JP7330869B2 - Automatic analysis method and automatic analysis device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a technique for automatically analyzing components of a test sample using latex agglutination reaction.

In the automatic analysis described above, test samples such as blood and urine collected from human specimens are mixed with reagents, and the amounts (concentrations) of the specified test items (measurements) contained in the test samples are measured. ) is automatically measured. Especially in automatic analysis using latex agglutination reaction, the concentration of the substance to be measured is quantified by optically measuring aggregates of latex particles.

When an antigen (analyte) contained in a test sample and a reagent containing latex particles whose surfaces are modified with antibodies are mixed, the antibodies on the surface of the latex particles react with the antigens, and the latex particles agglutinate with each other via the antigens. Agglomerates of latex particles are produced. The greater the change in the optical signal such as the intensity of transmitted light or scattered light with respect to the change (size or concentration) of aggregates due to this agglutination reaction, the more sensitively the measurement object can be quantified.

Patent Literature 1 discloses an automatic analyzer that measures scattered light intensity at a specific scattering angle. Patent Literature 2 discloses a method for detecting the state of aggregation by analyzing temporal variations in the intensity of scattered light scattered by aggregates using a correlation function.

JP 2015-7649 A JP-A-63-247644

However, in the automatic analyzer disclosed in Patent Document 1, the optimum angle for highly sensitive measurement of scattered light depends on the reaction liquid conditions such as the size, concentration, and aggregation state of the measured object and latex particles. different. In addition, it is susceptible to noise sources due to scattering other than aggregates, such as air bubbles in the reaction solution and scratches on the reaction vessel. On the other hand, Patent Document 2 does not disclose the quantification of the measured substance from the reaction process of the agglutination reaction.

The present invention provides an apparatus and method capable of automatically analyzing an object to be measured with a simple configuration and with high sensitivity.

An automatic analysis method according to one aspect of the present invention comprises irradiating a reaction solution in which an object to be measured and a reagent are mixed with irradiation light, and measuring the time variation of the intensity of the light emitted from the reaction solution by measuring the reaction in the reaction solution. and a processing step of processing the signal obtained in the measuring step to analyze the object to be measured. The processing step obtains first data indicating a value related to autocorrelation as a function of reaction time using the measurement result of the time variation of the intensity of the emitted light, and uses the first data to obtain second data related to the reaction rate. By acquiring data and comparing the second data with calibration data when the concentration of the measured substance is known, the concentration of the measured substance in the reaction liquid is quantified. A computer program that causes a computer to execute processing according to the automatic analysis method also constitutes another aspect of the present invention.

According to another aspect of the present invention, an automated analyzer includes irradiation means for irradiating a reaction liquid in which an object to be measured and a reagent are mixed with irradiation light; It has a measuring means for measuring the reaction time from the start of the reaction in the liquid and a processing means for processing the signal obtained in the measuring step to analyze the measured object. The processing means acquires first data indicating a value related to autocorrelation as a function of reaction time using the measurement result of the time variation of the intensity of the emitted light, and uses the first data to obtain second data related to the reaction rate. By acquiring data and comparing the second data with calibration data when the concentration of the measured substance is known, the concentration of the measured substance in the reaction liquid is quantified.

According to the present invention, an object to be measured can be automatically analyzed with high sensitivity with a simple configuration.

1 is a diagram showing the configuration of an automatic analyzer that is Embodiment 1 of the present invention. FIG. 4 is a flow chart showing the flow of measurement and processing in Example 1. FIG. 4A and 4B are diagrams showing measurement examples of an autocorrelation function in Example 1. FIG. 4 is a diagram showing an example of reaction rate measurement in Example 1. FIG. FIG. 4 is a diagram showing an example of measurement of calibration data in the embodiment; 6 is a flow chart showing the flow of measurement and processing in Example 2 of the present invention. FIG. 10 is a diagram showing a measurement example in Example 2; FIG. 10 is a diagram showing the configuration of another automatic analyzer in Example 2; The figure which shows the structure of the automatic analyzer which is Example 3 of this invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the principle of the automatic analysis method in the embodiment of the present invention will be explained. In this automatic analysis method, the test sample is irradiated with light, the time variation (temporal fluctuation) of the intensity of the scattered light emitted from the test sample is measured, and the measurement results are analyzed by the dynamic light scattering method (DLS: Use the principle of Dynamic Light Scattering. In the embodiment, light is applied to a reaction liquid in which a test sample and a reagent are mixed.

In the reaction solution, the latex particles and their aggregates in the sample and the reagent move in random directions due to Brownian motion, and the larger the particles, the slower the movement speed. Therefore, when the time variation of the intensity of the scattered light emitted from the reaction solution is evaluated using, for example, an autocorrelation function, small particles are observed with a short correlation time, and large particles are observed with a long correlation time.

In general, the autocorrelation function can be expressed by an exponential function such as exp(-Γτ) (τ is the delay time). The autocorrelation function with a long correlation time has a small Γ. In the examples, the changes in the aggregates are taken as changes in the dynamic characteristics of the scattered light with respect to the reaction time, which is the elapsed time from the start of the latex agglutination reaction (at the start of the reaction). Quantify the concentration of the measured substance. Specific examples of the present invention will be described below.

FIG. 1 shows the configuration of an automatic analyzer 100 that implements the automatic analysis method of this embodiment. The light source 110 is a laser that emits light with wavelengths in the visible band to the near-infrared band of 400 to 1100 nm. For example, a He--Ne laser with a wavelength of 633 nm can be used. The wavelength of the light emitted by the light source 110 may be appropriately selected according to the conditions of the object to be measured and the reagent.

Irradiation light 160 emitted from the light source 110 is collimated by an irradiation optical system (not shown) and enters the reaction container (reaction cell) 150 perpendicularly to its side surface. The light source 110 and the irradiation optical system constitute irradiation means. A reaction container 150 contains a reaction liquid 151 in which a test sample containing an object to be measured and a reagent containing latex particles are mixed. Aggregates of latex particles are generated in the reaction liquid 151 depending on the reaction conditions such as the concentration of the substance to be measured, the size and concentration of the latex particles, and the reaction time after mixing the test sample and the reagent. In addition, before the irradiation light 160 enters the reaction vessel 150 , the reaction liquid 151 is stirred by a stirring unit (not shown) so that the reagent containing the latex particles is uniformly dispersed in the reaction liquid 151 . After the test sample is mixed with this reaction liquid 151 and stirred again, the measurement is started.

The irradiation light 160 propagates through the reaction liquid 151 after entering the reaction liquid 151 . Then, emitted light 170 as scattered light traveling at various angles is emitted from the reaction container 150 (reaction liquid 151). In the automatic analyzer 100 , emitted light 170 emitted at a certain angle θ is condensed by the lens 120 and received by the detector 130 . The detector 130 is a sensor with a high response speed, and uses, for example, an avalanche photodiode (APD) or a photomultiplier tube (PMT). Detector 130 measures the intensity of emitted light 170 within a measurement time, which is a predetermined constant time, to measure the time variation of the intensity. The time resolution in the measurement at this time is about several tens of nanoseconds. The measurement time for measuring the time variation of the intensity of the emitted light 170 can be arbitrarily set according to the latex particles used as the reagent and the test sample. For example, the measurement time is set between several microseconds and several seconds.

In the automatic analyzer 100, the above measurement is performed multiple times according to the reaction time during the measurement time from the time when the test sample and the reagent are mixed until the end of the measurement.

The intensity of the light emitted from the light source 110 can be appropriately adjusted according to the signal level measured by the detector 130 as calibration before starting the reaction. Detector 130 is arranged to measure backscattered light with illumination light 160 from light source 110 as an optical axis. For example, θ in the figure is about 5 to 20 degrees. However, detector 130 may be positioned to measure forward scatter. Since the distribution of emitted scattered light varies depending on the reaction conditions such as the size of the latex particles and the concentration of the reaction solution, the detector 130 may be appropriately arranged according to the reaction conditions.

The electrical signal output from the detector 130 is transferred to the processing section 140 . The processing unit 140 converts the electrical signal into data, and analyzes the measurement object in the test sample by processing the data, which will be described later. The processing unit 140 acquires analysis data according to the elapsed time, stores the analysis data in the memory at any time, and performs analysis while reading the analysis data as appropriate. The analysis result at this time may be output to a display unit (not shown) such as a monitor.

The flowchart in FIG. 2 shows the flow of measurement and processing in this embodiment. Measurement of the reaction time starts when the test sample and the reagent are mixed and stirred in the reaction container 150 . A computer (PC) 101 that is part of the automatic analyzer 100 executes this process according to a computer program. The computer 101 functions as a measuring means together with the detector 130 and also functions as a processing means. S means step.

First, in S101, the computer 101 measures the time variation of the intensity of the scattered light 170 (hereinafter also referred to as light intensity) in correspondence with the reaction time T. FIG. Specifically, the computer 101 measures the time variation of the light intensity according to the range of the delay time τ of the autocorrelation function G(τ) to be calculated in S102, which will be described later. At this time, the same measurement may be performed multiple times and the multiple measurement results may be averaged. S101 corresponds to a measurement step.

Next, in S102, the computer 101 calculates the autocorrelation function G(τ) using the measurement result of the time variation of the measured light intensity. At this time, the autocorrelation function G(τ) may be calculated in real time in accordance with the measurement in S101 at the delay time τ. In this case, S101 and S102 are repeated until the range of delay time τ is reached. Steps after S102 correspond to processing steps.

After completing S102 and acquiring the autocorrelation function G(τ), the computer 101 fits the autocorrelation function G(τ) using the first model in S103. In this embodiment, the exponential function exp(-Γτ) is used as the first model. In S103, the computer 101 calculates the exponential attenuation coefficient Γ from the measured autocorrelation function G(τ) by the above fitting. The calculated attenuation coefficient Γ can be expressed as Γ(T) as a function of the reaction time T, and this is used as first data. The damping factor Γ corresponds to a value related to autocorrelation.

Next, in S104, the computer 101 determines whether or not the reaction time T has reached a predetermined time. This predetermined time is set according to conditions such as the reaction time of the agglutination reaction of the test sample and the measurement speed of the automatic analyzer 100 . For example, the predetermined time is set as 5 minutes. If the reaction time T has not reached the predetermined time, the computer 101 returns to S101 and performs the processing of S101 to S103. At this time, the timing of the measurement in S101 may be adjusted so that the reaction time T is sampled at certain time intervals with respect to a predetermined time.

FIG. 3 shows an example of measurement results of the autocorrelation function G(τ) when measuring the agglutination reaction of polystyrene particles with a diameter of 220 nm. It can be confirmed that the attenuation of the autocorrelation function G(τ) decreases with the reaction time T. When S104 in FIG. 2 ends, the computer 101 calculates the attenuation coefficient Γ at each reaction time T within the predetermined time range. Plotting the attenuation coefficient Γ as a function Γ(T) of the reaction time T using the measurement results shown in FIG. 3 results in the black circles in FIG. FIG. 4 shows plotted values normalized by the value of the attenuation coefficient Γ(0) at the start of the reaction. That is, it indicates the relative change of Γ during the reaction process.

In this embodiment, the attenuation coefficient Γ normalized in this manner is used as the first data. Any normalization method other than the above may be used as long as the change in the attenuation coefficient Γ due to the agglutination reaction can be measured. For example, the amount of change in the attenuation coefficient Γ (Γ(T)−Γ(0)) may be used as the first data.

Next, in S105, the computer 101 fits the first data Γ(T) using the second model. The dashed line shown in FIG. 4 indicates the result of fitting using the exponential function exp(-γT) as the second model. The fitting yields the value of the parameter γ, which is used as the second data. γ is a parameter related to the rate of change of the attenuation coefficient Γ with respect to the reaction time T, that is, the aggregation rate (or reaction rate). Thus, the computer 101 calculates the value of γ representing the aggregation rate.

FIG. 5( a ) shows the results of measuring the attenuation coefficient Γ(T) while varying the concentration of the substance to be measured in the reaction liquid 151 . The plotted points in the figure are the first data, and the solid line, dashed line and dashed line show the results of fitting using the second model. The computer 101 measures the attenuation coefficient Γ(T) in advance as described above using a standard sample having a known concentration of the substance to be measured, and further measures the aggregation rate γ in correspondence with the concentration ρ of the substance to be measured. . Then, as shown simply in FIG. 5(b), calibration data ρ(γ) is created from the relationship between the aggregation rate γ and the concentration ρ.

Next, in S106, the computer 101 calculates the concentration ρ of the measured substance using the calibration data ρ(γ) and the aggregation rate γ calculated in S105. As the calibration data, the result of fitting the data ρ(γ) obtained by measuring the aggregation rate γ at various concentrations ρ using the third model may be used. FIG. 5(b) shows the results of linear fitting as an example.

As the first to third models, the model that minimizes the difference between the calibration data created as shown in FIG. 5 using standard samples of various concentrations and the results of fitting using several models is selected. For this reason, a fitting model is generated in advance with the calibration data. That is, when calibration data is selected for a test sample to be measured, models to be used simultaneously (the first model in S103 and the second model in S105) are also automatically selected. Moreover, it is desirable that the measurement of the test sample and the measurement of the standard sample for generating the calibration data be performed under the same conditions.

As described above, the present embodiment utilizes the principle of DLS, and is not intended to measure the accurate particle size distribution of particles in a test sample as in the case of using conventional DLS. The purpose of this example is to measure the reaction rate as a change in the signal (attenuation coefficient Γ) in the course of the agglutination reaction, and to quantify the concentration of the substance to be measured from the reaction rate. A feature of this embodiment is that temporal fluctuations in the scattered light intensity are used as a signal that captures this change.

In addition, in this example, compared to the method of measuring the light intensity at a specific scattering angle as disclosed in Patent Document 1, in order to obtain data on the temporal autocorrelation of the light intensity, aggregates in the agglutination reaction size changes can be sensitively measured.

Furthermore, since this embodiment can measure a particle size of several nanometers, it is also possible to use such a micro-sized reagent. One of the advantages of using micro-sized reagents is that the surface area for antigen-antibody reaction can be increased. analysis becomes possible. Further, as the particle size becomes smaller, the attenuation coefficient Γ of the autocorrelation function G(τ) becomes larger (the correlation time becomes shorter), so the measurement time can be shortened. In addition, in such a short correlation time, the effect of scattering due to impurities of several micrometers or more, mechanical vibration of the device, etc. do not affect the autocorrelation function G(τ), so noise such as these can be removed. be able to.

Note that in S103, the value of the delay time τ when the autocorrelation function G(τ) becomes a certain value _Gref instead of the attenuation coefficient Γ may be evaluated as the first model. For example, when G _ref =0.5, τ _ref when G(τ _ref )=G _ref is obtained, and the delay time τ _ref (T) with respect to the aggregation time T may be evaluated as the first data. . However, depending on the particle _diameter of the reagent particles, if G _ref is large, it may be difficult to capture the change due to the agglutination reaction. Including this G _ref , calibration data can be obtained by adjusting when measuring a standard sample.

In addition, in this embodiment, the first model and the second model are modeled using mathematical functions, but it is also possible to use a database obtained by acquiring data comprehensively to some extent and tabulating it. . Any model can be used for the first to third models as long as it can accurately reproduce the measurement results, and is selected together with the calibration data.

Next, an automatic analysis method as Example 2 of the present invention will be described. The automatic analysis method of this embodiment is performed by the automatic analysis apparatus 100 shown in the first embodiment. The flowchart of FIG. 6 shows the flow of measurement and processing in this embodiment. Also in this embodiment, the computer 101, which is part of the automatic analyzer 100, executes according to the computer program. S means step.

First, in S201, the computer 101 sets the delay time τ _ref to be evaluated. This delay time τ _ref is set with the calibration data as described in the first embodiment. That is, when calibration data is selected for the test sample before measurement, the delay time τ _ref for automatic evaluation is set. Depending on the concentration, the delay time τ _ref is chosen so that changes in aggregation can be measured sensitively. Specifically, the delay time τ _ref is set short for small particle sizes, and the delay time τ _ref is set long for large particle sizes.

The computer 101 starts measurement after the test sample and the reagent are mixed in the reaction container 150 and stirring is completed. In S202 after the start of the measurement, the computer 101 measures the time variation of the intensity (light intensity) of the scattered light 170 corresponding to the reaction time T. FIG. Here, basically, two data are measured: the light intensity I(t) at the timing of the delay time τ=0 and the light intensity I(t+τ _{ref ) at the timing of the delay time τ=τ ref .} However, the above two data may be measured a plurality of times according to the SN of the signal and averaged.

Next, in S203, the computer 101 obtains a correlation value C (=<I(t)·I(t+τ _ref )>/<I(t)> ² ) between the two data obtained in S202. <> represents the time average. This correlation value C corresponds to the value G(τ=τ _{ref ) at the delay time τ=τ ref in} the autocorrelation function G(τ) described in the first embodiment. That is, the correlation value C is a value related to autocorrelation. Thus, computer 101 calculates correlation value C as a function of reaction time T. FIG. In this embodiment, the calculated correlation value is used as the first data. Therefore, unlike the first embodiment, fitting using the first model is not performed on the measurement results.

Next, in S204, the computer 101 determines whether or not the reaction time T has reached a predetermined time, as in the first embodiment. If the reaction time T has not reached the predetermined time, the process returns to S201. Then, the processing of S201 to S203 is performed.

After completing S204, in S205, the computer 101 performs fitting of the correlation value C(T) as a function of the measured reaction time T using the second model. Then, from the result of this fitting, the rate of change of the correlation value C with respect to the reaction time T, that is, the value of the parameter γ relating to the aggregation rate (hereinafter referred to as the aggregation rate) is calculated. In this embodiment, the value of this aggregation rate γ is used as the second data.

The computer 101 that has calculated the parameter γ refers to the calibration data measured using the standard sample to calculate the sample concentration corresponding to the aggregation rate γ in S206.

FIG. 7 shows the result of evaluating a part of the attenuation coefficient Γ(T) shown in FIG. 5(a) in Example 1 using the correlation value C. 0) is normalized. FIG. 7 shows an example in which the correlation value C(T) at the reaction time T is fitted using a straight line as the second model. The slope of the solid line and broken line in FIG. 7 is the aggregation rate γ. As calibration data, the computer 101 creates calibration data obtained by measuring the correspondence between the concentration and the aggregation rate γ for the measurement substance having different concentrations in the test sample, based on the correlation value C(T). At this time, the condition of the delay time τ _ref for obtaining the correlation is also prepared as a set with the calibration data.

Also using this example, it is possible to quantify the change in the attenuation coefficient Γ (reaction rate) in the reaction process of the agglutination reaction. In this embodiment, the correlation between the time variations of two light intensities corresponding to an arbitrary delay time τ _ref can be calculated. Therefore, it is not necessary to calculate the autocorrelation function G(τ) while changing the delay time τ, and the time required for measurement and processing can be shortened.

FIG. 8 shows a modification of the automatic analyzer in this embodiment. This modification is an example in which the angle θ in the automatic analyzer 100 shown in FIG. 1 is set to θ=90°. It has a configuration for receiving light at The scattering angle θ at which the light intensity is measured in this manner may be arbitrarily selected according to the scattering concentration of the reaction liquid 151 . Moreover, the angle θ at which the detector 130 is arranged may be in a plane parallel to or perpendicular to the propagation direction of the irradiation light 160 .

FIG. 9 shows an automatic analyzer 10 that is Embodiment 3 of the present invention. The automatic analyzer 10 has an analysis section 20 , a measurement section 22 , a control section 30 , a processing section 40 and a memory 50 . The control unit 30 controls the measurement processing performed by the measurement unit 22, receives signals output from the measurement unit 22, controls the processing unit 40 and the memory 50, and executes data transfer, data processing, and data storage. The automatic analyzer 10 has a display section 60 that displays the results processed by the processing section 40 .

The analysis unit 20 includes a rotatable disc 21 and a plurality of reaction vessels 23 arranged in the circumferential direction of the disc 21 . The measurement unit 22 rotates with the disk 21 and irradiates the reaction liquid in the reaction container 23 passing through the measurement position with irradiation light, and measures the time variation of the intensity (light intensity) of the scattered light emitted from the reaction container 23. Measure.

The analysis unit 20 includes a sample dispensing unit 24 that dispenses a sample such as a standard sample or a test sample into a reaction container 23, and a first reagent dispensing unit that dispenses a first reagent that reacts with a component contained in the sample. 25 and a second reagent dispensing unit 26 that dispenses a second reagent paired with the first reagent. Further, the analysis unit 20 includes a stirring unit 27 that agitates the mixed solution of the sample and the reagent, and a cleaning/drying unit 28 that sucks the measured mixed solution from the reaction container 23 and cleans and dries the inside of the reaction container 23 . Prepare. The automatic analyzer 10 having such a configuration can continuously perform a series of processes including sample/reagent dispensing, stirring, measurement, suction, washing, and drying while rotating the disk 21 . The reaction vessel 23 is housed in a constant temperature bath, and the temperature of the reaction solution is kept constant.

When the reaction container 23 is filled with the reaction liquid and stirred, the disc 21 is driven to rotate. Measurement by the measurement unit 22 is performed on the reaction container 23 at the position of . The measurement unit 22 is configured by the automatic analyzer 100 shown in Example 1 (FIG. 1) or Example 2 (FIG. 8). For example, when the measuring unit 22 is the automatic analyzer 100 shown in the first embodiment, the irradiation light 160 is irradiated from the light source 110 to the reaction container 150 at the timing when the rotating reaction container 23 passes the measuring unit 22, and emitted. Scattered light 170 is received by detector 130 . A signal output from the detector 130 is transferred to the control section 30 , stored in the memory 50 , and processed by the processing section 40 . The measurement is performed each time the reaction vessel 23 passes the measurement unit 22 while the disk 21 is rotating. Second data γ on the reaction rate are calculated from the first data.

As in this embodiment, the automatic analysis described in Embodiments 1 and 2 can also be performed in an apparatus that continuously performs a series of processes from sample/reagent dispensing, stirring, measurement, aspiration, washing, and drying. A method can be implemented. Similarly, calibration data can be measured in advance using the automatic analyzer 10 of the present embodiment, and the measured object can be analyzed according to the measurement conditions.
(Other examples)
The present invention supplies a program that implements one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and one or more processors in the computer of the system or device reads and executes the program. It can also be realized by processing to It can also be implemented by a circuit (for example, ASIC) that implements one or more functions.

Each embodiment described above is merely a representative example, and various modifications and changes can be made to each embodiment in carrying out the present invention.

101 computer 151 reaction liquid 110 light source 130 detector

Claims (10)

A reaction solution in which an object to be measured and a reagent are mixed is irradiated with irradiation light, and time fluctuations in the intensity of light emitted from the reaction solution are associated with the reaction time from the start of the reaction in the reaction solution. a measuring step to measure;
a processing step of processing the signal obtained in the measuring step to analyze the measured object;
The processing step includes:
obtaining first data indicating a value related to autocorrelation as a function of the reaction time using the measurement result of the time variation of the intensity of the emitted light;
obtaining second data on the reaction rate using the first data;
An automatic analysis method, wherein the concentration of the substance to be measured in the reaction solution is quantified using the second data and calibration data when the concentration of the substance to be measured is known. 2. The automatic analysis method according to claim 1, wherein the value related to autocorrelation is an autocorrelation function in time variation of the intensity of the emitted light. 3. The automatic analysis method according to claim 2 , wherein said processing step obtains said first data by fitting said autocorrelation function based on a first model. The first model is an exponential function,
4. The automatic analysis method according to claim 3, wherein said processing step acquires said first data by calculating an attenuation coefficient in said exponential function by said fitting. 2. The automatic analysis method according to claim 1, wherein the autocorrelation value is a correlation value between data obtained by measuring time fluctuations of the intensity of the emitted light at a selected delay time. . The processing step selects a second model based on the first data, and obtains the second data by fitting the first data using the second model. The automatic analysis method according to any one of claims 1 to 5. 7. The method according to any one of claims 1 to 6, wherein the processing step acquires the first data and the second data using the same model as that used to generate the calibration data. or the automatic analysis method according to item 1. The automatic analysis method according to any one of claims 1 to 7, wherein the first data is a signal obtained by normalizing the signal for the reaction time with the signal at the start of the reaction. A computer program that causes a computer to execute processing according to the automatic analysis method according to any one of claims 1 to 8. an irradiating means for irradiating a reaction liquid in which an object to be measured and a reagent are mixed with irradiation light;
measuring means for measuring the time variation of the intensity of the light emitted from the reaction solution in correspondence with the reaction time from the start of the reaction in the reaction solution;
a processing means for processing the signal acquired by the measuring means and analyzing the measured object;
The processing means
obtaining first data indicating a value related to autocorrelation as a function of the reaction time using the measurement result of the time variation of the intensity of the emitted light;
obtaining second data on the reaction rate using the first data;
An automatic analyzer that quantifies the concentration of the substance to be measured in the reaction liquid using the second data and calibration data when the concentration of the substance to be measured is known.