JP2020056588A - Pore chip case and fine particle measurement system - Google Patents

Abstract

To provide a pore chip case with improved contact certainty.SOLUTION: A pore chip case 800 stores a pore chip 102. A body 810 includes a first space 812 and a second space 814 that are divided by the pore chip 102. A first electrode 830 is extended in a vertical direction and fitted into the body 810 in a state where one end can be immersed in a liquid in the first space 812. The body 810 has a first insertion port 816 that horizontally communicates with a part of the first electrode 830 from a side surface S1.SELECTED DRAWING: Figure 4

Description

  The present invention relates to measurement using a pore device.

  A particle size distribution measuring method called an electrical detection band method (the Coulter principle) is known. In this measurement method, an electrolyte containing particles is passed through pores called nanopores. As the particles pass through the pores, the electrolyte in the pores decreases by an amount corresponding to the volume of the particles, increasing the electrical resistance of the pores. Therefore, by measuring the electric resistance of the pores, it is possible to measure the volume of the passing particles when the thickness of the pores is larger than the particles, and when the thickness of the pores is sufficiently smaller than the particles. The cross-sectional area (ie, particle size) of the passing particles can be measured.

  FIG. 1 is a block diagram of a particle measurement system 1R using the electric detection band method. The particle measurement system 1R includes a pore device 100, a measurement device 200R, and a data processing device 300.

  The inside of the pore device 100 is filled with the electrolyte solution 2 containing the particles 4 to be detected. The interior of the pore device 100 is separated by a pore tip 102 into two spaces, and an electrode 106 and an electrode 108 are provided in the two spaces. When a potential difference is generated between the electrodes 106 and 108, an ionic current flows between the electrodes, and the particles 4 move from one space to the other space via the pores 104 by electrophoresis.

  The measurement device 200R generates a potential difference between the electrode pairs 106 and 108, and acquires information having a correlation with the resistance value Rp between the electrode pairs. Measurement device 200R includes transimpedance amplifier 210, voltage source 220, and digitizer 230. The voltage source 220 generates a potential difference Vb between the electrode pairs 106 and 108. This potential difference Vb serves as a driving source for electrophoresis and also serves as a bias signal for measuring the resistance value Rp.

A small current Is that is inversely proportional to the resistance of the pore 104 flows between the electrode pairs 106 and 108.
Is = Vb / Rp (1)

The transimpedance amplifier 210 converts the small current Is into a voltage signal Vs. When the conversion gain is r, the following equation holds.
Vs = −r × Is (2)
By substituting equation (1) into equation (2), equation (3) is obtained.
Vs = −Vb × r / Rp (3)
The digitizer 230 converts the voltage signal Vs into digital data Ds. As described above, the voltage signal Vs that is inversely proportional to the resistance value Rp of the pore 104 can be obtained by the measuring device 200R.

  FIG. 2 is a waveform diagram of an exemplary minute current Is measured by the measurement device 200R. Note that the vertical and horizontal axes of the waveform diagrams and time charts referred to in this specification have been appropriately enlarged or reduced for easy understanding, and the waveforms shown are also simplified for easy understanding. Or exaggerated or emphasized.

  The resistance value Rp of the pore 104 increases for a short period of time when the particles pass. Therefore, the current Is decreases in a pulsed manner each time a particle passes. The amplitude of each pulse current correlates with the particle size. The data processing device 300 processes the digital data Ds and analyzes the number, the particle size distribution, and the like of the particles 4 included in the electrolytic solution 2.

JP 2017-016881 A JP 2014-219235 A JP 2018-054594 A WO 2002/084306

  FIG. 3 is a cross-sectional view of the pore device studied by the present inventors. The pore device 100R is provided with two electrodes E1 and E2 corresponding to the electrode pairs 106 and 108. The electrodes E1 and E2 are electrode rods and electrode plates. One electrode E1 is inserted into a space above the pore tip 102, and the other electrode E2 is inserted into a space below the pore tip 102.

  The electrodes E1 and E2 protrude vertically upward from the upper surface of the pore device 100R. The measuring device has a clip-type probe 201 as an interface with the pore device 100R. The operator of the particle measurement system 1 sandwiches the electrodes E1 and E2 with the clip-type probe 201 and makes electrical contact between the pore device 100R and the transimpedance amplifier 210.

  The clip-type probe has an advantage that there is little restriction on the shape of the electrode to be connected, but is susceptible to mechanical vibration and is likely to cause poor contact. In addition, since the position of the probe 201 may change each time it is attached, reproducibility of measurement is poor.

  The present invention has been made in such a situation, and one of the exemplary purposes of one embodiment of the present invention is to provide a pore tip case with improved contact reliability.

  One embodiment of the present invention relates to a pore tip case that accommodates a pore tip. A pore tip case, a body having a first space and a second space defined by the pore tip, a first electrode extending in a vertical direction, and having one end fitted into the body in a state in which one end can be immersed in a liquid in the first space; Is provided. The body is provided with a first insertion port communicating in a horizontal direction from the side surface to a part of the first electrode.

  It is to be noted that any combination of the above-described components and any replacement of the components and expressions of the present invention between methods, apparatuses, and the like are also effective as embodiments of the present invention.

  According to an embodiment of the present invention, the reliability of the contact can be improved.

FIG. 3 is a block diagram of a particle measurement system using an electric detection band method. FIG. 4 is a waveform diagram of an exemplary minute current Is measured by a measuring device. It is sectional drawing of the pore device which the present inventors examined. FIGS. 4A and 4B are cross-sectional views of the pore tip case according to the first embodiment viewed from different directions. It is a perspective view showing a pore tip case and a receptacle. It is a figure showing the state where the pore tip case was attached to the receptacle. FIG. 7A is a cross-sectional view of the chip cover according to the second embodiment, and FIG. 7B is an exploded perspective view. FIGS. 8A and 8B are cross-sectional views of the pore tip case according to the second embodiment as viewed from different directions.

  Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in each drawing are denoted by the same reference numerals, and the repeated description will be omitted as appropriate. In addition, the embodiments do not limit the invention, but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

  In this specification, “the state in which the member A is connected to the member B” means that the member A and the member B are physically directly connected, and that the member A and the member B It does not substantially affect the actual connection state, or does not impair the function or effect exerted by the combination thereof, and also includes the case where the connection is made indirectly via another member.

  Similarly, “the state in which the member C is provided between the member A and the member B” means that the member A and the member C or the member B and the member C are directly connected, Indirect connection via another member that does not substantially affect the actual connection state or impair the function or effect provided by the combination thereof.

  In addition, dimensions (thickness, length, width, and the like) of each member described in the drawings may be appropriately enlarged or reduced in order to facilitate understanding. Furthermore, the dimensions of a plurality of members do not necessarily represent the magnitude relationship between them. Even if a member A is drawn thicker than another member B in the drawing, the member A It could be thinner.

  In some cases, the cross-sectional views in this specification show the position of each member moved on an XY plane.

(Example 1)
FIGS. 4A and 4B are cross-sectional views of the pore chip case 800 according to the first embodiment viewed from different directions. The pore tip case 800 houses the pore tip 102.

  The x, y axes are horizontal in use and the z axis is vertical in use. The body 810 has a first space 812 and a second space 814 defined by the pore tip 102. In use, the first space 812 is filled with fine particles (analyte to be measured) and an electrolyte solution. The second space 814 is filled with an electrolyte solution.

  The first electrode 830 extends in the vertical direction (z direction), and one end of the first electrode 830 is fitted into the body 810 so as to be immersed in the liquid in the first space 812. The second electrode 832 extends in the vertical direction, and one end of the second electrode 832 is fitted into the body 810 so as to be immersed in the liquid in the second space 814. As the first electrode 830 and the second electrode 832, an electrode rod can be used, but not limited thereto, and a plate-like electrode may be used.

  The body 810 is separable into a first portion 810A and a second portion 810B to replace the pore tip 102. The first portion 810A may be referred to as a lid, and the second portion 820B may be referred to as a container.

  The body 810, more specifically, the first portion 810A is provided with a first insertion port 816 and a second insertion port 818. The first insertion port 816 communicates in the horizontal direction (x direction) from the side surface S1 of the body 810 to a part of the first electrode 830. Similarly, the second insertion port 818 communicates in a horizontal direction (x direction) from the side surface S1 of the body 810 to a part of the second electrode 832.

  The first insertion port 816 and the second insertion port 818 may be provided on the same side surface S1 of the body 810.

  The above is the configuration of the pore chip case 800. Subsequently, an interface (receptacle) on the main body side of the measuring device 200 that forms a pair with the pore chip case 800 will be described.

  FIG. 5 is a perspective view showing the pore tip case 800 and the receptacle 900. Receptacle 900 can be fitted with pore tip case 800.

  Receptacle 900 has a surface S2 facing one side S1 of pore chip case 800. From this surface S2, the first probe 902 and the second probe 904 project in the horizontal direction. The position of the first probe 902 is provided at a position corresponding to the first insertion port 816, and similarly, the position of the second probe 904 is provided at a position corresponding to the second insertion port 818.

  As the first probe 902 and the second probe 904, a contact probe with a built-in spring can be used, and the distal ends thereof can be moved according to the pressure.

  A positioning guide 908 may be provided on the surface of the base 906 and the bottom of the pore chip case 800.

  FIG. 6 shows a state in which the pore tip case 800 is mounted on the receptacle 900. A lock mechanism 910 is provided on the base 906, and the pore tip case 800 is fixed so as not to move.

  According to the interface including the pore tip case 800 and the receptacle 900, the tip of the first probe 902 contacts a predetermined portion of the first electrode 830, and the tip of the second probe 904 contacts the predetermined portion of the second electrode 832. Is guaranteed to contact with. Therefore, the reproducibility of the measurement can be improved. Further, compared to the case where a clip-type probe is used, it is more resistant to mechanical vibration and less likely to cause poor contact.

  Further, since the first electrode 830 and the second electrode 832 are fitted into the body 810, they are not easily deformed when the first probe 902 and the second probe 904 are brought into contact. Therefore, it can be said that the electrode is hardly deteriorated, which contributes to prolonging the life of the pore chip case 800.

(Example 2)
In the second embodiment, the pore chip 102 is housed in the pore chip case 800A while being covered with the chip cover 120. FIG. 7A is a cross-sectional view of the chip cover 120 according to the second embodiment, and FIG. 7B is an exploded perspective view. The chip cover 120 includes an upper chip cover 122 and a lower chip cover 124, and has a structure that sandwiches the pore chip 102 therebetween. The upper chip cover 122 is provided with an opening 126 provided at a position overlapping the pore 104 of the pore chip 102. This opening 126 corresponds to the first space 812 described above.

  The lower chip cover 124 is provided with a concave portion 128 provided at a position overlapping the small hole 104. The recess 128 corresponds to the second space 814 described above. The recess 128 is connected to the injection port 132 via the channel 130. A cutout 134 or an opening is provided in a portion of the upper chip cover 122 that overlaps with the injection port 132.

  At the time of measurement, the electrolyte solution and the analyte are injected into the opening 126 (first space 812), and the electrolyte solution is injected from the injection port 132 into the concave portion 128 (second space 814).

  FIGS. 8A and 8B are cross-sectional views of the pore chip case 800A according to the second embodiment viewed from different directions. The pore chip case 800A accommodates the chip cover 120 of FIG. The tip of the first electrode 830 is immersed in the liquid at the opening 126, and the tip of the second electrode 832 is immersed in the liquid at the notch 134 or the inlet 132.

  The first electrode 830 and the second electrode 832 are exchangeably inserted from the upper surface of the first portion 810A of the body 810. A screw hole is provided on the side surface of the first portion 810A. The first electrode 830 (second electrode 832) is fixed by tightening the screw 840 (842) into the screw hole. With this structure, the first electrode 830 (the second electrode 832) can be fixed at an arbitrary height (depth).

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it is understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and that such modifications are also within the scope of the present invention. is there. Hereinafter, such modifications will be described.

  In the embodiment, the case where both the first electrode 830 and the second electrode 832 are in contact with the probes 902 and 904 inserted into the first insertion port 816 and the second insertion port 818 from the side has been described. Not. One of them may be configured to contact in another manner. For example, one electrode may be formed on the pore chip 102, the upper chip cover 122, and the lower chip cover 124, and the probe may be brought into contact with this electrode.

  Although the present invention has been described with reference to a particle measuring apparatus, the application of the present invention is not limited thereto, and the present invention can be widely used for a measuring instrument that involves microcurrent measurement using a pore device such as a DNA sequencer.

  Although the present invention has been described based on the embodiments, the embodiments merely show the principles and applications of the present invention, and the embodiments depart from the spirit of the present invention defined in the claims. Many modifications and changes in arrangement are recognized within a range not to be performed.

DESCRIPTION OF SYMBOLS 1 Particle measuring system 2 Electrolyte 4 Particle 100 Pore device 200 Measuring device 210 Transimpedance amplifier 220 Voltage source 230 Digitizer 300 Data processing device 100 Pore device 102 Pore chip 104 Micropore 120 Chip cover 122 Upper chip cover 124 Lower chip cover 800 Pore Chip case 810 Body 810A First part 810B Second part 812 First space 814 Second space 816 First insertion port 818 Second insertion port 830 First electrode 832 Second electrode 900 Receptacle 902 First probe 904 Second probe 906 Base 908 Guide 910 Lock mechanism 128 Recess 132 132 Inlet 126 Opening

Claims (8)

A pore tip case for accommodating the pore tip,
A body having a first space and a second space defined by the pore tip;
A first electrode that extends in the vertical direction and has one end fitted into the body in a state where the one end can be immersed in a liquid in the first space;
With
A pore chip case, wherein the body is provided with a first insertion opening communicating in a horizontal direction from one side surface to a part of the first electrode. A second electrode that extends in the vertical direction and has one end fitted into the body in a state where the one end can be immersed in a liquid in the second space;
2. The pore chip case according to claim 1, wherein the body is provided with a second insertion opening communicating in a horizontal direction from one side surface to a part of the second electrode. 3.   The pore tip case according to claim 2, wherein the first insertion port and the second insertion port are provided on the same side surface of the body.   4. The pore tip case according to claim 2, wherein the first electrode and the second electrode are electrode rods. 5.   The pore chip case according to any one of claims 2 to 4, wherein the first electrode and the second electrode are insertable from an upper surface of the body.   The pore tip case according to claim 5, wherein each of the first electrode and the second electrode is fixed by a screw inserted from a side surface of the body.   The pore chip case according to claim 1, wherein the pore chip is housed in the pore chip case while being covered with a pore cover. A pore device comprising the pore tip and the pore tip case according to any one of claims 1 to 7, which accommodates the pore tip,
A measuring device having an interface socket to which the pore device is mounted,
A fine particle measurement system comprising:

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