JP3722600B2 - Immunoassay device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an immunoassay device that uses an antigen-antibody reaction, and more particularly to an immunoassay device that measures a test item that requires high accuracy such as an infectious disease item.
[0002]
[Prior art]
An immunoassay is usually performed by performing an immunoassay based on an antigen-antibody reaction on a test item related to a tumor marker or infectious disease, which is a trace protein in a biological component such as blood, and a specimen obtained from a reaction specific to the antigen-antibody reaction. Perform an immunochemical assessment. As the immunological test method, a neferometer method, a radioimmunoassay method (RIA), an enzyme immunoassay method (EIA), and an immunoagglutination assay method (CIA) are known.
Since biological components include various components and have large individual differences, so-called non-specific reactions other than the original specific antigen-antibody reaction may occur. In order to suppress this non-specific reaction, the reaction system is adjusted by various methods. However, since biological components are rich in diversity, the non-specific reaction cannot be completely eliminated.
[0003]
[Problems to be solved by the invention]
Since a nonspecific reaction in an immunoassay cannot be completely suppressed, it is preferable to confirm whether or not the measurement result is an original antigen-antibody reaction when the measurement result of the immunoassay is positive. For this reason, an initial immunoassay is performed on a sample that has undergone an antigen-antibody reaction by adding an antibody corresponding to the antigen to be measured or an antibody or a solution containing the antigen (absorbing liquid for confirmation) to the specimen. A method for confirming whether a measurement result is a result of an original antigen-antibody reaction is known.
However, this method is not used so much because it takes time and labor to separate the sample again and react with the absorption solution for confirmation.
[0004]
One of the objects of the present invention is to provide an immunoassay apparatus capable of performing an absorption test together with a normal test quickly, easily and with high accuracy.
[0005]
[Means for Solving the Problems]
According to this invention, the sample storage unit that stores the sample to be measured, the reagent storage unit that stores the reagent of the measurement item, the reaction unit that performs the antigen-antibody reaction of the sample and the reagent, and the sample storage unit In the immunoassay device comprising a dispensed sample and a dispensing unit for dispensing the reagent accommodated in the reagent accommodating unit, the reagent accommodating unit contains an absorption liquid for confirmation, and the dispensing When the measurement result of the antigen-antibody reaction between the sample and the reagent dispensed by the unit to the reaction unit is within a predetermined range, the sample, the reagent, and the absorption liquid for confirmation are dispensed to the reaction unit by the dispensing unit. , to perform the absorption test, the measurement results of the absorption test compared with a preset threshold, comprises a control unit determines specific reaction or based on the comparison result immunization Constant apparatus is provided.
[0006]
That is, according to the present invention, when the first measurement result is positive, the specimen is re-sorted from the specimen storage unit by the absorption test supplement means, and the specimen and the absorption liquid for confirmation are supplied to the reaction unit. Since the absorption test is performed, the absorption test for confirming whether or not the first measurement result is a reaction specific to the antigen-antibody reaction can be automatically performed. Therefore, it is possible to respond quickly even when confirmation is required, and the correctness / incorrectness determination of the first measurement result, that is, the result of the normal inspection can be performed reliably and promptly.
[0007]
The sample storage unit in the present invention refers to a container for storing a sample such as serum or urine, for example, a unit that can store a plurality of sample cups or blood collection tubes, and has a function of adding or interrupting a sample stored in the container even during measurement. Is preferred.
[0008]
The reaction unit in the present invention is a mechanism unit for controlling an immune reaction, and includes a constant temperature unit that keeps the temperature constant and a shaking unit that applies constant shaking. In order to perform a plurality of inspections at high speed, it is preferable that a large number of reaction vessels are provided, and that the reaction vessels after the measurement have a function of being reused by washing or replaced with unused reaction vessels.
[0009]
The absorption liquid for confirmation in this invention refers to a solution containing a sufficient amount of antibody or antigen corresponding to the antigen or antibody of the analyte to be measured. For example, when measuring an HBs antigen, it refers to a liquid that sufficiently contains an HBs antibody, and when measuring an HBs antibody, it refers to a liquid that sufficiently contains an HBs antigen.
[0010]
The absorption test in the present invention is the absorption value and the control value obtained by carrying out normal measurement after the antigen-antibody reaction with the specimen for the absorption liquid for confirmation and its control liquid (solvent of the liquid for confirmation), respectively. This is a method for determining the absorption rate from the sample and confirming whether or not the measurement result of the sample is due to the original specific antigen-antibody reaction. This method is sometimes called a confirmation test or a neutralization test.
[0011]
In this invention, “when the measurement result of the sample is within the predetermined range” is preferably set to a range from a cut-off value to a weakly positive value, but in some cases includes all positive and values below the cut-off Can be set arbitrarily. However, it is meaningless in the nature of this test to include a value at which no response below the minimum sensitivity is observed.
[0012]
In the dispensing unit according to the present invention, the sample stored in the sample storage unit is collected, the sample moved by relative movement to the reaction unit is dispensed, the absorption liquid for confirmation is collected, and the reaction unit is separated. The pipette which can dispense the absorption liquid for confirmation picked up by relative movement is mentioned. This pipette preferably has a cleaning mechanism for supplying and discharging the cleaning liquid to clean the inside and outside of the pipette.
[0013]
Based on the measurement result of the absorption test, it is informed that the first measurement result should be confirmed by further providing a warning display means for displaying a warning when the comparison result is a non-specific reaction. Can be easily distinguished from other specimens.
Examples of the warning display means include an integrated display means and notification means for reporting sign lighting, blinking, buzzer, and beep sound on a display screen such as an LCD.
[0014]
By providing correction display means for correcting and displaying the measurement result of the specimen based on the measurement result of the absorption test, when the first measurement result is overturned by the absorption test, the first measurement result and the result of the absorption test are displayed. It is possible to avoid confusion due to both of them remaining.
As the correction display means, for example, a display screen such as an LCD can be cited, and the measurement result replacement operation on this display screen is automatically performed. It is possible to display the result of the measurement to the operator more clearly and distinctly from other specimens for which normal test values are obtained. Examples of the warning means include lighting of a sign on the display screen, blinking, buzzer, and notification of a beep sound.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below based on the embodiment shown in the drawings. However, this does not limit the present invention.
FIG. 1 shows a schematic configuration of an immunoassay device 10 according to one embodiment of the present invention. The immunoassay apparatus 10 includes a detection unit 1, a reaction unit 2, a dispensing unit 3 that dispenses a sample, a reaction reagent, an absorption solution for confirmation, and the like (also serves as a means for supplying a sample solution, a reaction reagent, and a confirmation solution) And a reagent storage unit 4 for installing reagents and a sample storage unit 5 for installing samples.
[0016]
The detection unit 1 includes a flow cell 11, an optical system 12 that measures a reaction sample passing through the flow cell 11, and a chamber 13 for introducing the reaction sample dispensed from the reaction unit 2 into the flow cell 11. The optical system 12 includes a photoelectric conversion unit 15, an AD conversion unit 16, an analysis counting unit 17, a concentration conversion unit 18, and a display unit 19 having a laser light source 14 and a light receiving element facing each other with the flow cell 11 therebetween. The display unit 19 serving as a warning display unit and a correction display unit includes an LCD, a printing unit, and a beep sound source. The flow cell 11 and the chamber 13 are connected by a sheath liquid supply pipe 21, and a sheath liquid supply port portion 22, a discharge port portion 23, a syringe pump 24, and a plurality of control valves 25 are connected to the pipe 21.
[0017]
The reaction unit 2 includes a reaction plate 26 in which a plurality of reaction vessels are arranged, a reaction tray 27 on which the reaction plate 26 can be placed, and a tray transport unit 28 that can carry the reaction plate 26 into the reaction tray 27. The reaction tray 27 includes a constant temperature heater (not shown) for incubating the sample accommodated in the reaction plate 26 carried in the upper part, and a stirring unit (not shown) for further reaction and shaking and stirring.
[0018]
The dispensing unit 3 includes a reaction plate catcher 30, a pipette 31, and an XY moving unit 32 that moves the pipette 31 in the XY axis direction on the table. The reaction plate catcher 30 and the pipette 31 include a Z moving means 37 that can move in the Z-axis direction, and are attached to the XY moving means 32 via the Z moving means 37. One end of the pipette 31 is connected to a dispensing syringe 34 via a flexible tube 33, and a sheath liquid supply port portion 36 having a control valve 35 is branched into the tube 33. When the dispensing syringe 34 is driven, the sheath liquid supplied into the tube 33 from the sheath liquid supply port 35 enables the sample liquid to be dispensed and becomes a cleaning liquid for the tube 33 and the pipette 31.
[0019]
The reagent storage unit 4 stores reagents such as a buffer solution, a latex reagent (reaction reagent), a confirmation absorbing solution, a confirmation control solution, and a sample diluent so that the pipette 31 can dispense them. And is provided with a cooling means (not shown) for cooling these reagents. The sample storage unit 5 is configured to store a plurality of sample cups 51a that are samples containers and a sample rack for blood collection tubes, and can be moved horizontally by a transport rack 52. These can be added or interrupted in units of containers or sample racks during measurement.
[0020]
The input / output unit of each mechanism described above is connected to a control unit described later. FIG. 2 is a control block configuration diagram of the immunoassay device 10.
The immunoassay device 10 includes a control unit 6 including a microcomputer having a CPU, ROM, RAM, timer, counter, and the like. The control unit 6 includes a key input unit 61, a display unit 19, a syringe pump 24, a control valve 25, a tray transport unit 28, an XY moving unit 32, a dispensing syringe 34, a control valve 35, a Z moving unit 37, Each input / output unit of the transport rack 52 is connected.
[0021]
An example of the operation of the immunoassay device 10 will be described based on the flowchart of FIG. The following operations are controlled by commands from the control unit 6.
After the initial setting is made in step S1, it is determined whether or not an order is input in step S2. If it is determined that the inspection order has been input, the process proceeds to step S3. In step S <b> 3, the pipette 31 is moved and the dispensing syringe 34 is driven to dispense 10 μl of the specimen from the specimen sample cup 51 a of the sampler 51 to the reaction tank 26 a of the reaction plate 26.
[0022]
Next, in step S4, the pipette 31 is moved and the dispensing syringe 34 is driven to dispense 80 μl of the buffer solution in the reagent storage unit 4 into the reaction tank 26a in which the specimen is stored.
Next, in step S5, the pipette 31 is moved and the dispensing syringe 34 is driven to add 10 μl of the latex reagent in the reagent storage unit 4 to the reaction vessel 26a. The addition of the latex reagent initiates the antigen-antibody reaction. Note that the specimen to which the above-described reagent or the like is added is hereinafter referred to as a reaction sample.
[0023]
Next, in step S6, the reaction plate 26 containing the sample and reagent is incubated for 15 minutes. After this incubation, the process proceeds to step S7 where the pipette 31 is moved and the dispensing syringe 34 is driven to dispense 19 μl of the reaction sample in the reaction vessel 26a into the chamber 13. The chamber 13 is prefilled with 950 μl of sheath liquid by a syringe pump 24, and the reaction sample is diluted 51 times by this sheath liquid. By diluting the reaction sample, the antigen-antibody reaction is stopped and the particle concentration is adjusted to an appropriate value for measurement.
[0024]
Next, the sample diluted for this measurement is pumped to the flow cell 11 by the syringe pump 24, and the aggregated latex particles passing through the flow cell 11 are measured by the optical system 12. A value obtained by converting the measured aggregation rate (P / T) is displayed on the display unit 19 (steps S8 to S9).
To describe this step in detail, the reaction between the antibody-bound latex and the antigen in the specimen forms an agglomerated latex according to the amount of antigen, and when these latex particles are arranged in a row and passed through the flow cell, laser light is emitted. Irradiate latex particles to produce forward scattered light. This forward scattered light is photoelectrically converted and captured as a pulse, and after obtaining a particle size distribution reflecting the size and number of latex particles, P / (P + M) is calculated from the number P of aggregated latex particles and the number M of unaggregated latex particles. to obtain the antigen concentration in the test body from the previously obtained calibration curve.
[0025]
Next, in step S10, it is determined whether or not the measurement value based on the aggregation rate is within a predetermined range. That is, a positive or negative determination is made by comparing the obtained antigen concentration with a predetermined antigen concentration range set in advance. If it is determined that the measured value is within the predetermined range, an absorption test after step S11 is performed. In addition, this absorption test is a control (step S11-18) for obtaining an absorption measurement value of an absorption sample obtained by adding a confirmation absorption liquid to a sample that has been positively determined, and a control obtained by adding a confirmation control liquid to the same sample. The process of obtaining the control measurement value for the sample (steps S19 to S26) is performed in parallel, and the absorption rate as the threshold value for confirmation inspection is calculated from these. Note that the step of using the confirmation control solution may be omitted, and only the step of using the confirmation absorbent may be used.
[0026]
First, in step S11, the pipette 31 is moved and the dispensing syringe 34 is driven to dispense 90 μl of the sample of the sampler 51 into the reaction tank 26b of the reaction plate 26 as a confirmation sample.
Next, in step S12, the pipette 31 is moved and the dispensing syringe 34 is driven to dispense 10 μl of the absorption liquid for confirmation in the reagent storage unit 4 into the reaction tank 26b.
Next, in step S13, the confirmation reaction sample stored in the reaction plate 26 is incubated at a reaction temperature of 45 ° C. for a reaction time of about 10 minutes.
[0027]
Furthermore, in step S13, the pipette 31 is driven to dispense 10 μl of the confirmation reaction sample stored in the reaction tank 26b of the reaction plate 26 into another reaction tank 26c. Further, in step S14, the pipette 31 is driven to dispense 80 μl of the buffer solution in the reagent storage unit 4 into the reaction tank 26c in which 10 μl of the confirmation reaction sample is accommodated.
Next, in step S15, the confirmation reaction sample stored in the reaction plate 26 is pre-incubated at a reaction temperature of 45 ° C. for a reaction time of about 1 minute. Thereby, the factor which causes the non-specific reaction contained in the reaction sample is absorbed and buffered.
[0028]
Next, in step S16, the pipette 31 is moved by the XY moving means 32 and the Z moving means 37 and the dispensing syringe 34 is driven, so that 10 μl of the latex reagent in the reagent storage unit 4 is used for confirmation in the reaction tank 26c. Add to reaction sample. The addition of the latex reagent initiates the antigen-antibody reaction. Note that the amount of the confirmation test reagent added to the reaction sample is changed according to the test item.
Next, in step S17, the reaction sample for confirmation stored in the reaction plate 26 is incubated at a reaction temperature of 45 ° C. for a reaction time of about 15 minutes. As a result, all antigens contained in the confirmation reaction sample bind to the antibody by a specific reaction to form an aggregate. After this incubation, the process proceeds to step S18, and the reaction sample for confirmation is measured.
[0029]
In the step of performing the control sample measurement that is performed in parallel with obtaining the absorption value, first, in step S19, the pipette 31 is moved and the dispensing syringe 34 is driven, and 90 μl of the sample of the sampler 51 is transferred to the control sample. Dispense as. In step S <b> 20, the dispensing syringe 34 is driven to dispense 10 μl of the confirmation control solution in the reagent storage unit 4 into the reaction tank 26 d of the reaction plate 26. Next, in step S21, 10 μl of the control sample stored in the reaction tank 26d of the reaction plate 26 is dispensed into another reaction tank 26e. In subsequent steps S22 to S26, the same operation as that for obtaining the absorption value is performed.
[0030]
Next, an absorption value and a control value (U / ml) are calculated in step S27.
The operation of the optical immunity detection unit 1 for obtaining the absorption value and the control value will be described. First, the sheath fluid is pumped to the flow cell 11 by the syringe pump 24, and the latex / antigen aggregate or latex passing through the flow cell 11 is first described. Measure the size of antibody aggregate particles with the optical system 12. In the optical system 12, the measured degree of particle aggregation is converted into a concentration using a calibration curve prepared in advance.
Absorption rate A (%) is calculated from the obtained absorption value and control value. Absorption rate A (%) is calculated | required with the following formula | equation.
[0031]
[Formula 1]
Absorption rate A (%) = (control value−absorption value) / control value × 100
When the experiment using the control solution is omitted, it can be obtained by the following formula using the sample measurement value.
Absorption rate A (%) = (sample measurement value−10 / 9 × absorption value) / sample measurement value × 100
[0032]
Next, the process proceeds to step S28, and the absorption rate A (%) is compared with a preset threshold value. This threshold value is set according to the absorption performance of the absorption liquid for confirmation of each measurement item. For example, in the case of FIG. 4, when the absorption rate A (%) is 70 (%) or more, it is determined that the measurement substance is absorbed and the antibody is considered positive, and when it is less than 30 (%), the measurement substance Is a threshold value that serves as an index for determining that the antibody is not absorbed and can be regarded as antibody-negative.
[0033]
When the absorption rate A (%) is 70 (%) or more in step S28, the process proceeds to step S29, and it is determined that the reaction is a specific reaction in the normal test.
On the other hand, if the absorption rate A (%) is less than 70 (%) in step S28, the process proceeds to step S30, and a normal test value is displayed on the display unit 19 because a nonspecific reaction may have been involved in the normal test. Flashes to warn you. In particular, if it is less than 30 (%), it is assumed that the value of the normal inspection is incorrect, and a warning is given to correct the result of the normal inspection.
[0034]
As described above, in the above-described embodiment, the normal test value indicates a value within a predetermined range, and the sample is immediately re-sorted by the dispensing unit 3 and the confirmation absorbing liquid is supplied to automatically perform the confirmation test. As a result, the presence or absence of a non-specific reaction in the normal test can be confirmed, so that the correctness / incorrectness of the normal test result can be reliably and quickly determined.
[0035]
【The invention's effect】
According to the immunoassay device of the present invention, when the first measurement result is within a predetermined range, the control unit re-sorts the specimen by the dispensing unit, performs the absorption test, and displays the measurement result of the absorption test. Since it is configured to determine whether or not a specific reaction is based on the comparison result compared with a preset threshold value, an absorption test is performed to confirm whether or not the first measurement result is a specific antigen-antibody reaction. It can be automatically performed in parallel with the normal inspection.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an immunoassay device according to one embodiment of the present invention.
FIG. 2 is a control block diagram of the immunoassay device of FIG.
FIG. 3 is a flowchart for explaining the operation of the immunoassay device of FIG. 1;
FIG. 4 is a diagram showing an example of the absorption performance of a confirmation absorbent.
[Explanation of symbols]
First detection unit 2 reaction units 3 dispensing unit 4 a reagent storage unit 10 immunoassay apparatus 31 pipette

Claims (3)

A sample storage unit that stores a sample to be measured, a reagent storage unit that stores a reagent of a measurement item, a reaction unit that performs an antigen-antibody reaction between the sample and the reagent, a sample stored in the sample storage unit, and the reagent In an immunoassay device comprising a dispensing unit for dispensing a reagent stored in a storage unit ,
The reagent storage unit stores an absorption solution for confirmation, and when the measurement result of the antigen-antibody reaction between the specimen and the reagent dispensed to the reaction unit by the dispensing unit is within a predetermined range, the dispensing is performed. The sample is dispensed with the specimen, reagent and absorption liquid for confirmation into the reaction unit, an absorption test is performed, and the measurement result of the absorption test is compared with a preset threshold value. An immunoassay device comprising a control unit for determining whether or not . The immunoassay device according to claim 1, wherein a measurement result of the absorption test is an absorption rate . The immunoassay device according to claim 1 or 2 , further comprising warning display means for displaying a warning when the comparison result is a non-specific reaction .

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