Test cartridge

Abstract

To perform efficient and highly accurate inspection.SOLUTION: The inspection cartridge according to the present embodiment includes a reaction tank, a housing, and a blocking unit. The reaction tank contains a droplet. The housing includes an opening portion including a storage portion capable of storing the liquid droplet before the liquid droplet flows into the reaction tank, and one or more vent holes for discharging air in the reaction tank. The closing portion is formed to be capable of closing and opening the one or more vent holes.SELECTED DRAWING: Figure 7C

Description

[Technical Field]

[0001] The embodiments disclosed in this specification and drawings relate to a test cartridge. [Background technology]

[0002] In infectious disease testing and blood testing, an optical sensor that detects the amount of a target substance as an optical change is used as an example of a testing method. In an optical sensor, the target substance is measured by sending a sample to a space (also called a reaction chamber) formed between an optical waveguide layer and the opposing surface of the optical waveguide layer using a dropping device containing a detection reagent.

[0003] In ELISA (Enzyme-linked Immunosorbent Assay) using optical sensors, the so-called sandwich method is often used to increase detection sensitivity, in which an antigen is sandwiched between a solid-phase antibody and a liquid-phase antibody. In the sandwich method, when an antigen is added, competition for the antigen occurs between the solid-phase antibody and the liquid-phase antibody. The antigen that first binds to the solid-phase antibody is fixed and loses its degree of freedom, reducing the probability of it further reacting with the liquid-phase antibody to form a sandwich. Therefore, even if the detection time in the reaction vessel is extended, the desired effect cannot be achieved. Furthermore, if the reaction is carried out in advance in a location separate from the reaction tank where the solid-phase antibody is present in order to react only the antigen with the liquid-phase antibody, it is necessary to transfer the sample solution to the reaction tank after a predetermined time has elapsed, which results in the problem of complicated procedures, processes, and control. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-133836 [Patent Document 2] Patent No. 5424610 Summary of the Invention [Problem to be solved by the invention]

[0005] One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to measure a measurement target with high sensitivity. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described below can also be positioned as other problems. [Means for solving the problem]

[0006] The test cartridge according to this embodiment includes a reaction chamber, a housing, and a closing section. The reaction chamber contains droplets. The housing includes an opening including a reservoir capable of storing the droplets before they flow into the reaction chamber, and one or more vent holes for discharging air from within the reaction chamber. The closing section is configured to be able to close and open the one or more vent holes. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a block diagram showing an inspection system according to this embodiment. [Figure 2] FIG. 2 is a flowchart showing an example of a sample test performed by the test system according to this embodiment. [Figure 3] FIG. 3 is a diagram showing an example of time-series changes in the light intensity of emitted light according to this embodiment. [Figure 4] FIG. 4 is a diagram showing an example of the configuration of the sensor chip according to this embodiment. [Figure 5] FIG. 5 is a top view of the test cartridge according to this embodiment. [Figure 6] FIG. 6 is a cross-sectional view of the testing cartridge according to this embodiment taken along the line AA' in FIG. [Figure 7A] FIG. 7A is a diagram showing an example of a process of sending a sample liquid to a test cartridge according to this embodiment. [Figure 7B] FIG. 7B is a diagram showing an example of a process of sending a sample liquid to the test cartridge according to this embodiment. [Figure 7C] FIG. 7C is a diagram showing an example of a process of sending a sample liquid to the test cartridge according to this embodiment. [Figure 8] FIG. 8 is a table showing the specifications of the verification conditions for comparing the verification results between the method of dropping sample liquid using the test cartridge according to this embodiment and a conventional example. [Figure 9] FIG. 9 is a graph showing the verification results shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] The inspection cartridge according to this embodiment will be described below with reference to the drawings. In the following embodiments, parts with the same reference numerals perform similar operations, and redundant description will be omitted as appropriate.

[0009] The inspection system according to this embodiment will be described with reference to the block diagram of FIG. The test system includes a test cartridge 1 and an analysis device 3. The test cartridge 1 is detachable from the analysis device 3.

[0010] Here, a plurality of first antibodies are immobilized on the upper surface of an optical waveguide (not shown) located in the lower part of the test cartridge 1. The first antibodies are substances that react specifically with antigens contained in the detection target substance through an antigen-antibody reaction.

[0011] It is also assumed that the liquid (droplets) dropped into the test cartridge 1 is a mixture of a sample solution and a detection reagent (hereinafter referred to as the test solution). The sample solution contains a detection target substance (also referred to as an analyte) including an antigen. The detection reagent contains a reagent component capable of binding to the detection target substance. The reagent component includes, for example, a second antibody that specifically reacts with the antigen through an antigen-antibody reaction, and magnetic particles to which the second antibody is immobilized. The magnetic particles are at least partially formed of a magnetic material such as magnetite. For example, the magnetic particles are particles formed from a magnetic material, the surfaces of which are coated with a polymer material. Note that the magnetic particles may also be configured so that the surfaces of particles made of a polymer material are coated with a magnetic material. The magnetic particles may also be replaced by any material that is configured to be dispersible in the test solution.

[0012] The reagent components move dispersibly in the test solution filled in the reaction chamber of the test cartridge 1. Therefore, the magnetic particles are selected so that the gravity acting on the magnetic particles is greater than the buoyancy in the test solution that acts in the opposite direction to the gravity. The magnetic particles with the second antibody immobilized thereon are immobilized near the upper surface of the optical waveguide by the second antibody binding to the first antibody via the antigen. The second antibody may be the same as or different from the first antibody.

[0013] The analysis device 3 includes a detection unit 31, a magnetic field generator 32, an output unit 33, an input interface circuit , a memory circuit 35, and a system control circuit .

[0014] The detection unit 31 includes a light source 311 and a photodetector 312 . The light source 311 is a diode such as an LED (Light Emitting Diode) or a lamp such as a xenon lamp. The light source 311 is disposed at a position where it can emit light into the optical waveguide toward a grating (not shown) on the entrance side of the test cartridge 1. The light source 311 causes incident light L1 to enter the optical waveguide through the transparent substrate of the test cartridge 1. The incident light L1 enters the optical waveguide and is diffracted by the grating on the entrance side. The incident light L1 diffracted by the grating on the entrance side propagates through the optical waveguide while being totally reflected and reaches the grating on the exit side (not shown). The light that reaches the grating on the exit side is diffracted by the grating on the exit side and is emitted from the optical waveguide at a predetermined angle as exit light L2. Note that instead of the light source 311, a device that generates electromagnetic waves other than light may be used.

[0015] The photodetector 312 outputs an electrical signal based on the reaction state in the reaction vessel containing the test solution. Specifically, the photodetector 312 detects the output light L2 emitted from the optical waveguide and generates an electrical signal indicating the intensity of the detected output light L2, i.e., digital data relating to the detected light intensity. The digital data relating to the detected light intensity generated by the photodetector 312 is supplied to the system control circuit 36.

[0016] The magnetic field generator 32 applies a magnetic field to the reaction chamber of the test cartridge 1 under the control of the system control circuit 36, thereby accelerating the sedimentation of the magnetic particles in the reaction chamber or lifting the magnetic particles upward. The magnetic field generator 32 generates energy that promotes antigen-mediated binding between the second antibody immobilized on the magnetic particles and the first antibody immobilized on the upper surface of the optical waveguide. Specifically, the magnetic field generator 32 has an upper magnetic field generator and a lower magnetic field generator. The magnetic field generator 32 also has a drive circuit (not shown). The upper magnetic field generator and the lower magnetic field generator are each composed of, for example, a permanent magnet and an electromagnet.

[0017] The output unit 33 includes a display circuit 331 , an annunciator 332 , and a printer 333 . The display circuit 331 outputs data to a general external display device such as a liquid crystal display or an OLED (organic LED) display. Under the control of the system control circuit 36, the display circuit 331 displays various operation screens, information indicating the light intensity of the emitted light L2 supplied from the photodetector 312, time-series data of the information indicating the light intensity, and measurement results of the detection target substance. The measurement results are, for example, the concentration, weight, or number of antigens, i.e., a numerical value corresponding to the amount of antigens.

[0018] The annunciator 332 is, for example, a speaker. Under the control of the system control circuit 36, the annunciator 332 notifies the operator of operation timing, alarms, and the like.

[0019] Under the control of the system control circuit 36, the printer 333 prints, for example, various operation screens output from the display circuit 331, information indicating the light intensity of the emitted light L2 supplied from the photodetector 312, data of the information indicating the light intensity, and measurement results of the substance to be detected.

[0020] The input interface circuit 34 may be realized by, for example, a trackball, switch buttons, a mouse, a keyboard, a touchpad that performs input operations by touching the operation surface, or a touch panel display that integrates a display screen and a touchpad. The input interface circuit 34 outputs operation input signals corresponding to operations by the operator to the system control circuit 36. Note that, in this embodiment, the input interface circuit 34 is not limited to those that include physical operation components such as a mouse and a keyboard. For example, an example of an input interface circuit also includes an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device provided separately from the device and outputs this electrical signal to the system control circuit 36.

[0021] The memory circuitry 35 has a processor-readable recording medium, such as a magnetic or optical recording medium or a semiconductor memory. The memory circuitry 35 stores a program to be executed by the circuitry of the analyzer 3 according to this embodiment. Note that some or all of the programs and data stored in the storage medium of the memory circuitry 35 may be configured to be downloaded via an electronic network.

[0022] The memory circuit 35 stores information indicating the light intensity of the emitted light L2 supplied from the photodetector 312, time-series data of the information indicating the light intensity, and the measurement results of the detection target substance to be measured.

[0023] The memory circuitry 35 is a storage medium such as a hard disk drive (HDD) or a solid state drive (SSD), and stores setting information for measuring target substances. The setting information includes, for example, information specifying the timing of executing predetermined processes required for measurement. Examples of the timing of executing predetermined processes required for measurement include the timing at which application of the lower magnetic field starts, the timing at which application of the lower magnetic field stops, the timing at which application of the upper magnetic field starts, and the timing at which determination is performed. The information specifying these timings includes the relative time elapsed from a predetermined time or the absolute time at which the predetermined process is executed. Note that the relative time elapsed from a predetermined time or the absolute time at which the predetermined process is executed may be empirically or experimentally determined and set in advance.

[0024] The memory circuit 35 stores a preset threshold T A The threshold T A is the threshold value for the light intensity corresponding to the concentration of the substance to be detected. A is used to determine the qualitative state of the substance to be detected. The qualitative state is, for example, the degree of positivity or negativity indicated by the measurement result. The threshold T A is used to make a final judgment as to whether the measurement result of the substance to be detected is likely to be positive. Amay be a plurality of stepped thresholds. That is, by comparing the light intensity included in the digital data with a plurality of stepped thresholds, it becomes possible to make a determination that represents a more detailed measurement result.

[0025] The system control circuit 36 ​​is, for example, a processor that controls each component circuit of the analysis device 3. The system control circuit 36 ​​functions as the central part of the analysis device 3. The system control circuit 36 ​​calls each operation program from the memory circuit 35 and executes the called program to realize a light source control function 361, a magnetic field control function 362, a calculation function 363, a determination function 364, and an output control function 365.

[0026] The light source control function 361 controls the light source 311 to emit light under predetermined conditions. In the light source control function 361, the system control circuit 36 ​​causes the light source 311 to emit incident light L1 continuously or intermittently at least from the start to the end of measurement.

[0027] The magnetic field control function 362 controls the magnetic field generator 32 according to a time schedule pre-stored in the memory circuitry 35, and switches the state of application of energy to promote the reaction in the reaction vessel. Specifically, in the magnetic field control function 362, the system control circuitry 36 reads setting information from the memory circuitry 35, controls the magnetic field generator 32 based on the read setting information, and causes the magnetic field generator 32 to generate a magnetic field.

[0028] The calculation function 363 performs various calculations based on the time-series digital data of light intensity supplied from the photodetector 312. In the calculation function 363, the system control circuit 36 ​​uses the time-series digital data of light intensity supplied to perform calculations related to optical changes such as the average value of light intensity, the fluctuation rate of light intensity, and the integrated value of the fluctuation rate.

[0029] The determination function 364 generates a measurement result regarding the amount of the substance to be detected based on the digital data of light intensity supplied from the photodetector 312 during application of an upper magnetic field, which will be described later. Specifically, the determination function 364 determines the amount of the substance to be detected (amount of substance, concentration, etc.) based on the digital data of light intensity and determines a qualitative state such as "high possibility of positive result." In the determination function 364, the system control circuit 36 ​​reads setting information and a threshold value T A The system control circuit 36 ​​determines the qualitative state of the detection target substance in accordance with the execution timing included in the read setting information. The system control circuit 36 ​​determines whether the light intensity included in the supplied digital data of the time series of light intensity is equal to or exceeds the threshold value T A If the light intensity contained in the digital data is equal to or less than the threshold value T A If it is greater than this, for example, the measurement result of the detection target substance is determined to be weakly positive or negative.

[0030] The output control function 365 controls the output unit 33 to output the determination result, such as the qualitative state of the detection target substance, to the operator. In the output control function 365, the system control circuit 36 ​​controls the display circuit 331 or the printer 333 to present the determination result to the operator. Presentation includes displaying via a display and printing using a printer. The system control circuit 36 ​​controls the alarm 332 to notify the operator of the determination result. Notification includes notification by sound or the like.

[0031] Next, an example of sample testing using the testing system according to this embodiment will be described with reference to the flowchart of FIG.

[0032] In step S1, the test cartridge 1 is set in the analyzer 3 and the test solution is dripped into it. This fills the reaction chamber of the test cartridge 1 with the test solution. Note that a lower magnetic field may be applied by the magnetic field generator 32 at the same time that the test solution is dripped into the drip hole (opening) of the test cartridge 1. Alternatively, the magnetic field generator 32 may fluctuate the magnetic field by applying an upper magnetic field and a lower magnetic field alternately or randomly and intermittently. Applying a magnetic field in this manner can promote the droplets from falling into the reaction chamber, thereby shortening the time until the test solution is filled into the reaction chamber.

[0033] In step S2, light of a constant intensity is emitted from the light source 311 of the detection unit 31 toward the optical waveguide of the test cartridge 1, so that light of a constant intensity is incident on the optical waveguide. Note that light of a constant intensity is continuously incident from the light source 311.

[0034] The magnetic field generator 32 starts to apply the lower magnetic field. The light incident on the optical waveguide propagates through the optical waveguide while being totally reflected, and is emitted to the photodetector 312 via the transparent substrate.

[0035] When light propagates through an optical waveguide, near-field light (evanescent light) is generated on the upper surface of the optical waveguide. The area near the surface of the optical waveguide where near-field light can be generated in the reaction vessel is also called the sensing region. In the reaction vessel, the first antibody immobilized on the upper surface of the optical waveguide reacts with an antigen contained in the substance to be detected in the sample solution. The antigen also binds to the second antibody immobilized on magnetic particles contained in the reagent components. This holds the magnetic particles with the second antibody immobilized near the reaction detection region on the upper surface of the optical waveguide.

[0036] The light guided through the optical waveguide is scattered and absorbed by the magnetic particles fixed near the upper surface of the optical waveguide. As a result, the light guided through the optical waveguide is attenuated before exiting the optical waveguide. That is, the incident light L1 is attenuated according to the amount of antigen that binds the first antibody and the second antibody fixed to the magnetic particles, in other words, the amount of antigen contained in the reaction vessel.

[0037] The photodetector 312 receives the light emitted from the optical waveguide and supplies data on the light intensity to the system control circuit 36 ​​at predetermined time intervals.

[0038] In step S3, the magnetic field generator 32 begins applying a lower magnetic field under the control of the system control circuit 36. Specifically, the lower magnetic field generator, located below the test cartridge 1, generates a lower magnetic field to apply a vertically downward magnetic force to the magnetic particles in the reaction tank, accelerating their sedimentation. Due to the generated vertically downward magnetic field and gravity, the magnetic particles with the second antibody immobilized thereon align along the magnetic field lines and descend under the vertically downward force. The second antibody binds to the first antibody immobilized in the reaction detection region located on the underside of the reaction tank via the light source.

[0039] In step S4, the magnetic field generator 32, under the control of the system control circuit , stops applying the lower magnetic field at a predetermined timing.

[0040] In step S5, the magnetic field generator 32 begins applying an upper magnetic field under control of the system control circuit 36. Specifically, when the test cartridge 1 is set in the analyzer 3, the upper magnetic field generator is positioned above the test cartridge 1. The upper magnetic field generator generates an upper magnetic field to pull the magnetic particles vertically upward in the reaction tank. This vertically upward magnetic field causes magnetic particles modified with the second antibody that did not bind to the first antibody via the antigen to rise due to a vertically upward force. At this time, the upper magnetic field generator generates a magnetic field of a predetermined strength to selectively move unreacted magnetic particles away from the sensing region. In other words, by adjusting the strength of the magnetic field generated, the upper magnetic field generator can retain only the magnetic particles modified with the second antibody that bound to the first antibody via the antigen, which are fixed to the upper surface of the optical waveguide, in the sensing region.

[0041] In step S6, at the timing when the reaction in the reaction vessel is considered to have converged, the system control circuit 36 ​​acquires one value of the light intensity data continuously supplied from the photodetector 312 as a measurement value.

[0042] In step S7, the system control circuit 36 ​​uses the determination function 364 to determine whether the measurement value acquired in step S7 is equal to the threshold value T A For example, a positive or negative result is determined by comparing the results with the above.

[0043] In step S8, the output control function 365 causes the system control circuit 36 ​​to present or notify the user of the determination result.

[0044] Next, an example of the time series change in the light intensity of the emitted light will be described with reference to FIG. FIG. 3 is a graph C of the time series change in light intensity, with the vertical axis representing light intensity and the horizontal axis representing time.

[0045] When the reaction chamber of the test cartridge 1 is filled with the test solution, the measured light intensity increases. This is because the water-soluble film applied to the upper surface of the optical waveguide including the reaction detection region to prevent denaturation of the first antibody dissolves.

[0046] After that, when a lower magnetic field is applied, as described above, the magnetic particles with the second antibody immobilized in the test solution in the reaction vessel bind to the first antibody immobilized on the reaction detection area via the antigen. Furthermore, as the magnetic particles with the second antibody immobilized enter the sensing area one after another, the amount of scattering and absorbing material in the sensing area increases, and the light intensity decreases. The rate of decrease in light intensity decreases over time, and reaches a certain light intensity value, here A 01 At this point, the magnetic particles are connected in a chain-like fashion to form clusters. At this point, the number of magnetic particles in the sensing area appears to be reduced.

[0047] After that, when the application of the lower magnetic field is stopped, the magnetic particles on which the second antibody is immobilized are released from the lower magnetic field, and the clusters are dispersed by Brownian motion and begin to sediment naturally. Note that for a certain period after the application of the lower magnetic field is stopped, a so-called overshoot occurs, and the light intensity increases, and then decreases in a short period. Once the overshoot subsides, the light intensity decreases. This is because the amount of scattering and absorbing material increases as the magnetic particles on which the second antibody is immobilized enter the sensing region one after another, and the rate of decrease becomes large. After a certain period of time has passed, the natural sedimentation of the magnetic particles on which the second antibody is immobilized also converges, and a certain light intensity value, here light intensity value A 03 converges to.

[0048] Light intensity value A 03 When the magnetic particles converge to the sensing region, the magnetic particles with the second antibody immobilized thereon remain in the sensing region. When near-field light is generated on the upper surface of the optical waveguide while the magnetic particles remain in the sensing region, the magnetic particles remaining in the sensing region scatter and absorb the near-field light, attenuating it. In other words, the attenuation of the near-field light in the sensing region also attenuates the light guided within the optical waveguide. In other words, the more magnetic particles remain in the sensing region, the lower the intensity of the light output from the optical waveguide.

[0049] In the absence of a magnetic field, the magnetic particles remaining in the sensing area are not limited to those bound to the first antibody immobilized on the upper surface of the optical waveguide via the antigen to be measured and the second antibody immobilized on the magnetic particles. In other words, unreacted magnetic particles may also remain in the sensing area. Therefore, to accurately measure the concentration of the antigen contained in the target substance, it is necessary to move away from the sensing area magnetic particles with immobilized second antibodies that are not involved in the measurement, i.e., not bound to the antigen. Therefore, by applying an upper magnetic field, the unreacted magnetic particles are moved upward away from the sensing area and resuspended in the reaction vessel.

[0050] As a result, most of the magnetic particles that ultimately remain in the sensing area are formed by binding between the first antibody immobilized on the upper surface of the optical waveguide via the antigen and the second antibody via the antigen, and a certain light intensity value, here light intensity value A 02 The equilibrium state is reached at the light intensity value A 02 and threshold T A The result of the determination is obtained by comparing the above.

[0051] Next, an example of the configuration of the sensor chip 2 will be described with reference to Fig. 4. Fig. 4 is a diagram of the sensor chip 2 portion as viewed from above. The sensor chip 2 includes a reactive detection region 21, a non-reactive detection region 22, a grating 23a, and a grating 23b. The sensor chip 2 is a flat optical sensor chip used in sample testing using an optical detection method, and detects a detection target substance by attenuation of light.

[0052] The reaction detection region 21 is located in the center of the sensor chip 2, and is a region where antibodies are immobilized (applied) on the upper surface of the sensor chip 2 (upper surface of the optical waveguide). Here, two rows of reaction detection regions 21 are formed as two independent regions. Furthermore, the reaction detection regions 21 have a substance on their surfaces that binds to the detection target substance. The portion where the reaction detection regions are formed is also referred to as the detection surface.

[0053] The surface of the reaction detection area 21 is treated to have hydrophilicity. Hydrophilicity refers to the property of forming a contact angle with a liquid that is less than approximately 90 degrees. For example, the reaction detection area 21 may be coated with a hydrophilic film. The coating material may be, for example, a water-soluble polymer (such as a polysaccharide, a cellulose derivative, polyvinyl alcohol, polyacrylic acid, or a protein), or one or a mixture of these derivatives. Alternatively, the coating may be a water-soluble low-molecular-weight material (such as a sugar, a disaccharide, or a polyhydric alcohol), or one or a mixture of these derivatives. Furthermore, the coating may contain both a high-molecular-weight material and a low-molecular-weight material.

[0054] The non-reaction detection area 22 is a portion of the upper surface of the sensor chip 2 other than the reaction detection area 21. Specifically, it is an area that surrounds the reaction detection area 21 in each row so that each reaction detection area 21 is an independent area. The non-reaction detection area 22 is also formed to be hydrophobic (water-repellent). Hydrophobicity refers to the property of forming a contact angle with a liquid that is greater than approximately 90 degrees. Examples of hydrophobic materials include acrylic, epoxy, polyvinyl chloride, and acrylic. The non-reaction detection area 22 may be coated with, for example, one of these hydrophobic materials.

[0055] Since the liquid is repelled by the non-reactive detection region 22, the non-reactive detection region 22 serves to keep the test solution in the reactive detection region 21, which has hydrophilic properties.

[0056] The grating 23a has a structure that reflects (diffracts) light, and is disposed at a position where light is incident on the optical waveguide. The grating 23b has a structure that reflects (diffracts) light, and is disposed at a position that reflects the light in the optical waveguide to the outside.

[0057] Next, a top view of the test cartridge 1 according to this embodiment is shown in FIG. As shown in FIG. 5 , an opening 5, one or more vent holes 6, and a blocking portion 7 are formed on the top surface of the housing 11 of the test cartridge 1, i.e., on the outer surface side of the housing 11. The housing 11 is made of, for example, polyvinyl chloride and has hydrophobic properties. The opening 5 is an opening through which a test solution is dripped from a dripping device (not shown). The opening 5 also has a storage portion 51 formed on the outer surface side of the housing 11, with the opening area narrowing from the outer surface (top surface) of the housing 11 to the inner surface (bottom surface). The storage portion 51 can store the dripped droplets before they flow into the reaction chamber. In the above description, the droplets stored in the storage portion 51 are assumed to be test solution, which is a mixture of a sample solution and a detection reagent. However, the shape of the droplets is not particularly limited. For example, a prepared test solution may be stored, or a test solution may be prepared by mixing various solutions in the storage portion. A drip hole 52 for allowing droplets to flow into the reaction tank is formed in the lower surface of the reservoir 51. For ease of explanation, the opening formed in the upper surface of the housing 11 is shown by a solid line, and the opening of the drip hole 52 formed in the lower surface is shown by a dashed line. The opening of the reservoir 51 and the opening of the drip hole 52 are both rectangular, but may be other shapes such as circular.

[0058] The vent hole 6 is an opening for discharging air pushed out of the reaction chamber as the test cartridge 1 is filled with the test solution dropped from the opening 5 to the outside of the housing 11. Here, three vent holes 6 are formed, but the number may be two or less, or four or more. The number of vent holes 6 may be set, for example, according to the number of reaction detection regions and the number of non-detection reaction regions 23 sandwiched between the reaction detection regions. Specifically, if there are two reaction detection regions 21, there will be one non-reaction detection region 22 sandwiched between the reaction detection regions 21, and therefore at least three vent holes 6 may be formed.

[0059] A blocking portion 7 is formed on the upper surface of the ventilation hole 6. The blocking portion 7 is a member formed to be able to block (seal) and open one or more ventilation holes 6. Specifically, the blocking portion 7 is structured to be able to block one or more ventilation holes 6 and also to be able to open the ventilation holes 6 from a closed state by applying an external force at any timing. The blocking portion 7 may be, for example, a lid structure that can be opened and closed upward, or a lid structure that can slide horizontally. Alternatively, the blocking portion 7 may be structured such that the ventilation hole 6 is sealed with adhesive tape or the like, and the adhesive tape is peeled off to open the ventilation hole 6. When the lid structure is opened and closed upward or slid horizontally, the external force may be that the blocking portion 7 is mechanically operated by hand or a drive unit (not shown). In this way, the blocking portion 7 may have any structure as long as it is able to seal and open the ventilation hole 6.

[0060] Next, FIG. 6 shows a cross-sectional view of the test cartridge 1 taken along the line AA' in FIG. The test cartridge 1 has a configuration in which the sensor chip 2 is attached to the lower surface of the housing 11 via an adhesive part 4. A space is formed between the detection surface including the reaction detection region 21 of the sensor chip 2 and the lower surface of the housing 11 (the upper surface of the reaction chamber) facing the sensor chip 2, and this space serves as the reaction chamber 65. As described above, the storage part 51 of the opening 5 has a tapered shape in which the opening size narrows from the upper side of the opening 5, which corresponds to the upper surface of the housing 11, toward the drip hole 52 on the lower side. The drip hole 52 is assumed to have a size that allows the test solution to be smoothly delivered to the reaction chamber 65, and may have a diameter larger than that of the air vent 6, for example.

[0061] Between the vent hole 6 and the blocking portion 7, a bank structure 8 is formed, extending vertically from the outer surface of the housing 11 around the vent hole 6 so as to surround one or more vent holes 6. The bank structure 8 provides a gap between the vent hole 6 and the blocking portion 7. The bank structure 8 prevents liquid from leaking from the vent hole 6 to the upper surface of the housing 11 when the reaction vessel 65 is filled with droplets, by providing a gap between the vent hole 6 and the blocking portion 7. The bank structure 8 is also formed so that even if droplets flow out from the vent hole 6, they are confined to a predetermined area without spreading over a wide area. The bank structure 8 may be molded integrally with the housing or may be externally attached to the periphery of the vent hole 6. The bank structure 8 has a rectangular parallelepiped shape, but is not limited to this shape and may have various shapes that can prevent liquid leakage. For example, the bank structure 8 may be formed in a tapered shape, similar to the opening 5, with its volume decreasing from top to bottom. Here, the height of the bank structure 8 is the same as the top of the opening 5, but it is not limited to this and may be formed to any height as long as it can prevent liquid leakage.

[0062] The sensor chip 2 includes a transparent substrate and an optical waveguide, both of which are not shown. The transparent substrate is made of resin, optical glass, or the like, and passes light incident from the light source 311 to the optical waveguide. The transparent substrate also passes the light that has passed through the optical waveguide to the outside, i.e., toward the photodetector 312. The transparent substrate is made of a material with a different refractive index from the optical waveguide, and totally reflects the light at the interface with the optical waveguide. In other words, it serves as a cladding that confines the light within the optical waveguide. The transparent substrate also serves to physically protect the optical waveguide.

[0063] The optical waveguide is laminated on a transparent substrate, and light passes through it. That is, the optical waveguide plays a role similar to that of the core of an optical fiber. It is made of a material that transmits light, such as resin or optical glass. Examples of resin that can be used include phenolic resin, epoxy resin, and acrylic resin. A reaction detection area 21 is formed on the upper surface of the optical waveguide.

[0064] Next, an example of a liquid transfer method for the test cartridge 1 according to this embodiment will be described with reference to FIGS. 7A to 7C. 7A to 7C are cross-sectional views of the test cartridge 1 according to this embodiment shown in FIG. 6, and show the case where the sample liquid S is delivered to the test cartridge 1. FIG.

[0065] 7A shows an example in which the sample liquid S is dropped into the opening 5 by the dropping device. At this time, the closing part 7 of the test cartridge 1 is in a state in which the vent hole 6 is sealed.

[0066] 7B shows a state in which the sample liquid is stored in the storage portion 51 of the opening 5. Because the closure portion 7 seals the vent hole 6 and air remains in the reaction tank 65, the sample liquid S does not flow into the reaction tank 65 from the drip hole 52 and is stored in the storage portion 51. While the sample liquid S is stored in the storage portion 51, the antigen reacts with the liquid-phase antibody without the intervention of the solid-phase antibody.

[0067] FIG. 7C shows the state in which the closure 7 is moved to open the vent 6, allowing air to be expelled from the reaction chamber 65 through the vent 6 and allowing the sample solution S to flow into the reaction chamber 65. In the reaction chamber 65, the antigen and the liquid-phase antibody have already reacted, and the sample solution S then reacts with the solid-phase antibody immobilized in the reaction detection area 21. The timing for opening the closure 7 can be determined empirically, for example, at any time, such as 5 or 10 minutes, as long as sufficient time is available for the test substance containing the antigen to react with the liquid-phase antibody contained in the sample solution. The closure 7 may also be set to open automatically. For example, the closure 7 may be connected to a drive unit, and the drive unit may be controlled to move the closure 7 after a predetermined time has elapsed, thereby opening the vent 6.

[0068] Next, a comparison of verification results between the method of dropping sample liquid using the test cartridge 1 according to this embodiment and a conventional example will be described with reference to FIGS.

[0069] Figure 8 is a table showing the specifications of the verification conditions for the verification. In this verification example, SARS coronavirus antibodies were immobilized in the reaction detection area 21 of the test cartridge 1. The sample solution contained a SARS coronavirus recombinant protein (50 pg / mL) as the test substance and a SARS coronavirus antibody as the liquid-phase antibody. The measurement time was 5 minutes for the test substance and the liquid-phase antibody to pre-react in the reservoir, and 15 minutes for the measurement time until the test substance was detected from the test cartridge 1.

[0070] The verification conditions are as shown in the table in Fig. 8. Verification conditions No. 1 to No. 3 are for the conventional method, and verification condition No. 4 is for the dropping method using the test cartridge 1 according to this embodiment.

[0071] Specifically, under Verification Condition 1 (No. 1), the test substance and the liquid-phase antibody were not reacted in advance, and the measurement time was 15 minutes. Under Verification Condition 2 (No. 2), the test substance and the liquid-phase antibody were pre-reacted in the reaction chamber 65 of the test cartridge 1 for 5 minutes, followed by a 15-minute measurement. Under Verification Condition 3 (No. 3), the test substance and the liquid-phase antibody were pre-reacted in a microtube for 5 minutes, then transferred to the test cartridge using a dropper, and a 15-minute measurement was performed. Under Verification Condition 4 (No. 4), the test substance and the liquid-phase antibody were pre-reacted in the reservoir 51 for 5 minutes, after which the closure 7 and the vent 6 were opened, and the sample liquid was allowed to flow into the reaction chamber 65, followed by a 15-minute measurement.

[0072] The results of the verification under the conditions in Figure 8 are shown in the graph in Figure 9. In Figure 9, the horizontal axis shows each verification condition No. 1 to No. 4 shown in Figure 8, and the vertical axis shows the sensitivity value (%). The three plots for each verification condition show the sensitivity value obtained by measuring one reaction detection area three times in order to verify the variation (reproducibility) of the measurement results. Under Verification Condition 1, the sensitivity value was low. Under Verification Condition 2, the solid-phase antibody, liquid-phase antibody, and test substance coexist in the reaction chamber 65, resulting in competition for the test substance. Therefore, it is expected that the test substance that first bound to the solid-phase antibody will be immobilized on the solid surface and lose its freedom, reducing the probability (efficiency) of forming an immune complex with the liquid-phase antibody. Therefore, even though the measurement time was 20 minutes, including a 5-minute pre-reaction, the sensitivity value was low. Under Verification Condition 3, the test substance and liquid-phase antibody were allowed to react sufficiently in a microtube separate from the solid-phase antibody in the test cartridge 1. Therefore, the sensitivity value was higher than under Verification Conditions 1 and 2.

[0073] On the other hand, under verification condition 4 using the test cartridge 1 according to this embodiment, the test substance and the liquid-phase antibody were allowed to react sufficiently in the reservoir 51, which was independent of the solid-phase antibody of the test cartridge 1, and the sensitivity value was comparable to that under verification condition 3 and higher than those under verification conditions 1 and 2. Furthermore, verification condition 4 has the advantage over verification condition 3 of not requiring manual movement of the sample liquid after the pre-reaction. Furthermore, verification condition 4 has less variation in sensitivity values ​​among the three measurement results compared to the other verification conditions 1 to 3. Therefore, there is also the advantage that the measurement results have high accuracy and reproducibility.

[0074] According to the present embodiment described above, a reservoir capable of storing droplets before they flow into a reaction vessel is formed, and a blocking portion capable of blocking and opening one or more vent holes for discharging air from the reaction vessel is formed. As a result, when droplets are dropped into the opening while the vent hole is blocked by the blocking portion, the droplets are stored in the reservoir without flowing into the reaction vessel. While the droplets remain in the reservoir, time for the antigen and liquid-phase antibody to react can be ensured. The blocking portion is then opened, opening the vent hole, and the droplets flow into the reaction vessel with the antigen and liquid-phase antibody sufficiently reacted in advance. In the reaction vessel, the solid-phase antibody reacts with the antigen. This reduces the amount of antigen that reacts with the solid-phase antibody without reacting with the liquid-phase antibody, increasing the possibility of sandwiching the antigen between the liquid-phase antibody and the solid-phase antibody, resulting in high-sensitivity antigen detection.

[0075] Furthermore, since the antigen and liquid-phase antibody can be reacted in advance on the test cartridge simply by closing and opening the closing section, there is no need to separately react the antigen and liquid-phase antibody using a pipette or the like and then transfer the liquid after the reaction. This reduces the number of steps, and improves workability while suppressing variation and deterioration in measurement accuracy due to manual operation. Furthermore, rather than the blocking part directly blocking the air vent, a bank structure is provided around the air vent and the upper surface of the bank structure is blocked, thereby reducing the risk of exposure to sample liquid containing antigens when the blocking part is released.

[0076] The test cartridge 1 according to the present embodiment described above can be applied to relatively low-viscosity liquids such as test solutions containing mucosal epithelium and blood, as well as highly viscous liquids such as sputum and nasal mucus.

[0077] The term "processor" used in the above description refers to a circuit such as a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), or a programmable logic device (e.g., a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), or a field programmable gate array (FPGA)). When the processor is a CPU, for example, the processor realizes its function by reading and executing a program stored in a memory circuit. On the other hand, when the processor is an ASIC, for example, the program is not stored in a memory circuit, but the function is directly incorporated into the processor circuit as a logic circuit. Note that each processor in this embodiment is not limited to being configured as a single circuit, but may be configured as a single processor by combining multiple independent circuits to realize its function. Furthermore, multiple components in the diagram may be integrated into a single processor to realize its function. In other words, efficient and highly accurate testing can be performed. In the above embodiment, the ELISA method using an optical sensor that uses magnetic particles and an optical waveguide has been described as an example, but the measurement method is not limited to this. For example, a fluorescent immunoassay method, a fluorescent polarization immunoassay method, a chemiluminescent immunoassay method, a metal immunoassay method, a spin immunoassay method, etc. may also be used. Furthermore, an immunochromatography method using chromatography may also be used.

[0078] Although several embodiments have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations of embodiments can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0079] 1 test cartridge 2 Sensor chip 3 Analyzer 4 Adhesive part 5 Opening 6 ventilation holes 7 Occlusion 8 Embankment structure 11. Housing 21 Reaction detection area 22 Non-reactive detection area 23a, 23b Grating 51 Storage section 52 Dripping hole 65 Reactor 31 Detection unit 32 Magnetic Field Generator 33 Output Unit 34 Input interface circuit 35 Memory circuit 36 System control circuit 311 Light source 312 Photodetector 331 Display circuit 332 Alarm 333 Printer 361 Light source control function 362 Magnetic Field Control Function 363 Calculation Function 364 Judgment Function 365 Output Control Function

Claims

1. a reaction vessel for containing droplets; a housing including an opening including a reservoir capable of storing the droplets before the droplets flow into the reaction vessel, and one or more vent holes for discharging air from within the reaction vessel; a closing portion formed to be able to close and open the one or more ventilation holes; An inspection cartridge comprising:

2. The test cartridge according to claim 1 , wherein the storage portion is formed on an outer surface side of the housing.

3. The inspection cartridge according to claim 1 , wherein the closing portion opens the one or more air holes when an external force is applied from a state in which the one or more air holes are closed.

4. The inspection cartridge according to claim 1 , wherein the housing has a bank structure on an outer surface of the housing so as to surround the one or more air holes.

5. The test cartridge according to claim 1 , wherein the droplet contains a test substance that is the test target and a detection reagent.

6. The test cartridge according to claim 5 , wherein the reaction chamber includes one or more reaction detection areas that detect the presence or absence of the test substance contained in the droplet by attenuation of light.

7. The test cartridge according to claim 5 , wherein a reagent component contained in the detection reagent undergoes an antigen-antibody reaction with the test substance.

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