JPH11101803A - Immunoassay apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an immunoassay apparatus by which an absorption test can be executed quickly, easily and with high accuracy together with an ordinary inspection by a method wherein, when the measured result of a sample is within a prescribed range, a sample which has been re-taken in portion and an absorption solution for confirmation are supplied to a reaction plate and the absorption test is executed. SOLUTION: A sample which is diluted, for a measurement, in a chamber 13 is pressure-fed by a syringe pump 24 from a reaction plate 26 in which the sample and a reagent are housed, and the agglomeration rate of agglomerated late particles which are passed through a flow cell 11 is measured by an optical system 12. When a measured value based on the aggregation rate is within a prescribed range, an absorption test is executed. That is to say, a pipette 31 at a dispensing unit 3 is moved, syringe 34 for dispensing is driven, a sample which is re-taken in portion from a sampler 51 and an absorption solution, for confirmation, in a reagent unit 4 are dispensed to the reaction plate 26, and an absorption measured value is obtained. In parallel with this operation, a reference measured value is obtained from a reference sample in which a solution to be confirmed is added to the sample, and an absorption rate as a threshold value for confirmation inspection is computed. Thereby, the absorption test can be executed quickly, easily and with high accuracy together with an ordinary inspection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an immunoassay apparatus utilizing an antigen-antibody reaction, and more particularly, to an immunoassay apparatus for measuring a test item requiring high accuracy, such as an infectious disease item.

[0002]

2. Description of the Related Art In general, an immunological test is performed by performing an immunological test based on an antigen-antibody reaction for a test item related to a tumor marker or an infectious disease, which is a trace protein in a biological component such as blood, and is specific to the antigen-antibody reaction. The immunochemical determination of the sample is performed based on the typical reaction. Immunoassays include nephelometry, radioimmunoassay (RIA), enzyme immunoassay (EI
A) An immunoagglutination assay (CIA) is 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, but the biological components are so diverse that the non-specific reaction cannot be completely eliminated.

[0003]

The non-specific reaction in the immunoassay cannot be completely suppressed. Therefore, if the result of the immunoassay becomes positive, it is determined whether or not this measurement result is due to the original antigen-antibody reaction. It is preferable to confirm that For this reason, a solution containing an antibody or an antigen corresponding to the antigen or antibody to be measured (confirmation absorption solution) is added to the sample, and the same immunoassay is performed on the sample in which the antigen-antibody reaction has occurred, thereby performing an initial immunoassay There is known a method of confirming whether the measurement result is the result of the original antigen-antibody reaction.
However, this method has not been used because the sample has to be collected again and separately reacted with the confirming absorbing solution, which takes time and effort.

An object of the present invention is to provide an immunoassay apparatus capable of performing an absorption test quickly, easily and with high accuracy together with a normal test.

[0005]

According to the present invention, a sample storage unit for storing a sample to be measured, a reagent storage unit for storing a reagent of a measurement item, and an antigen-antibody reaction between the supplied sample and a reagent are provided. In the immunoassay apparatus provided with a reaction unit for controlling the sample, when the measurement result of the sample is within a predetermined range, the sample is re-sorted from the sample storage unit, and the sample and the absorbing solution for confirmation are transferred to the reaction unit. There is provided an immunoassay device comprising an absorption test supplementary means for supplying and performing an absorption test.

That is, according to the present invention, when the first measurement result is positive, the sample is re-sorted from the sample storage unit by the absorption test supplementary means, and the sample and the confirmatory absorption solution are subjected to the reaction. Since it is configured to supply the unit and perform the absorption test, 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, no matter what time the confirmation is required, the response can be promptly made, and the first measurement result, that is, the result of the normal inspection, can be correctly and erroneously determined.

[0007] The sample storage unit in the present invention is:
It refers to a container for storing a sample such as serum or urine, for example, a unit capable of storing a plurality of sample cups or blood collection tubes, and preferably has a function of adding or interrupting the sample placed in the container even during measurement.

The reaction unit according to the present invention is a mechanism for controlling an immune reaction, and includes a constant temperature section for maintaining a constant temperature and a shaking section for applying a constant shaking. In order to perform a plurality of inspections at a high speed, it is preferable to provide a large number of reaction tanks, and to provide a function to reuse the reaction tanks after washing or replace them with unused reaction tanks.

In the present invention, the confirming absorbing solution refers to a solution containing a sufficient amount of the antibody or antigen corresponding to the antigen or antibody of the specimen to be measured. For example, when measuring the HBs antigen, it refers to a solution containing a sufficient amount of the HBs antibody,
When the s antibody is measured, it refers to a solution containing sufficient HBs antigen.

[0010] The absorption test in the present invention refers to an absorption test solution and a control solution (solvent of the test absorption solution), which are each subjected to an antigen-antibody reaction with a sample and then subjected to a normal measurement. And a method of determining the absorption rate from a control value and confirming whether or not the measurement result of the sample is due to an original specific antigen-antibody reaction. This method is sometimes called a confirmation test or a neutralization test.

In the present invention, "when the measurement result of a sample is within a predetermined range" is preferably set to a range from a cutoff value to a weak positive value. It can be set arbitrarily to include a value. 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] The absorption test supplementary means in the present invention includes:
The sample stored in the sample storage unit is dispensed, moved relatively to the reaction unit, dispensed the dispensed sample, the absorptive liquid for confirmation is dispensed, and moved relatively to the reaction unit for confirmation. A pipette capable of dispensing an absorbing solution is included. The pipette preferably has a cleaning mechanism for supplying and discharging a cleaning liquid to clean the inside and outside of the pipette.

[0013] By further providing a warning display means for giving a warning and display based on the measurement result of the absorption test, it is notified that the first measurement result is to be confirmed, and easily distinguished from other samples. can do. The warning display means includes a sign light on a display screen such as an LCD,
An example in which a display means for notifying a blinking, buzzer, or beep sound and a notifying means are integrated is given.

A correction display means for correcting and displaying the measurement result of the sample based on the measurement result of the absorption test is further provided, so that when the first measurement result is reversed by the absorption test, the first measurement result and the absorption test Can be avoided because both of the above results remain. As the correction display means, for example, a display screen such as an LCD can be cited. By automatically performing the operation of replacing the measurement results on this display screen, a non-specific reaction intervenes in the normal test value, thereby causing an error. The result can be displayed to the operator more reliably and clearly distinguished from other samples for which normal test values have been obtained. Examples of the warning means include a sign lighting, blinking or buzzer, and a beep sound on the display screen.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment shown in the drawings. Note that the present invention is not limited to this. FIG. 1 shows a schematic configuration of an immunoassay apparatus 10 according to one embodiment of the present invention. The immunoassay device 10 includes a detection unit 1 and a reaction unit 2
, A dispensing unit 3 for dispensing a sample, a reaction reagent, a confirming absorbing solution, and the like (also serving as a supply unit for a sample liquid, a reaction reagent, and a confirming liquid), and a reagent storage unit 4 for installing reagents
And a sample storage unit 5 for installing a sample.

The detection unit 1 includes a flow cell 11 and an optical system 12 for measuring a reaction sample passing through the flow cell 11.
And a chamber 13 for introducing a reaction sample dispensed from the reaction unit 2 into the flow cell 11. The optical system 12 includes a photoelectric conversion unit 15 having a laser light source 14 and a light receiving element facing each other with the flow cell 11 therebetween, an AD conversion unit 16, an analysis and counting unit 17, a density conversion unit 18, and a display unit 19. The display unit 19 as a warning display unit and a correction display unit has 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 22, a discharge port 23, a syringe pump 24, and a plurality of control valves 25 are connected to the pipe 21.

The reaction unit 2 includes a reaction plate 26 in which a plurality of reaction tanks are arranged, a reaction tray 27 on which the reaction plate 26 can be placed, and a reaction tray 26
And a tray transport unit 28 which can be carried into the tray 7. The reaction tray 27 includes a constant temperature heater (not shown) for incubating the sample stored in the reaction plate 26 carried in the upper portion thereof, and a stirring unit (not shown) for performing reaction, shaking and stirring.

The dispensing unit 3 comprises a reaction plate catcher 30, a pipette 31, and XY moving means 32 for moving the pipette 31 on the table in the XY axis directions. The reaction plate catcher 30 and the pipette 31
A Z-moving means 37 movable in the Z-axis direction is provided, and attached to the XY moving means 32 via the Z-moving means 37. One end of the pipette 31 is connected to a syringe 34 for dispensing via a flexible tube 33, and a sheath liquid supply port 36 having a control valve 35 is branched from the tube 33. When the dispensing syringe 34 is driven, the sheath liquid supplied from the sheath liquid supply port 35 into the tube 33 enables dispensing of the sample liquid, and serves as a washing liquid for the tube 33 and the pipette 31.

The reagent storage unit 4 is provided with respective containers so that the pipette 31 can dispense reagents such as a buffer solution, a latex reagent (reaction reagent), an absorption solution for confirmation, a control solution for confirmation, and a sample diluent. And a cooling means (not shown) for keeping the reagents cool is provided below. The sample storage unit 5 is configured to be able to store a plurality of sample cups 51a as sample containers and sample racks for blood collection tubes, and can be moved horizontally by the transport rack 52. These can be added or interrupted in units of containers or sample racks during measurement.

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 apparatus 10. The immunoassay device 10 has a CP
The control unit 6 includes a microcomputer having a U, a ROM, a RAM, a timer, a counter, and the like. The control unit 6 includes a key input unit 61 (not shown), a display unit 19, a syringe pump 24, a control valve 25, a tray transport unit 28, an XY
Each input / output unit of the moving means 32, the dispensing syringe 34, the control valve 35, the Z moving means 37, and the transport rack 52 is connected.

An example of the operation of the immunoassay apparatus 10 will be described with reference to the flowchart of FIG. The following operation is performed by the control unit 6
Is controlled by the command of After the initial settings are made in step S1, it is determined in step S2 whether an order has been input. If it is determined that the inspection order has been input, the process proceeds to step S3. In step S3, the pipette 31 is moved and the dispensing syringe 34 is driven to dispense 10 μl of the sample from the sample cup 51a for the sampler 51 to the reaction tank 26a of the reaction plate 26.

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 containing the sample. 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 tank 26a. The addition of this latex reagent initiates the antigen-antibody reaction. In addition,
The sample to which the above reagents and the like have been added is hereinafter referred to as a reaction sample.

Next, in step S6, the reaction plate 26 containing the sample and the reagent is incubated for 15 minutes. After this incubation, the process moves to step S7, in which the pipette 31 is moved, and the dispensing syringe 34 is driven to drive the reaction sample 1 in the reaction tank 26a.
Dispense 9 μl into chamber 13. The chamber 13 is previously filled with 950 μl of the sheath liquid by the syringe pump 24, and the reaction sample is diluted 51 times by the sheath liquid. By diluting the reaction sample, the antigen-antibody reaction is stopped and the particle concentration is adjusted to an appropriate particle concentration for measurement.

Next, the sample diluted for the measurement is pumped into 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. The value obtained by converting the measured aggregation rate (P / T) is displayed on the display unit 19 (steps S8 to S9). To explain this step in detail, the reaction between the antibody-bound latex and the antigen in the sample forms an aggregated latex corresponding to the amount of the antigen.When the latex particles are arranged in a line and passed through a flow cell, laser light is emitted. The latex particles are irradiated to produce forward scattered light. This forward scattered light is photoelectrically converted and captured as a pulse to obtain a particle size distribution that reflects the size and number of latex particles.
M) is calculated, and the antigen concentration in the antibody is obtained from the calibration curve obtained in advance.

Next, in step S10, it is determined whether or not the measured 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 you determine that the measurement is within a certain range,
An absorption test after step S11 is performed. In this absorption test, a step of obtaining an absorption measurement value of an absorption sample in which a confirmation absorption liquid was added to a positively determined sample (steps S11 to S18) and a control in which a confirmation control solution was added to the same specimen were performed. The step of obtaining the reference measurement value of the sample (steps S19 to S26) is performed in parallel, and the absorbance as the confirmation inspection threshold is calculated from these. The step of using the control solution for confirmation may be omitted, and only the process of using the absorption solution for confirmation may be performed.

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 confirming absorbent 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. and a reaction time of about 10 minutes.

Further, in step S13, the pipette 31
Is driven to dispense 10 μl of the confirmation reaction sample contained 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 containing 10 μl of the confirmation reaction sample. Next, in step S15, the pre-incubation is performed on the confirmation reaction sample stored in the reaction plate 26 at a reaction temperature of 45 ° C. and a reaction time of about 1 minute. This allows
Factors that cause non-specific reactions contained in the reaction sample are absorbed and
Buffered.

Next, in step S16, the pipette 31 is moved by the XY moving means 32 and the Z moving means 37, and at the same time, the dispensing syringe 34 is driven to transfer 10 μl of the latex reagent in the reagent storage unit 4 to the reaction tank 26c.
Add to the confirmation reaction sample in the above. The addition of this 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 confirmation reaction sample 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 the antigens contained in the confirmation reaction sample are combined with the antibody by a specific reaction to form aggregation. After this incubation, the process proceeds to step S18, where the measurement of the reaction sample for confirmation is performed.

In the step of performing a control sample measurement proceeding in parallel with obtaining the absorption value, first, in step S19, the pipette 31 is moved and the dispensing syringe 34 is driven to transfer 90 μl of the sample of the sampler 51. Dispense as a control sample. In step S20, the dispensing syringe 34 is driven to dispense 10 μl of the control solution for confirmation in the reagent storage unit 4 into the reaction tank 26d of the reaction plate 26. Next, in step S21, the reaction plate 26
Is dispensed into another reaction tank 26e. From step S22 to step S26, the same operation as that for obtaining the above-described absorption value is performed.

Next, in step S27, an absorption value and a control value (U / ml) are calculated. The operation of the optical immunodetection unit 1 for obtaining the absorption value and the control value will be described. First, the sheath liquid 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 passed. The size of the particles of the antibody aggregate is measured by the optical system 12. Optical system 1
In step 2, the measured degree of aggregation of the particles is converted into a concentration using a previously prepared calibration curve. The absorption rate A (%) is calculated from the obtained absorption value and control value. The absorption rate A (%) is obtained by the following equation.

[0031]

## EQU00001 ## Absorbance A (%) = (control value-absorption value) / control value.times.100 When the experiment using the control solution is omitted, it can be obtained by the following formula using the measured value of the sample. Absorption rate A (%) = (measured value of sample−10 / 9 × absorption value) /
Sample measurement value x 100

Next, the flow shifts to step S28, where the absorption rate A
(%) Is compared with a preset threshold value. This threshold value is set according to the absorption performance of the check absorbing liquid of each measurement item. For example, in the case of FIG. 4, the absorption rate A (%) is 70 (%).
In the above cases, it is determined that the test substance has been absorbed and the antibody is considered to be positive. When it is less than 30 (%), it is determined that the test substance is not absorbed and the index can be regarded as antibody negative. Threshold value.

If the absorption rate A (%) is equal to or greater than 70 (%) in step S28, the process proceeds to step S29, and it is determined that a specific reaction has occurred 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 the display unit 19 determines that a nonspecific reaction may have intervened in the normal test.
A warning is issued by blinking the display of the normal inspection value in. In particular, when the value is less than 30 (%), it is determined that the value of the normal inspection is erroneous, and a warning to correct the result of the normal inspection is issued.

As described above, in the above embodiment, the dispensing unit 3 immediately determines that the normal inspection value indicates a value within the predetermined range.
The test sample is re-sampled and the test solution is supplied automatically, and the test is automatically performed.It is possible to check the presence or absence of a non-specific reaction in the normal test. Can be determined reliably and quickly.

[0035]

According to the immunoassay apparatus of the present invention, when the first measurement result is within a predetermined range, the sample is re-sampled by the absorption test supplementing means and the absorption test is performed. Therefore, an absorption test for confirming whether or not the first measurement result is a specific antigen-antibody reaction can be automatically performed in parallel with the normal test.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an immunoassay apparatus according to one embodiment of the present invention.

FIG. 2 is a control block diagram of the immunoassay apparatus of FIG.

FIG. 3 is a flowchart illustrating the operation of the immunoassay apparatus of FIG. 1;

FIG. 4 is a diagram showing an example of the absorption performance of a confirming absorbent.

[Explanation of symbols]

 Reference Signs List 1 detection unit 2 reaction unit 3 dispensing unit 4 reagent storage unit 10 immunoassay device 31 pipette (supplementary means for absorption test)

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] October 28, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

Claims (3)

[Claims] 1. An immune system comprising a sample storage unit for storing a sample to be measured, a reagent storage unit for storing a reagent of a measurement item, and a reaction unit for controlling an antigen-antibody reaction between the supplied sample and a reagent. In the measurement device, when the measurement result of the sample is within a predetermined range, the sample is re-sorted from the sample storage unit, and the sample and the confirming absorbent are supplied to the reaction unit, and the absorption test is performed. An immunoassay device comprising supplementary means. 2. The immunoassay apparatus according to claim 1, further comprising a warning display unit for performing a warning and a display based on the measurement result of the absorption test. 3. The immunoassay apparatus according to claim 1, further comprising correction display means for correcting and displaying the measurement result of the sample based on the measurement result of the absorption test.