Automatic analysis device

Abstract

The purpose of the present invention is to provide an automatic analysis device capable of highly reliable analysis in a situation where a light emission amount fluctuates, while suppressing device enlargement and degradation of processing performance. For this purpose, the automatic analysis device of the present invention comprises: a vessel holding part capable of holding a plurality of vessels containing a reaction solution produced by mixing a specimen and a reagent; a light source that emits light; an optical receiver that receives the light emitted by the light source; and a control unit that performs measurement pertaining to light, based on a signal outputted by the optical receiver. The vessels are disposable. The control unit corrects measurement values pertaining to light emitted in positions where the vessels are held in the vessel holding part, on the basis of measurement values pertaining to light emitted in positions where the vessels are not held in the vessel holding part.

Description

automatic analyzer

[0001] The present invention relates to an automatic analyzer.

[0002] In an automatic biochemical analyzer that measures the concentration of components in a sample using absorbance, a waiting time is required after the power is turned on until the light source's light intensity stabilizes. Furthermore, the light source's light intensity may fluctuate due to temperature changes in the environment in which the analyzer is installed. Patent Document 1 discloses a technique for measuring and correcting the reference light intensity when no reaction vessel is present by providing a light path separate from the position where the reaction vessel is held, or by alternately providing positions where the reaction vessel is held and positions where the reaction vessel is not held.

[0003] Japanese Patent Application Laid-Open No. 2007-322246

[0004] According to Patent Document 1, providing a separate optical path between adjacent container holding positions leads to an increase in the size of the device and a decrease in processing capacity. Furthermore, since this is an automatic analyzer that cleans reaction containers after analysis and reuses them, if positions that do not hold reaction containers exist alternately, cleaning is difficult using a general cleaning mechanism that can simultaneously clean multiple reaction containers.

[0005] An object of the present invention is to provide an automatic analyzer that can perform highly reliable analysis even under conditions where the amount of luminescence fluctuates, while suppressing an increase in size of the apparatus and a decrease in processing capacity.

[0006] In order to achieve the above-mentioned object, the automatic analyzer of the present invention comprises a container holding unit capable of holding multiple containers containing a reaction liquid produced by mixing a sample and a reagent, a light source that irradiates light, a light receiver that receives the light irradiated by the light source, and a control unit that performs light-related measurements from the signal output by the light receiver, wherein the containers are disposable containers, and the control unit corrects the measurement value related to light irradiated to a position in the container holding unit where the container is held based on the measurement value related to light irradiated to a position in the container holding unit where the container is not held.

[0007] According to the present invention, it is possible to provide an automatic analyzer that can perform highly reliable analysis even under conditions where the amount of luminescence fluctuates, while suppressing an increase in size of the apparatus and a decrease in processing capacity.

[0008] 3A ; a horizontal cross-sectional view of an incubator; a cross-sectional view of an incubator taken along the line A-A in FIG. 3A ... time chart showing operations performed for a first position and a second position in the incubator; a graph showing the transitions of the light intensity obtained by reaction solution measurement, the light intensity obtained by blank photometry, and the light intensity after correction for reaction solution measurement.

[0009] Hereinafter, an embodiment will be described with reference to the drawings.

[0010] Figure 1 is a top view showing the overall configuration of an automated analyzer. A plurality of reaction vessels 2 are arranged circumferentially around the outer periphery of an incubator 1 (a vessel holder), which is rotated by a drive mechanism (not shown) over a distance equivalent to a predetermined number of reaction vessels in one cycle. The reaction vessels 2 are the same for all reactions and are disposable.

[0011] A plurality of reagent bottles 4 and specimen containers 5 can be mounted circumferentially on the reagent / specimen common disk 3 (hereinafter referred to as the common disk). In this embodiment, the reagent bottles 4 are located on the inner periphery of the specimen containers 5, but the specimen containers 5 may be located on the inner periphery of the reagent bottles 4, or may be located without being separated into the inner and outer peripheries. Furthermore, the reagents and specimens may be configured on separate disks.

[0012] A first dispensing mechanism 8 and a second dispensing mechanism 9, which are rotatable and movable up and down, are installed between the incubator 1 and the common disk 3, and each dispensing mechanism is equipped with a dispensing nozzle. A first dispensing mechanism pump 10 is connected to the dispensing nozzle of the first dispensing mechanism 8, and a second dispensing mechanism pump 11 is connected to the dispensing nozzle of the second dispensing mechanism 9.

[0013] The first aliquot dispensing mechanism 8 and the second aliquot dispensing mechanism 9 are used for different analytical processes. If the first aliquot dispensing mechanism 8 is used for biochemistry and the second aliquot dispensing mechanism 9 is used for immunology, the second aliquot dispensing mechanism 9 for immunology uses a dispensing tip 18 because there is a high need to prevent contamination between specimens. The first aliquot dispensing mechanism 8 dispenses specimens and reagents for biochemical testing. The second aliquot dispensing mechanism 9 dispenses specimens and reagents for immunology testing. Both the first aliquot dispensing mechanism 8 and the second aliquot dispensing mechanism 9 can access specimens that are to be tested for both biochemistry and immunology.

[0014] The dispensing nozzle moves in a horizontal arc around the rotation axis. The horizontal trajectory of the dispensing nozzle includes a reagent aspirating position 6 and a sample aspirating position 7 on the common disk 3, a first dispensing position and a second dispensing position on the incubator 1, and washing tanks for washing the dispensing nozzle (a first dispensing nozzle washing tank 12 and a second dispensing nozzle washing tank 13). Because the second dispensing mechanism 9 uses dispensing tips 18, a dispensing tip attachment position 22 and a dispensing tip disposal position 23 are also located on the trajectory.

[0015] The first dispensing mechanism 8 and the second dispensing mechanism 9 are positioned so that the trajectories and mechanisms of the dispensing nozzles do not interfere with each other. The specimen aspirated from the specimen container 5 at the specimen aspirating position 7 and the reagent aspirated from the reagent bottle 4 at the reagent aspirating position 6 are dispensed into the reaction vessel 2 at the first dispensing position or the second dispensing position. The specimen and reagent in the reaction vessel 2 are then mixed by the aspirating and dispensing operation within the reaction vessel 2 using the dispensing nozzle or the dispensing tip 18 attached to the dispensing nozzle.

[0016] The reaction vessel 2 containing the reaction solution in which the specimen and reagent are mixed is maintained at a predetermined temperature by the incubator 1, and the reaction is promoted. A spectrophotometer 15 for biochemical testing is arranged around the incubator 1. The spectrophotometer 15 measures the absorbance of the reaction solution by irradiating the reaction solution in which the specimen and reagent are mixed with light, and detecting the transmitted light through the spectrophotometer 15; the details of its structure will be described later with reference to FIG. 2.

[0017] The detection mechanism 16 for immunoassay measures the reaction solution that has been reacted for a predetermined time in the incubator 1. In immunoassays, methods for detecting labeled substances include those based on electrochemiluminescence and chemiluminescence, and the structure and physical properties of the label and detection region suitable for each are selected, and the amount of luminescence resulting from the luminescence reaction of the label is measured using a photomultiplier tube as a detector.

[0018] The transport mechanism 17 moves disposable reaction vessels 2 loaded in a reaction vessel tray 20 to the incubator 1, and discards reaction vessels 2 after absorbance measurement in the incubator 1 into a waste box 21. The transport mechanism 17 also moves reaction vessels 2 containing reaction liquid that has been reacted for a predetermined time in the incubator 1 to the detection mechanism 16, and discards reaction vessels 2 after measurement in the detection mechanism 16 into the waste box 21. The transport mechanism 17 also performs operations such as moving dispensing tips 18 loaded in a dispensing tip tray 19 to a dispensing tip mounting position 22.

[0019] The control unit 24 is connected to each mechanism (connection state not shown) and controls the rotational operation of the incubator 1, the rotational operation of the common disk 3, the operation of the dispensing nozzle, the suction and discharge of liquid, and the like.

[0020] FIG. 2 is a diagram showing the optical system of the automatic analyzer. As shown in FIG. 2, the optical system of the automatic analyzer includes a light source 101, a condenser lens 102, an illumination slit 103, a reaction vessel 2, a light-receiving slit 105, a concave diffraction grating 106, and a light receiver 107. In this embodiment, an LED is used as the light source 101. Light from the light source 101 is condensed by the condenser lens 102, the illumination range is limited by the illumination slit 103, and after entering the reaction vessel 2, the light is emitted at an amount of light corresponding to the absorbance of the reaction solution 104 in the reaction vessel 2. The emitted light has a reception range limited by the light-receiving slit 105, is dispersed by the concave diffraction grating 106, and is received by the light receiver 107. The amount of light received by the light receiver 107 for each wavelength is converted into an electrical signal, and the control unit 24 measures the absorbance based on the electrical signal output from the light receiver 107.

[0021] Fig. 3A is a horizontal cross-sectional view of the incubator, and Fig. 3B is a cross-sectional view taken along the line A-A in Fig. 3A. The incubator 1 is provided with a plurality of vessel insertion holes 62, into which reaction vessels 2 are inserted, spaced at predetermined equal intervals around a circumference. Note that although Fig. 3A shows 12 vessel insertion holes 62 arranged around a circumference, in reality, as shown in Fig. 1, 64 vessel insertion holes 62 are formed on the top surface of the incubator 1. Note that of the 64 vessel insertion holes 62, 32 are holes for biochemical testing, and the other 32 are holes for immunoassays.

[0022] Since the incubator 1 serves to raise and maintain the temperature of the reaction solution in the reaction vessel 2 to a predetermined temperature, it is preferably formed of a disk-shaped metal, but it may also be formed of a shape other than a disk or of a light-shielding material other than metal. Incubator 1 thus formed mainly of a light-shielding material has incident-side slits 63 and exit-side slits 64 formed in the radial direction as shown in FIG. 3B , which serve as an optical path for light from light source 101 to pass through reaction vessel 2 and reach the light receiver. Note that, by not providing slits for vessel insertion holes 62 into which only reaction vessels 2 for immunoassays that do not involve absorbance measurement are inserted, temperature control performance may be improved or the effects of light irradiation on the immunoassay reagents may be eliminated.

[0023] 4 is a cross-sectional view showing a state in which a reaction vessel is inserted into a vessel insertion hole in an incubator. Light emitted from light source 101 and passing through entrance slit 63 passes through reaction solution 104 in reaction vessel 2 and emits light with an amount of light corresponding to the absorbance of reaction solution 104. The emitted light passes through exit slit 64 and enters spectrophotometer 15, where it is dispersed and the amount of light for each wavelength is measured. Here, because the cylindrical portion of reaction vessel 2 is in close contact with incubator 1, heat is transferred from incubator 1, which is controlled to a constant temperature, to reaction vessel 2 and reaction solution 104, and they are quickly heated to the same temperature as incubator 1.

[0024] The operation of the automatic analyzer when measuring the absorbance of a reaction solution as a biochemical test will be specifically described below with reference to Fig. 5. Fig. 5 is a time chart showing the operations executed for the first and second positions of the incubator.

[0025] First, the user issues a start command to perform an initial operation (reset operation) of each mechanism. At this time, it is assumed that no reaction vessel 2 is held in any of the 32 vessel holding positions for biochemical testing in the incubator 1. Note that the vessel holding position in this specification indicates a circumferential position of the incubator 1 that corresponds to the location of the vessel insertion hole 62, and in particular refers to the portion that becomes the light irradiation area when the reaction vessel 2 is inserted into the vessel insertion hole 62 and held by the vessel holder.

[0026] In the first cycle (cycle C1), the control unit 24 controls the transport mechanism 17 to move a pre-used reaction vessel 2 from the reaction vessel tray 20 and place the reaction vessel 2 at a first position, which is one of the multiple vessel holding positions in the incubator 1 and is a transport position, and then rotates the incubator 1. During this time, the incubator 1 rotates more than once, so that all vessel holding positions pass in front of the photometry unit (light source 101), and the amount of transmitted light obtained by irradiating each vessel holding position is measured by the spectrophotometer 15. A first blank measurement (BK1) is performed for the first position where a reaction vessel 2 is held, and blank photometry is performed for the second position where no reaction vessel 2 is held and other vessel holding positions. The measurement value obtained in the first blank measurement for the first position is corrected by the measurement value obtained in blank photometry for the second position in this cycle. Note that, since there are multiple vessel holding positions where blank photometry is performed in this cycle, the average value of these blank photometry measurements may be used to correct the measurement value at the first position. Alternatively, among the multiple container holding positions where aerial photometry is performed, the measurement value of aerial photometry at the container holding position whose irradiation timing (timing of passing through the photometry unit) is closest to the first position may be used to correct the measurement value at the first position.

[0027] In this specification, blank measurement refers to a measurement of the light intensity that is performed when the reaction vessel 2 is empty and has no reaction solution, even if the reaction vessel 2 is present in the vessel holding position, and is a measurement to correct for individual differences and contamination of the disposable reaction vessel 2. In this embodiment, blank measurements are performed three consecutive cycles for the same reaction vessel 2, and the average of the three measured values ​​is used for correction. Note that, as described above, the automated analyzer of this embodiment uses disposable reaction vessels 2 and is not equipped with a cleaning mechanism that dispenses or sucks water or detergent into the reaction vessel 2, and therefore does not perform a measurement of the light intensity when water is present in the reaction vessel 2 (water blank measurement).

[0028] In this specification, blank photometry refers to the measurement of the light intensity performed without the reaction vessel 2 being present at the vessel holding position, and is a measurement for canceling out fluctuations in the amount of light emitted (emission intensity) of the light source 101. The measurement value in blank photometry is the actual amount of light emitted by the light source 101, which may change as the cycle progresses. Therefore, the measurement values ​​of the blank measurement in each cycle and the reaction solution measurement described below are corrected by the measurement values ​​of blank photometry measured at other vessel holding positions in the same cycle.

[0029] In the second cycle (cycle C2), the control unit 24 rotates the incubator 1 to perform a second blank measurement (BK2) at the first position and perform empty measurements at the second position and other container holding positions. The measurement value obtained in the second blank measurement at the first position is also corrected by the measurement value obtained in the empty photometry of this cycle at the second position and other container holding positions.

[0030] In the third cycle (cycle C3), the control unit 24 controls the transport mechanism 17 to move a new, unusable reaction vessel 2 from the reaction vessel tray 20 and place the reaction vessel 2 at a second position, which is one of the multiple vessel holding positions in the incubator 1 and is a transport position, and then rotates the incubator 1. As the incubator 1 rotates, a third blank measurement (BK3) is performed at the first position and a first blank measurement (BK1) is performed at the second position. In this cycle, blank photometry is also performed at the other vessel holding positions where no reaction vessel 2 is held, and the measurement values ​​at the first and second positions are corrected based on the measurement values ​​obtained by these blank photometry.

[0031] In the fourth cycle (cycle C4), the control unit 24 controls the first dispensing mechanism 8 to dispense the sample and reagent into the reaction vessel 2 at the first position, and then rotates the incubator 1. As the incubator 1 rotates, a first reaction solution measurement (MP1) is performed at the first position, and a second blank measurement (BK2) is performed at the second position. In this cycle, blank photometry is also performed at the other vessel holding positions where no reaction vessel 2 is held, and the measurement values ​​at the first and second positions are corrected based on the measurement values ​​obtained by these blank photometry.

[0032] In this specification, reaction solution measurement refers to measurement of the light intensity performed when a reaction container 2 is placed in the container holding position and there is reaction solution in the reaction container 2, and this measurement is performed, for example, 60 times in total. In this embodiment, one cycle takes 10 seconds, so that absorbance measurement for a reaction container obtained from one sample is completed in 10 minutes. However, the number of reaction solution measurements and the time required for one cycle are not limited to these and will vary depending on the number of container holding positions.

[0033] Then, in the nth cycle (cycle Cn), the control unit 24 controls the transport mechanism 17 to move the used reaction vessel 2 from the first position in the transport position, discard it in the waste box 21, and then rotate the incubator 1. As the incubator 1 rotates, blank photometry is performed at the first position, and the 59th reaction solution measurement (MP59) is performed at the second position. The blank photometry measurement value at the first position is used to correct the measurement values ​​for this cycle at the second position and other vessel holding positions.

[0034] In the n+1th cycle (cycle Cn+1), the control unit 24 controls the transport mechanism 17 to move a new, unused reaction vessel 2 from the reaction vessel tray 20 and place it in the first position in the transport position, and then rotates the incubator 1. As the incubator 1 rotates, a first blank measurement (BK1) is performed at the first position, and a 60th reaction solution measurement (MP60) is performed at the second position. In this cycle, there is no vessel holding position where blank photometry is performed, so the measurement value of blank photometry in another cycle is used to correct the measurement value of this cycle.

[0035] For example, the measurement value of the first blank measurement (BK1) at the first position of this cycle is corrected using the measurement value of the blank measurement at the first position in the immediately preceding nth cycle, the measurement value of blank photometry at the second position in the immediately following n+2th cycle, or the intermediate value between these measurement values. Similarly, the measurement value of the 60th reaction solution measurement (MP60) at the second position of this cycle is corrected using the measurement value of the blank measurement at the first position in the immediately preceding nth cycle, the measurement value of blank photometry at the second position in the immediately following n+2th cycle, or the intermediate value between these measurement values. Note that, to correct the measurement value in a cycle without blank measurement (no blank photometry), values ​​obtained by linear interpolation may be used, including not only the measurement value of blank photometry in the most recent cycle (with blank photometry) but also the measurement value of blank photometry in the next closest cycle (with blank photometry). Methods other than linear interpolation may also be used for the interpolation.

[0036] In the (n+2)th cycle (cycle Cn+2), the control unit 24 controls the transport mechanism 17 to move the used reaction vessel 2 from the second position in the transport position and discard it in the waste box 21, and then rotates the incubator 1. As the incubator 1 rotates, a second blank measurement (BK2) is performed at the first position, and blank photometry is performed at the second position. In this cycle, the blank photometry measurement value at the second position is used to correct the measurement values ​​in this cycle at the first position and other vessel holding positions. Furthermore, the blank photometry measurement value at the second position in this cycle is used to correct the measurement values ​​in the immediately preceding (n+1)th cycle and the immediately following (n+3)th cycle.

[0037] Here, we will explain the calculation method for correcting the light intensity and absorbance. Note that we will not explain how to correct the blank light intensity measured when the reaction vessel is empty to the blank light intensity when water is present.

[0038] First, the amount of light obtained in the blank measurement immediately after a certain reaction vessel 2 is held in the incubator 1 is I ０ The light amount (empty Pos light amount) obtained by blank photometry performed at another container holding position in the same cycle as the blank measurement is defined as S ０ In addition, the amount of light obtained in the X-th reaction solution measurement of the reaction vessel 2 is expressed as I ｘ The light intensity (empty Pos light intensity) obtained by blank photometry performed at another container holding position in the same cycle as the reaction solution measurement is defined as S ｘ Let's say.

[0039] Then, the corrected light intensity I' of the Xth reaction solution measurement of the reaction vessel 2 is ｘ can be expressed by the following (Equation 1).

[0040]

[0041] Furthermore, the absorbance obtained in the Xth reaction solution measurement of the reaction vessel 2 is A ｘ Then, the corrected absorbance A' of the X-th reaction solution measurement of the reaction vessel 2 is ｘ can be expressed by the following (Equation 2) or (Equation 3).

[0042]

[0043]

[0044] Figure 6 is a graph showing the trends in the light intensity obtained by reaction solution measurement, the light intensity obtained by blank photometry, and the light intensity after correction for reaction solution measurement. As shown in Figure 6, reaction solution measurement is performed once every cycle, while blank photometry is performed once every two cycles. It can also be seen that the light intensity obtained by blank photometry (see ■ in Figure 6) fluctuates (increases) as the number of reaction solution measurements increases, i.e., as time (cycles) passes. This is because the light emission intensity of the light source does not stabilize for a certain period of time after the automatic analyzer is turned on. As a result, the measured values ​​of reaction solution measurement (see ● in Figure 6) are affected by fluctuations in the light emission intensity, and fluctuate (increase), as shown in Figure 6.

[0045] Therefore, in this embodiment, the measurement value of the reaction solution measurement is corrected using the measurement value of the blank photometry. As a result, it can be seen that the light intensity after the correction of the reaction solution measurement (see ▲ in Figure 6) is a relatively stable value even if the light emission intensity fluctuates. In other words, even in a situation where the light emission intensity from the light source is prone to fluctuate, it is possible to measure the reaction solution while suppressing the influence of fluctuations in the light emission intensity without waiting until the light emission intensity stabilizes, thereby improving the reliability of the automatic analyzer.

[0046] In particular, when an LED is used as the light source 101, it is more susceptible to the temperature of the environment in which the automatic analyzer is installed than a halogen lamp, and the amount of light emitted is more likely to fluctuate. However, by correcting the measurement value as in this embodiment, it is possible to suppress a decrease in reliability.

[0047] As described above, the automated analyzer of this embodiment uses disposable reaction vessels 2, and performs photometry by taking advantage of the state of an empty container holding position, which occurs between the time a used reaction vessel 2 is discarded and the time a new reaction vessel 2 is installed, and performs correction based on this value. Therefore, even if the space between adjacent container holding positions is covered with a light-shielding material and it is difficult to provide an optical path dedicated to empty photometry in the incubator 1 itself, empty photometry is possible, and the accuracy of the analysis results can be maintained. Furthermore, by not providing an optical path dedicated to empty photometry in the incubator 1 itself, it is possible to prevent the device from becoming larger and the processing capacity from decreasing.

[0048] The present invention is not limited to the above-described embodiment, and various modifications are possible.

[0049] For example, in the above-described embodiment, blank photometry was performed once every two cycles except immediately after start, but this is not limited to this. The number of cycles in which blank photometry is performed, i.e., the number of cycles in which a reaction vessel 2 is installed or discarded, varies depending on the processing capacity of the automatic analyzer. The number of vessel holding positions in the incubator 1 for biochemistry was 32 in the above-described embodiment, but may be different depending on the processing capacity of the automatic analyzer, etc.

[0050] Although the processing capacity of the automatic analyzer may be reduced compared to the above-described embodiment, the accuracy of the correction may be improved by always performing blank photometry once per cycle. In this case, the control unit controls the operation of each mechanism while scheduling so that a reaction vessel 2 is not held in at least one position of the vessel holder.

[0051] 1...incubator, 2...reaction vessel, 3...common disc for reagent and specimen, 4...reagent bottle, 5...specimen vessel, 6...reagent suction position, 7...specimen suction position, 8...first aliquot mechanism, 9...second aliquot mechanism, 10...pump for first aliquot mechanism, 11...pump for second aliquot mechanism, 12...first aliquot nozzle washing tank, 13...second aliquot nozzle washing tank, 15...spectrophotometer, 16...detection mechanism, 17...transport mechanism, 18...aliquot Dispensing tip, 19...dispensing tip tray, 20...reaction vessel tray, 21...disposal box, 22...dispensing tip mounting position, 23...dispensing tip disposal position, 24...controller, 62...vessel insertion hole, 63...incident side slit, 64...exit side slit, 101...light source, 102...condensing lens, 103...illumination slit, 104...reaction liquid, 105...receiving slit, 106...concave diffraction grating, 107...light receiver.

Claims

1. a container holding unit capable of holding a plurality of containers for containing a reaction liquid generated by mixing a sample and a reagent; A light source that irradiates light; a light receiver that receives light emitted by the light source; A control unit that performs a measurement related to light from the signal output by the optical receiver, the container is a disposable container, The light source is In a first photometry cycle, light is irradiated in a state where the container is held at a first position of the container holder and the container is not held at a second position of the container holder; In a second photometry cycle, light is irradiated in a state in which the container is not held at the first position of the container holder and the container is held at the second position of the container holder; The control unit is correcting a measurement value associated with the light irradiated to the first position in the first photometry cycle based on a measurement value associated with the light irradiated to the second position in the first photometry cycle; an automatic analyzer that corrects a measurement value relating to light irradiated to the second position in the second photometry cycle based on a measurement value relating to light irradiated to the first position in the second photometry cycle.

2. (delete)

3. 2. The automated analyzer according to claim 1, a conveying mechanism for moving the container before use to the container holding section and for moving the container after use from the container holding section; In a cycle immediately following the first photometry cycle, the transport mechanism moves the container before use to the second position; In the cycle immediately following the second photometric cycle, the transport mechanism moves the container before use to the first position.

4. The automatic analyzer according to claim 3, In the first photometry cycle, after the transport mechanism moves the used container from the second position, the container holder rotates and is irradiated with light; In the second photometry cycle, after the transport mechanism moves the used container from the first position, the container holding portion rotates and light is irradiated.

5. 2. The automated analyzer according to claim 1, In a cycle with empty photometry, the light source irradiates light in a state where the container is not held at any position of the container holder, In a cycle without empty photometry, the light source irradiates light in a state where the container is held at any position of the container holder, The control unit corrects the measurement value relating to light irradiated to a specified position in the cycle without empty photometry based on the measurement value relating to light irradiated to a position where the container is not held in the most recent cycle with empty photometry.

6. 2. The automated analyzer according to claim 1, The control unit corrects the measurement value relating to light irradiated at a specific position where the container is held based on the average value of the measurement values ​​relating to light irradiated at multiple positions where the container is not held.

7. 2. The automated analyzer according to claim 1, The control unit of the automatic analyzer corrects the measurement value relating to light irradiated to a predetermined position where the container is held based on the measurement value relating to light at a position among a plurality of positions where the container is not held, the position whose irradiation timing is closest to the predetermined position.

8. 2. The automated analyzer according to claim 1, The control unit controls the container holder so that the container is not held in at least one position of the container holder.

9. 2. The automated analyzer according to claim 1, The container holder is made of a light-shielding material, and the containers are inserted into a plurality of holes provided at predetermined intervals.