating the measurement cell 1 using the vibration function of the installation unit 201 at a flow rate of 0.1 ml / min. In Example 1, a block bus shaker (MyBL-100CS manufactured by ASONE, frequency 600 rpm) was used as the installation unit 201. Through the above operation, the droplets were arranged in the measurement cell 1. When the droplets were observed using an optical microscope, the droplets were regularly arranged according to the wells. Further, as a result of obtaining the number of droplets present on the droplet guide surface from the optical microscope image, it was found that 3 × 10 ⁴ droplets were captured.

On the other hand, in Comparative Example 1, first, the measurement cell 1 and the sample container 211 are installed in the installation unit 201 and the sample holding unit 202, respectively, and the channel 212, the measurement cell 1, and the channel 213 are connected to each other. 400 μL of oil was supplied from the flow rate control unit 203 to the sample container 211 (flow rate: 1 ml / min). Thereafter, 1.0 μL droplets were added to the oil in the sample container 211 using a micropipette, and the droplets were dispersed in the oil using the vibration function of the sample holding unit 202. In Example 1, a block bath shaker (MyBL-100CS manufactured by ASONE, frequency 600 rpm) was used as the sample holder 202. Thereafter, while continuing the excitation of the sample holding unit 202, the liquid droplet dispersion in the sample container 211 is sucked using the flow rate control unit 203 via the channel 213, the measurement cell 1, and the channel 212 ( The liquid droplet was introduced into the measurement cell 1 while vibrating the measurement cell 1 using the vibration function of the installation unit 201 at a flow rate of 0.1 ml / min. In this example, a block bath shaker (MyBL-100CS manufactured by ASONE, vibration frequency 600 rpm) was used as the installation unit 201. Through the above operation, the droplets were arranged in the measurement cell 1. When the droplets were observed using an optical microscope, the droplets were regularly arranged according to the wells. Further, as a result of obtaining the number of droplets present on the droplet guide surface from the optical microscope image, it was found that 5 × 10 ³ droplets were captured.

(2) Example 2
In Example 2, a droplet (diameter 20 μm) containing a DNA molecule (100 nM) modified with a fluorescent dye (FAM) was prepared using a RainDrop System RainDrop System. Thereafter, following the same procedure as in Example 1, the droplets were arranged in the measurement cell.

  Next, the fluorescence image of the arranged droplets was observed. FIG. 7 is a diagram schematically showing a measurement system in which a fluorescence image of the array droplets in the measurement cell is observed. In this observation, light emitted from the light source 301 was reflected by the dichroic mirror 302, and the measurement cell 1 installed in the measurement cell installation unit 308 was irradiated through the objective lens 303. The fluorescence emitted from the droplets by the light irradiation passed through the objective lens 303, the dichroic mirror 302, the imaging lens 304, the long pass filter 305, and the band pass filter 306, and formed an image on the surface of the light receiving element of the camera 307. FIG. 8 shows the result of measuring the fluorescence image of the arrayed droplets in the measurement cell using the measurement system of FIG. From this figure, it was found that the fluorescence image of the arranged droplets can be observed using the optical system.

(3) Consideration about the result by an Example, and the result by a comparative example From the comparison of Example 1 and Comparative Example 1, the number of the droplets which exist in the droplet guide surface of Example 1 is 6 compared with Comparative Example 1. I found that it was about twice as many. From the above, it has been found that the droplet capture rate can be greatly improved by the technique of the present disclosure. Further, from Example 2, it was found that the fluorescence image of the droplets arranged in the measurement cell can be observed.

<Summary>
(I) In the present embodiment, the space from the bottom surface of the flow path extending from the fluid inlet (introduction section 3) to the oil discharge outlet (oil discharge section 5) to the droplet guide surface having a plurality of wells is the flow path. Using a measurement cell (chamber structure) that constitutes a chamber set higher than the height, a fluid containing a plurality of droplets and oil in the measurement cell with the droplet guide surface facing up is used as a flow path. Shed. In the chamber portion, a plurality of droplets are captured in a plurality of wells on the droplet guide surface by using the buoyancy of the droplets with respect to oil. Thus, by capturing a droplet using a measurement cell having a chamber structure, it is possible to capture the droplet efficiently and with high probability in the well of the droplet guide surface (improvement of capture rate). Furthermore, the measurement cell may be vibrated to promote the arrangement of a plurality of droplets on the droplet guide surface. As a result, the capture rate can be further improved.

(Ii) The measurement cell according to the present embodiment is in contact with a droplet guide surface having a plurality of wells on one inner wall surface of the internal space, a surface common to the droplet guide surface, and in a direction opposite to the concave side of the well An inner wall provided, a flow path formed between the chamber part and the plane by a plane provided on the lower side of the chamber part so as to face the droplet guide surface, oil, , A liquid droplet having a lighter specific gravity than oil, and an introduction portion for introducing the droplet into the flow path, and an oil discharge portion for discharging the oil to the outside. By doing so, in the chamber portion, the droplets can be aligned by their buoyancy, can be reliably guided to each well of the droplet guide surface, and more droplets can be captured. (Improvement of capture rate). In order to further improve the capture rate, the plurality of wells are preferably arranged in a plane on the droplet guide surface.

  Further, when the average diameter of the droplets is D [μm] and the minimum distance between the droplet guide surface and the channel (distance between the droplet guide surface and the channel upper surface) is L [μm], 20 μm ≦ D ≦ The measurement cell is configured to satisfy 100 μm and L ≧ 2D. This is because when L is smaller than 2D, the droplets that have flowed into the chamber portion through the flow path cannot be sufficiently captured.

  Further, when the shortest distance between the well and the inner wall of the droplet guide surface is W [μm], the measurement cell is configured to satisfy 20 μm ≦ D ≦ 100 μm and W ≦ 5D. This is because if the distance between the common surfaces is greater than 5D, a large number of liquid droplets that are not captured by the well and remain on the common surface are generated, which may hinder the improvement of the capture rate.

In the measurement cell of this embodiment, at least a part of the side surface (inner wall 22) of the chamber portion is a curved surface. More specifically, the horizontal cross-sectional shape of the chamber portion is elliptical or circular. By doing so, the fluidity of the droplet can be improved.
Further, in the measurement cell of the present embodiment, the transmittance of light having a wavelength of 450 to 750 nm is 70% or more in the casing part sandwiched between the droplet guide surface and the outer periphery of the measurement cell. By doing so, the fluorescence from the droplet can be measured efficiently.

DESCRIPTION OF SYMBOLS 1 Measurement cell 2 Chamber part 3 Introduction part 4 Flow path 5 Oil discharge part 21 Droplet guide surface 22 Inner wall 23 Well 24 Common surface 61 Case part 62 Case part 101 Droplet 102 Oil 200 Droplet trapping device 201 Installation part 202 Sample holding unit 203 Flow rate control unit 211 Sample container 212 Channel 213 Channel 301 Light source 302 Dichroic mirror 303 Objective lens 304 Imaging lens 305 Long pass filter 306 Band pass filter 307 Camera 308 Measurement cell installation unit

Claims (12)

A chamber having a droplet guide surface having a plurality of wells on one inner wall surface of the internal space, and an inner wall in contact with a surface common to the droplet guide surface and provided in a direction opposite to the concave side of the well Section, a flow path formed between the chamber section and the plane, oil, and a specific gravity greater than that of the oil by a plane provided on the lower side of the chamber section so as to face the droplet guide surface Preparing a measurement cell comprising: a light droplet; an introduction part for introducing the light droplet into the flow path; an oil discharge part for discharging the oil to the outside; and a housing part;
Flowing a fluid containing a plurality of droplets and oil through the flow channel in the measurement cell with the droplet guide surface facing upward;
Capturing the plurality of droplets in the plurality of wells of the droplet guide surface using buoyancy of the droplets with respect to the oil in the chamber portion; and
A method for capturing droplets. In claim 1,
Furthermore, the droplet capturing method includes the step of oscillating the measurement cell to promote the arrangement of the plurality of droplets on the droplet guide surface. A chamber having a droplet guide surface having a plurality of wells on one inner wall surface of the internal space, and an inner wall in contact with a surface common to the droplet guide surface and provided in a direction opposite to the concave side of the well And
A flow path formed between the chamber portion and the plane by a plane provided on the lower side of the chamber portion so as to face the droplet guide surface;
An introduction part for introducing oil and droplets having a lighter specific gravity than oil into the flow path;
An oil discharge part for discharging the oil to the outside;
A measuring cell. In claim 3,
The plurality of wells are measurement cells arranged in a plane on the droplet guide surface. In claim 3,
A measurement cell that satisfies the relationship of the following formulas (1) and (2), where D is an average diameter of the droplets and L is a minimum distance between the droplet guide surface and the flow path. .
20 μm ≦ D ≦ 100 μm (1)
L ≧ 2D (2) In claim 3,
When the average diameter of the droplet is D [μm] and the shortest distance between the well of the droplet guide surface and the inner wall is W [μm], the relationship of the following formulas (1) and (3) is satisfied. Measuring cell.
20 μm ≦ D ≦ 100 μm (1)
W ≦ 5D (3) In claim 3,
A measurement cell in which at least a part of the shape of the void portion when the chamber portion is cut along a plane parallel to the droplet guide surface forms a curve. In claim 7,
The shape of the void part is a measurement cell which is elliptical or circular. In claim 3,
A measurement cell in which the transmittance of light having a wavelength of 450 to 750 nm is 70% or more in a casing part sandwiched between the droplet guide surface and the outer periphery of the measurement cell. An apparatus for capturing droplets,
An installation section for installing the measurement cell according to claim 3;
A sample holder having a mechanism for dispersing droplets before injection in a solvent;
A flow rate controller for controlling the injection speed of the liquid droplet dispersion;
A droplet trapping device comprising: In claim 10,
A droplet trapping device, wherein the installation part has a vibration mechanism. In claim 10,
A droplet trapping device in which the sample holder has a vibration mechanism.

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