Immunological measurement method and immunological measurement device

Abstract

To provide an immunological measurement method and an immunological measurement device that use a magnetic sensor to detect a biomarker with high sensitivity.SOLUTION: An object sample to be measured is introduced into a solution tank in which a linker 12 is fixed to a magnetic sensor 11, and made to react (reaction process). The object sample to be measured has a capture antibody 13, a biomarker as an object 14 to be measured, a detection antibody 15, and a magnetic particle 16. The magnetic particle 16 is coupled to the detection antibody 15. The magnetic particle 16 is put closer to the magnetic sensor 11 (approaching process). After the approaching process is started, the magnetic sensor 11 is used to measure a signal concerned with the object sample to be measured (measuring process).SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an immunoassay method and an immunoassay device. [Background technology]

[0002] Biomarkers are indicators that are widely used to understand the genetic background, physiological state, disease state, etc. of living organisms. One known method for measuring biomarkers is the immunological measurement method. FIG. 1 shows sandwich ELISA, one of the known immunological measurement methods. In a liquid 100, a capture antibody 102 that binds to a biomarker 103, which is the measurement target, is immobilized on the surface of a substrate 101 and reacted with the biomarker 103 in a sample. Next, a detection antibody 104 that binds to the biomarker 103 is reacted. The detection antibody 104 is labeled in advance with an enzyme 105 or the like. Finally, an enzyme reaction occurs by adding a substrate, and the concentration of the biomarker 103 is measured from the absorbance and fluorescent signal intensity.

[0003] A highly sensitive method for measuring a biomarker is required because the concentration of the biomarker itself is low, the amount of sample (body fluid, culture supernatant, etc.) containing the biomarker is small, etc. As a method for increasing sensitivity, for example, Patent Document 1 discloses a method of adding a linker to a capture antibody. This method utilizes the fact that the use of a linker improves the freedom of movement of the capture antibody, thereby increasing the probability of capturing the target biomarker.

[0004] Patent Document 2 discloses a method using a magnetic sensor as a highly sensitive immunological measurement method. The magnetic sensor provided on the substrate shown in FIG. 1 of Patent Document 2 quantifies a biomarker by detecting magnetism of magnetic particles bound to a detection antibody. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2007-531863 [Patent Document 2] JP 2008-128677 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the conventional technology, there is a problem that the detection sensitivity of the biomarker is limited when a magnetic sensor is used.

[0007] A magnetic sensor has the characteristic that the closer the distance to the magnetic particle, the higher the sensitivity. In other words, the greater the distance between the magnetic sensor and the magnetic particle to be measured, the lower the sensitivity of the magnetic sensor. In the conventional immunoassay method using a magnetic sensor, the distance between the magnetic sensor and the magnetic particle becomes longer due to the linker, especially when a linker is added to the capture antibody, making it difficult to improve the detection sensitivity of the biomarker.

[0008] The present invention has been made to solve these problems, and has an object to provide an immunoassay method and an immunoassay device that use a magnetic sensor to detect a biomarker with higher sensitivity. [Means for solving the problem]

[0009] An example of the immunological measurement method according to the present invention includes: a reaction step of introducing a measurement target sample into a solution bath in which a linker is immobilized on a magnetic sensor and reacting the measurement target sample, the measurement target sample comprising a capture antibody, a biomarker as a measurement target, a detection antibody, and magnetic particles, the magnetic particles binding to the detection antibody; a step of bringing the magnetic particles close to the magnetic sensor; a measuring step of measuring a signal of the measurement object sample using a magnetic sensor after the execution of the approaching step is started; has.

[0010] An example of the immunological measurement device according to the present invention is a reaction means for introducing a measurement target sample into a solution bath in which a linker is immobilized on a magnetic sensor, and causing a reaction, the measurement target sample comprising a capture antibody, a biomarker as a measurement target, a detection antibody, and magnetic particles, the magnetic particles binding to the detection antibody; A means for bringing the magnetic particles closer to the magnetic sensor; a measuring means for measuring a signal of the measurement object sample using a magnetic sensor after the operation of the approaching means is started; has. Effect of the Invention

[0011] According to the immunoassay method and immunoassay device of the present invention, a biomarker can be detected with higher sensitivity using a magnetic sensor. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 shows an example of a conventional immunological measurement method. [Diagram 2] FIG. 1 is a diagram showing an outline of the configuration of an immunological measurement device according to Example 1. [Diagram 3] 1 is a process flowchart showing a part of the immunological measurement method according to Example 1. [Figure 4] FIG. 1 is a diagram showing an outline of an immunological measurement method according to Example 1. [Diagram 5] 4 is a detailed flowchart of step S103 in FIG. 3 according to the first embodiment. [Figure 6] FIG. 1 is a diagram for explaining control of the flow direction of a reaction solution. [Figure 7] FIG. 4 is a diagram showing an example of a measurement result according to the first embodiment. [Figure 8] FIG. 8 shows the results of confirming whether the improvement in magnetic signal strength in FIG. 7 is due to the effect of blowing air. [Figure 9] FIG. 13 is a diagram showing the results of confirming whether a magnetic signal specific to a target measurement object is detected in Example 1. [Figure 10]FIG. 1 is a diagram showing an outline of the configuration of an immunological measurement device according to Example 2. [Figure 11] FIG. 1 is a diagram showing an outline of an immunological measurement method according to Example 2. [Figure 12] 4 is a detailed flowchart of step S103 in FIG. 3 according to the second embodiment. [Figure 13] FIG. 11 is a diagram showing an example of a measurement result according to the second embodiment. [Figure 14] FIG. 11 is a diagram showing the results of confirming whether a magnetic signal specific to the target measurement object is detected by Example 2. [Figure 15] FIG. 1 is a schematic diagram showing a modified example of the immunological measurement method according to Example 1 or 2. [Figure 16] FIG. 13 is a diagram showing an outline of the configuration of an immunological measurement device according to Example 3. [Figure 17] 4 is a detailed flowchart of step S103 in FIG. 3 according to the third embodiment. [Figure 18] 13 is a diagram showing an example of the results when magnetic signal detection according to the third embodiment is measured over time. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0014] [Example 1] 2 is a diagram showing an outline of the configuration of the immunological measurement device according to Example 1. The immunological measurement device includes a magnetic measurement device 1, a control unit 2, a computer 3 (e.g., a PC, etc.), and a flow control mechanism 4 (a mechanism for controlling the direction of flow in a solution).

[0015] Fig. 3 is a process flow chart showing a part of the immunoassay method according to Example 1, and Fig. 4 shows an outline of the immunoassay method according to Example 1. The immunoassay device performs this method to carry out immunoassay.

[0016] As shown in Fig. 3, before starting a measurement operation by the magnetic measurement device 1, a magnetic sensor 11 (Fig. 4) is set in the magnetic measurement device 1. A capture antibody 13 that binds to the object to be measured is immobilized on the magnetic sensor 11. A linker 12 is attached to the capture antibody 13 in advance, and the capture antibody 13 is immobilized on the magnetic sensor 11 (for example, on the substrate surface of the magnetic sensor 11) via the linker 12.

[0017] The magnetic sensor 11 is a device that generates a signal (e.g., an electrical signal) in response to magnetic particles in close proximity to the sensor. The magnetic sensor 11 includes, but is not limited to, giant magnetoresistance (GMR) devices. GMR devices include, but are not limited to, spin valve detectors and magnetic tunnel junction (MTJ) detectors.

[0018] 4, the linker 12 binds the capture antibody 13 so that the distance from the magnetic sensor 11 is variable. The linker 12 can be, for example, a chemical substance (e.g., polyethylene glycol (PEG) or lysine), a nucleotide (e.g., DNA or RNA), or the like.

[0019] In this state, the immunological measurement method is started from step S100 onwards in Fig. 3. First, in steps S100 to S102 (reaction step), the magnetic measurement device 1 introduces a measurement target sample into a solution bath and causes a reaction. That is, the magnetic measurement device 1 functions as a reaction means.

[0020] As described above, the linker 12 is immobilized on the magnetic sensor 11 in the solution tank. The measurement target sample includes a capture antibody 13, a measurement target 14 (biomarker), a detection antibody 15, and magnetic particles 16.

[0021] First, in step S100, the object to be measured 14 from the object to be measured sample is added to a solution bath. The capture antibody 13 captures the object to be measured 14. After the addition, the solution may be stirred in order to improve the capture rate of the object to be measured 14 by the capture antibody 13. Any existing stirring method may be used, such as horizontal stirring, vertical stirring, rotational stirring, air blowing stirring, ultrasonic stirring, etc.

[0022] Subsequently, in step S101, the detection antibody 15 is added, and the detection antibody 15 is reacted with the measurement target 14. After the addition of the detection antibody 15, the solution may be stirred to improve the reaction efficiency. The stirring method may be any existing method such as horizontal stirring, vertical stirring, rotational stirring, air blowing stirring, ultrasonic stirring, or the like.

[0023] Next, in step S102, magnetic particles 16 are added, and the magnetic particles 16 are reacted with the detection antibody 15. After that, in step S103, processing such as magnetic signal detection is performed. Note that, although step S103 is described after step S102 in FIG. 3, the magnetic signal detection processing may be started before the execution of step S102, and may be performed continuously before and after step S102.

[0024] The magnetic particles 16 may be ferromagnetic or paramagnetic, and may be made of various magnetic materials such as ferrite and alnico. The magnetic particles 16 are configured to bind to the detection antibody 15, and the measurement target sample may include a binding element that binds the detection antibody 15 and the magnetic particles 16. As the binding element, for example, the detection antibody 15 and the magnetic particles 16 may be previously labeled using an existing method such as biotin-(strept)avidin or biotin-anti-biotin antibody. In the example of FIG. 4, biotin 18 and anti-biotin antibody 19 are used.

[0025] Fig. 5 shows a detailed flowchart of step S103 in Fig. 3 according to the first embodiment. In the first embodiment, step S103 includes steps S103a to S103c.

[0026] After the magnetic particles 16 are added in step S102 of FIG. 3, in step S103a, the flow control mechanism 4 (FIG. 2) operates under the control of the control unit 2 to start blowing air.

[0027] Step S103a is a step (approaching step) of bringing the magnetic particles 16 closer to the magnetic sensor 11. Here, the control unit 2 and the flow control mechanism 4 function as an approaching means. In this embodiment, step S103a includes a step of controlling the direction of the flow of the reaction solution (i.e., the solution in the solution tank during or after the reaction), and in particular includes a step of blowing air onto the liquid surface of the reaction solution.

[0028] The airflow generated by blowing air comes into contact with the surface of the reaction solution as shown in Fig. 6(a), thereby causing the reaction solution to flow in the same direction as the airflow. The direction of the airflow may be perpendicular to the liquid surface, and even in this case, the reaction solution can be caused to flow by the air that collides with the liquid surface and then flows parallel to the liquid surface. Also, as shown in Fig. 6(b), a flow (solution flow) may be generated directly within the reaction solution. For example, this may be done by stirring the reaction solution (more specifically, by rotating and stirring the reaction solution, etc.).

[0029] After the execution of step S103a is started (for example, while step S103a is being executed), step S103b is executed. Step S103b is a process (measurement process) of measuring a signal for the measurement object sample using magnetic sensor 11, whereby a magnetic signal is detected and measurement object 14 is detected. That is, magnetic sensor 11 functions as a measurement means, and measures a signal for measurement object 14 after operation of approach means (control unit 2 and flow control mechanism 4) is started.

[0030] It should be noted that the execution of step S103b does not have to start after the execution of step S103a has started, and the execution of step S103b may start beforehand (in which case, after the execution of step S103a has started, the execution of step S103b will continue until at least the time required for measurement has elapsed).

[0031] After the execution of step S103b starts, step S103c is executed, and the computer 3 stores the magnetic signal and displays information indicating the detection result on the screen. When the air blowing starts, the complex 17 (linker-capture antibody-target object-detection antibody-magnetic particle complex) shown in Fig. 4 changes from the state of Fig. 4(a) to the state of Fig. 4(b), and the magnetic particles 16 come closer to the magnetic sensor 11. Therefore, the measured object 14 can be detected with higher sensitivity using the magnetic sensor 11.

[0032] Fig. 7 shows an example of the measurement results in Example 1. The magnetic signal strength detected in a stationary state without air blowing (Fig. 4(a)) was compared with that detected in a stationary state with air blowing (Fig. 4(b)). As a result, it was confirmed that the magnetic signal strength was improved by about 5 times when air was blown compared to when the device was stationary.

[0033] Figure 8 shows the results of checking whether the improvement in magnetic signal strength in Figure 7 is due to the effect of blowing air. When blowing air and the magnetic signal strength reaches a plateau (around 0 to 5 minutes), if the air blowing is stopped and the device is left to stand (around 5 to 10 minutes), the signal strength decreases. It was found that if air blowing is then started again (around 10 to 20 minutes), the signal strength returns to a strong state. This confirmed the effect of blowing air, which brings magnetic particles closer to the magnetic sensor and improves signal strength.

[0034] Here, many floating magnetic particles exist in the reaction solution shown in Figure 4 without reacting with the detection antibody. Therefore, in principle, it is conceivable that the floating magnetic particles may also approach the magnetic sensor due to the air blowing, resulting in the measurement of a non-specific magnetic signal.

[0035] 9 shows the results of confirming whether a magnetic signal specific to the target measurement target is detected by Example 1. As a result of measuring three types of measurement target samples with different concentrations of the measurement target, it was confirmed that the magnetic signal strength correlates with the concentration of the measurement target, and that specificity is ensured even when air is blown.

[0036] In this way, according to the first embodiment, by controlling the flow direction of the reaction solution, the measurement target 14 can be brought closer to the magnetic sensor 11, enabling detection with higher sensitivity.

[0037] In particular, since the linker 12 binds the capture antibody 13 in such a way that the distance from the magnetic sensor 11 is variable, the object to be measured 14 can be easily brought close to the magnetic sensor 11 .

[0038] Furthermore, the reaction step includes a step (step S101) of reacting the detection antibody 15 with the measurement object 14 and a step (step S102) of reacting the magnetic particles 16 with the detection antibody 15, so that the magnetic particles 16 can be more reliably bound to the measurement object 14. In particular, since a binding element (e.g., biotin 18 and antibiotin antibody 19) that binds the detection antibody 15 and the magnetic particles 16 is used, the magnetic particles 16 can be more reliably bound to the detection antibody 15.

[0039] Furthermore, when the flow direction of the reaction solution is controlled by blowing air, the flow control mechanism 4 can simplify the configuration inside the solution tank, and when the flow direction of the reaction solution is controlled by stirring, the flow can be controlled more efficiently.

[0040] [Example 2] 10 is a diagram showing an outline of the configuration of an immunological measurement device according to Example 2. The immunological measurement device includes a magnetic measurement device 21, a control unit 22, a computer 23 (e.g., a PC), a solution removal mechanism 24, and a cleaning mechanism 25.

[0041] Fig. 11 shows an outline of an immunological measurement method according to Example 2. The basic process flow chart is the same as that in Fig. 3, and the magnetic measurement device 21 functions as a reaction means. Fig. 12 shows a detailed flow chart in Example 2 for step S103 in Fig. 3. In Example 2, step S103 includes steps S103d to S103i.

[0042] 3, after the magnetic particles 16 are added in step S102, detection of a magnetic signal by the magnetic measurement device 21 is started in step S103d. At that time, the solution may be stirred after the addition of the magnetic particles in order to improve the reaction efficiency between the detection antibody 15 and the magnetic particles 16. As the stirring method, any existing method such as horizontal stirring, vertical stirring, rotational stirring, air blowing stirring, ultrasonic stirring, etc. may be used.

[0043] After the start of step S103d, the process proceeds to step S103e, where the magnetic signal is stored and displayed on the PC screen, and then proceeds to step S103f. In step S103f, it is determined whether or not the reaction of the magnetic particles 16 is to be terminated. For the determination, a reaction time may be determined in advance for each type of measurement object, or a threshold value may be determined for the magnetic signal intensity. That is, the reaction may be terminated when the reaction time reaches or exceeds a predetermined threshold, or when the magnetic signal intensity reaches or exceeds a predetermined threshold.

[0044] If the reaction is not to be terminated, the process returns to step S103d, and detection of the magnetic signal continues. If the reaction is to be terminated, in step S103g, the solution removal mechanism 24 (FIG. 10) operates under the control of the control unit 22 to remove the reaction solution. For example, the entire amount of the reaction solution is aspirated and removed. Step S103g is a step of bringing the magnetic particles 16 closer to the magnetic sensor 11 (approaching step). Here, the control unit 22 and the solution removal mechanism 24 function as an approaching means.

[0045] In step S103g, after removing the reaction solution, the washing mechanism 25 washes the magnetic sensor 11 (more specifically, its surface), and the solution removal mechanism 24 may again aspirate and remove the entire amount of washing solution. By washing, it is possible to remove unreacted magnetic particles 16. In this case, the washing mechanism 25 also functions as an approaching means. The washing solution may be sterilized water or a physiological saline solution such as PBS.

[0046] After the solution is removed, the magnetic signal is measured in step S103h. When the solution is removed, the complex 17 shown in Fig. 11 changes from the state shown in Fig. 11(a) to the state shown in Fig. 11(b), and the magnetic particles 16 come closer to the magnetic sensor 11. Therefore, the object to be measured 14 can be detected with higher sensitivity using the magnetic sensor 11.

[0047] After step S103h, step S103i is executed, in which the computer 3 stores the magnetic signal and displays information indicating the detection result on the screen.

[0048] Fig. 13 shows an example of the measurement results in Example 2. In this example, polyethylene glycol (PEG) was used for the linker 12 in Fig. 11. In this experiment, PEG with a molecular weight of 1K and PEG with a molecular weight of 10K were used for the linker 12, and a comparison was made as to the magnetic signal intensity for the same concentration of the substance to be measured. Since the molecular weights differ by about 10 times, the lengths of the linkers 12 also differ by about 10 times.

[0049] FIG. 13(a) shows the magnetic signal intensity before the solution was removed (FIG. 11(a)), and FIG. 13(b) shows the magnetic signal intensity after the solution was removed and washed, and the washing solution was also completely removed (FIG. 11(b)). From the results, it was confirmed that the magnetic signal intensity was stronger when the linker was short (PEG1K) compared to when the linker was long (PEG10K) before the solution was removed (a), and therefore the magnetic signal intensity was stronger when the magnetic particles were closer to the magnetic sensor. Furthermore, as shown in FIG. 13(b) after the solution was removed, the signal intensity was stronger when the linker was long (PEG10K) compared to when the linker was short (PEG1K), and therefore it was confirmed that the linker with a longer linker could capture more of the substance to be measured, and that removing the solution brought the magnetic particles closer to the magnetic sensor, allowing a stronger magnetic signal intensity to be measured.

[0050] 14 shows the results of confirming whether a magnetic signal specific to the target analyte is detected by Example 2. In this example, PEG10K was used as the linker. As a result of measuring three types of analyte samples with different concentrations of the analyte, it was confirmed that the magnetic signal intensity correlates with the concentration of the analyte, and that specificity is ensured even when the solution is removed.

[0051] In this way, according to the second embodiment, by removing the reaction solution, the measurement target 14 can be brought closer to the magnetic sensor 11, and detection can be performed with higher sensitivity.

[0052] FIG. 15 shows an outline of a modified example of the immunoassay method according to Example 1 or Example 2. The basic process flow chart is the same as that shown in FIG. 3, and the magnetic measuring device 21 functions as a reaction means. As shown in FIG. 15, if the difference between the magnetic signal intensities of (b) and (a) is taken as a pure signal from the magnetic signal intensity obtained by quickly repeating a state (a) in which the magnetic nanoparticles are separated from the sensor and a state (b) in which the magnetic nanoparticles are present near the sensor, the magnetic signal intensity can be obtained with less error due to drift and without the need to use a reference sensor such as a blank (or reference) required for zeroing. In other words, it can be used for automatic zeroing adjustment and zero drift detection.

[0053] [Example 3] Fig. 16 is a diagram showing an outline of the configuration of an immunological measurement device according to Example 3. The immunological measurement device includes a magnetic measurement device 31, a control unit 32, a computer 33 (e.g., a PC), a blower mechanism 34, and a liquid level detection mechanism 35. The basic processing flowchart is the same as that in Fig. 3, and the magnetic measurement device 31 functions as a reaction means.

[0054] Fig. 17 shows a flowchart of the step S103 in Fig. 3 according to the third embodiment. In the third embodiment, the step S103 includes steps S103j to S103n.

[0055] 3, after the magnetic particles 16 are added, in step S102, the air blowing mechanism 34 operates under the control of the control unit 32 to bring the magnetic particles 16 closer to the magnetic sensor 11 in step S103j. Step S103j is a step of bringing the magnetic particles 16 closer to the magnetic sensor 11 (bringing step). Here, the control unit 32 and the air blowing mechanism 34 function as a bringing means.

[0056] In this embodiment, it is possible to blow air or stir the liquid, as in the embodiment 1. Therefore, it is possible to detect the measurement target 14 with higher sensitivity using the magnetic sensor.

[0057] The air blowing mechanism 34 blows air, for example, in a direction perpendicular to the surface of the solution. In this embodiment, the evaporation of the solution is promoted by the air blowing mechanism 34 in step S103j. As the solution evaporates, the volume of the solution decreases, and the magnetic particles 16 are brought even closer to the magnetic sensor 11. Thus, in this embodiment, step S103j (bringing closer step) includes a step of promoting the evaporation of the reaction solution.

[0058] The step of promoting the evaporation of the reaction solution is not limited to the blowing of air as in this embodiment. For example, it may be accompanied by heating or chemical treatment. For example, if the blowing of air, heating or chemical treatment is performed in a state where the solution tank is not sealed, the evaporation may be promoted. On the other hand, even if the blowing of air is performed, the evaporation may not be promoted if the solution tank is sealed.

[0059] After the execution of step S103j is started, detection of the magnetic signal is started in step S103k. After the execution of step S103k is started, step S103l is executed, and the magnetic signal is stored in the computer 33 and displayed on the screen.

[0060] In step S103m, it is determined whether or not to terminate the reaction. For example, this determination can be made based on whether or not there is solution remaining in the solution tank using the liquid level detection mechanism 35 (FIG. 16). If it is determined that there is solution remaining, the process returns to step S103j, and steps S103j and S103k are continued. If it is determined that there is no solution remaining, the process proceeds to step S103n, and the reaction and magnetic signal detection are terminated.

[0061] 18 shows an example of the results when magnetic signal detection was measured over time according to Example 3. Since the magnetic signal intensity was stronger when air was blown with evaporation promotion than when air was not blown with evaporation promotion, it was confirmed that blowing air with evaporation promotion enables the measurement of the object to be measured more quickly.

[0062] In this way, according to the third embodiment, by promoting the evaporation of the reaction solution, the measurement target 14 can be brought closer to the magnetic sensor 11, and detection can be performed with higher sensitivity. [Industrial Applicability]

[0063] The immunological measurement devices according to Examples 1 to 3 realize high-sensitivity measurement, and therefore can contribute to the measurement of a measurement target (biomarker) having a low concentration. In addition, since high-sensitivity measurement is realized, it is possible to detect a measurement target contained in a very small amount of a sample, and it is possible to measure even a sample that is difficult to collect. In addition, it can contribute to reducing invasiveness to a living organism. In addition, since high-sensitivity measurement is realized, it can also contribute to shortening TAT (turnaround time). [Explanation of symbols]

[0064] 1...Magnetic measurement device 2...Control section 3. Computer 4. Flow control mechanism 11...Magnetic sensor 12. Linker 13…Capture antibody 14...Measurement object 15. Detection antibody 16...Magnetic particles 17…Complex 18. Biotin 19. Antibiotin antibody 21...Magnetic measuring device 22...Control section 23. Computer 24…Solution removal mechanism 25…Cleaning mechanism 31...Magnetic measuring device 32...Control section 33…Computer 34...Blower mechanism 35...Liquid level detection mechanism

Claims

1. a reaction step of introducing a measurement target sample into a solution bath in which a linker is immobilized on a magnetic sensor and reacting the measurement target sample, the measurement target sample comprising a capture antibody, a biomarker as a measurement target, a detection antibody, and magnetic particles, the magnetic particles binding to the detection antibody; a step of bringing the magnetic particles close to the magnetic sensor; a measuring step of measuring a signal of the measurement object sample using a magnetic sensor after the execution of the approaching step is started; The immunological measurement method comprising the steps of:

2. 2. The immunoassay method according to claim 1, wherein the approaching step includes a step of controlling a direction of a flow of the reaction solution.

3. 2. The immunoassay method according to claim 1, wherein the approaching step includes a step of removing the reaction solution.

4. 2. The immunoassay method according to claim 1, wherein the approaching step includes a step of promoting evaporation of the reaction solution.

5. The immunoassay method according to claim 1, The approaching step includes: Controlling the direction of flow of the reaction solution; promoting evaporation of the reaction solution; The immunological measurement method comprising the steps of:

6. The immunoassay method according to claim 1 , wherein the linker binds the capture antibody to the magnetic sensor such that the distance to the magnetic sensor is variable.

7. The immunoassay method according to claim 1, The reaction step comprises: A step of reacting a detection antibody with the object to be measured; reacting the magnetic particles with the detection antibody; The immunological measurement method comprising the steps of:

8. 2. The immunoassay method according to claim 1, wherein the measurement sample further comprises a binding element that binds the detection antibody and the magnetic particles.

9. 3. The immunoassay method according to claim 2, wherein the step of controlling the direction of the flow of the reaction solution comprises the step of blowing air onto a liquid surface of the reaction solution.

10. 3. The immunoassay method according to claim 2, wherein the step of controlling the direction of the flow of the reaction solution comprises the step of stirring the reaction solution.

11. a reaction means for introducing a measurement target sample into a solution bath in which a linker is immobilized on a magnetic sensor, and causing a reaction, the measurement target sample comprising a capture antibody, a biomarker as a measurement target, a detection antibody, and magnetic particles, the magnetic particles binding to the detection antibody; A means for bringing the magnetic particles closer to the magnetic sensor; a measuring means for measuring a signal of the measurement object sample using a magnetic sensor after the operation of the approaching means is started; An immunoassay device comprising:

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