EP-4737887-A2 - AUTOMATED ANALYTICAL APPARATUS AND AUTOMATED ANALYTICAL METHOD

EP4737887A2EP 4737887 A2EP4737887 A2EP 4737887A2EP-4737887-A2

Abstract

An automated analytical apparatus of an embodiment includes a light source unit (10), a reaction vessel (30), a detection unit (40), and a processor (70). The light source unit (10) emits at least two lights having different wavelengths. The reaction vessel (30) contains a reaction solution containing a mixture of a measurement object and a reagent. The detection unit (40) receives at least two emitted light of first emitted light and second emitted light having different wavelengths emitted from the reaction vessel (30) by radiating incident light emitted from the light source unit (10) to the reaction vessel (30). The processor (70) calculates a concentration of the measurement object based on a signal output from the detection unit (40). The first emitted light is fluorescence obtained by wavelength conversion of the incident light by the reagent. The detection unit (40) has a separation means (55) for separating the first emitted light and the second emitted light and receiving the separated first emitted light and second emitted light through photodetectors (58,68). The processor (70) calculates the concentration of the measurement object from at least one of two output signals output from the detection unit (40) in response to the first emitted light and the second emitted light.

Inventors

MASUMURA, TAKAHIRO
NAKAMURA, TOMOHIRO
KAKEGAWA, NORISHIGE

Assignees

Canon Medical Systems Corporation

Dates

Publication Date: 20260506
Application Date: 20251008

Claims (12)

An automated analytical apparatus comprising: a light source unit that emits at least two lights having different wavelengths; a reaction vessel that contains a reaction solution containing a mixture of a measurement object and a reagent specifically reacting with the measurement object; a detection unit that receives at least two emitted lights of first emitted light and second emitted light having different wavelengths emitted from the reaction vessel by radiating incident light emitted from the light source unit to the reaction vessel; and a processor configured to calculate a concentration of the measurement object based on a signal output from the detection unit, wherein the first emitted light is fluorescence obtained by wavelength conversion of the incident light by the reagent, the detection unit has a separation means for separating the first emitted light and the second emitted light and receiving the separated first emitted light and second emitted light through photodetectors, and the processor is configured to calculate the concentration of the measurement object from at least one of two output signals output from the detection unit in response to the first emitted light and the second emitted light.
The automated analytical apparatus according to claim 1, wherein the processor is configured to: evaluate signal changes in the output signals after a given time has elapsed since the start of a reaction in which the measurement object and the reagent are mixed; calculate a first signal change based on the first emitted light and a second signal change based on the second emitted light; and calculate the concentration of the measurement object based on the first signal change when the first signal change satisfies a predetermined condition, and calculate the concentration of the measurement object based on the second signal change when the first signal change does not satisfy the predetermined condition.
The automated analytical apparatus according to claim 2, wherein the reagent includes scattering particles containing fluorescent molecules, the first signal change is a signal change based on fluorescence anisotropy, and the second signal change is a signal change based on scattered light intensity or an autocorrelation function calculated from temporal fluctuations in scattered light intensity.
The automated analytical apparatus according to claim 2, wherein the reagent contains at least two antibodies with different affinities, each labeled with a fluorescent molecule that emits light at a different wavelength, and the first signal change and the second signal change are signal changes based on a fluorescence intensity of the fluorescence having a different wavelength.
The automated analytical apparatus according to any one of claims 1 to 4, wherein the separation means of the detection unit is a dichroic mirror that reflects light having a longer wavelength of two lights having different wavelengths and transmits light having a shorter wavelength.
The automated analytical apparatus of any one of claims 1 to 3, wherein the light source unit has a linear polarizer, and at least one of the lights emitted from the light source unit is linearly polarized and irradiates the reaction solution, and the detection unit has a polarization separation element, separates the first emitted light emitted from the reaction solution by the linearly polarized light into a direction parallel to and a direction orthogonal to a polarization direction of the linearly polarized light, and receives the separated lights through the photodetectors.
The automated analytical apparatus according to claim 5, wherein desired light received by the photodetector is incident on the dichroic mirror as s-polarized light and color-separated when A-C < C-B and incident on the dichroic mirror as p-polarized light and color-separated when A-C > C-B, C being a cut-off wavelength at which the reflectance of the dichroic mirror is 50%, A being the wavelength of light having the longer wavelength of the two lights having different wavelengths, and B being the wavelength of the light having the shorter wavelength.
The automated analytical apparatus according to any one of claims 1 to 4, wherein, with respect to light intensities of the photodetector receiving the first emitted light and the photodetector receiving the second emitted light, an output of a first light source generating an emitted light with a lower light intensity is greater than an output of a second light source, or a gain or exposure time of the photodetector receiving the emitted light with a lower light intensity is greater than that of the other photodetector.
The automated analytical apparatus according to any one of claims 1 to 4, further comprising a controller configured to alternately or sequentially turn on at least two light sources emitting lights having different wavelengths, wherein the detection unit alternately or sequentially receives the first emitted light and the second emitted light depending on turn-on times of the light sources.
The automated analytical apparatus according to any one of claims 1 to 4, wherein the lights emitted from the light source unit are incident through a first surface of the reaction vessel and emitted through a second surface opposite the first surface.
The automated analytical apparatus according to claim 2 or 3, wherein the predetermined condition includes comparing the first signal change with the second signal change, and calculating the concentration of the measurement object based on concentration change of the measurement object or the larger signal change with respect to the elapse of time.
An automated analytical method comprising: a radiation step of radiating at least two lights having different wavelengths to a reaction solution containing a mixture of a measurement object and a reagent specifically reacting with the measurement object; a light-receiving step of separately receiving at least two emitted light of a first emitted light and a second emitted light having different wavelengths emitted from the reaction solution; and a processing step of calculating a concentration of the measurement object based on a signal output in the light-receiving step, wherein the processing step calculates the concentration of the measurement object from at least one of a change in the signal based on the first emitted light and a change in the signal based on the second emitted light.

Description

FIELD Embodiments disclosed in this specification and drawings relate to an automated analytical apparatus and an automated analytical method for analyzing the components of a test sample using antigen-antibody reactions. BACKGROUND In sample testing methods using antigen-antibody reactions, fluorescence polarization using the polarization properties of fluorescence has been known. Fluorescence polarization radiates linearly polarized excitation light to a mixture (reaction solution) of a test sample containing a test item (measurement object) and a fluorescent reagent, measures the fluorescence intensity emitted from the reaction solution by polarization resolution, and evaluates the degree of polarization (polarization anisotropy or anisotropy). The value of this anisotropy is highly sensitive to the rotational motion of the measurement object, and the rotational motion depends on the size of the measurement object. In antigen-antibody reactions, when a measurement object (antigen) is mixed with an antibody-modified reagent, the antigen and antibody react specifically and bind, forming aggregates. Therefore, it is possible to detect changes in the size of a measurement object (agglutination reaction) with high sensitivity by measuring anisotropy. The relationship between change in the size of a measurement object and the measured anisotropy depends on the concentration relationship between the measurement object and a reagent. If the relationship between the concentration of the measurement object and the measured anisotropy is obtained in advance as a calibration curve using known amounts of reagent, it is possible to calculate the concentration of the measurement object from anisotropy measurement results. Patent Document 1 (Japanese Patent No. 1692254) discloses an analytical apparatus that uses this fluorescence polarization. Patent Document 2 (Japanese Patent No. 6013796) discloses an apparatus that analyzes agglutination reactions by measuring the intensity of transmitted light or scattered light emitted from a reaction solution. Furthermore, Patent Document 3 (Japanese Unexamined Patent Application, First Publication No. 2007-120976) discloses an apparatus that performs analysis by simultaneously measuring fluorescence polarization and the intensity of transmitted light or scattered light. SUMMARY According to fluorescence polarization disclosed in Patent Document 1, it is possible to detect a measurement object of a very low concentration with high sensitivity by optimally adjusting the amount of a reagent to be mixed in. However, under such conditions in which the reagent is adjusted for highly sensitive detection, the measurable concentration range is limited to a low concentration range. If the concentration of the measurement object exceeds this concentration range, the anisotropy value saturates at a constant value regardless of the concentration of the measurement object, resulting in no sensitivity to the concentration of the measurement object. On the other hand, adjusting the amount of reagent to enable measurement in a high-concentration range reduces measurement sensitivity in a low-concentration range. Thus, the fluorescence polarization has the problem of being unable to achieve both high sensitivity and a wide concentration range. On the other hand, Patent Document 2 discloses an automated analytical method that simultaneously measures transmitted light and scattered light and selects the optimal measurement method depending on the concentration range of a measurement object. That is, by combining two measurement methods with different sensitivities, the measurement range can be extended. However, Patent Document 2 does not disclose fluorescence polarization. Furthermore, as pointed out in the text of Patent Document 2, if it is not known which measurement method can be used to measure with high accuracy in which concentration range, there is no value in combining different measurement methods. Patent Document 3 also discloses an immunoassay that simultaneously measures fluorescence polarization and the intensity of transmitted or scattered light to calculate the modification rate of a modified protein. However, in Patent Document 3, since a portion of the scattered light that is not wavelength-converted is received by a fluorescence polarization detector, the modified protein is detected at an apparently higher level, making it impossible to calculate the modification rate with high accuracy. An object to be achieved by embodiments disclosed in this specification and drawings is to provide an automated analytical apparatus and an automated analytical method capable of analyzing the concentration of a measurement object with high sensitivity over a wide range from low to high concentrations. However, the object to be achieved by the embodiments disclosed in this specification and drawings is not limited to the above object. Objects corresponding to the effects of each configuration s