Patent Description:
The automatic analyzer is a device that automatically analyzes a sample such as blood or urine. As an immunoanalytical method for the detection unit of an automatic analyzer, the method in which a reaction liquid containing a sample is introduced into a flow cell and emitted light is detected by a light detector is known. This type of detection method that uses a flow cell is disclosed, for example, in Patent Literature <NUM>.

Generally, the flow cell loaded in a conventional detection unit is fixed on the board using screws to prevent it from being out of alignment with a photomultiplier tube. By fixing the flow cell on the board using screws in this way, the light blocking effect for the area surrounded by the flow path in the flow cell and the photomultiplier tube is improved, thereby suppressing the decline in the S/N ratio at the time of signal measurement by the photomultiplier tube.

However, when the flow cell is fixed on the board with screws, it is necessary to install or remove the screws each time the flow cell is loaded or unloaded. This results in a low working efficiency.

The object of the present invention is to provide an automatic analyzer that improves the working efficiency in loading or unloading a flow cell.

The above cited object is achieved by an automatic analyzer as defined in claim <NUM> and in claim <NUM>, respectively.

According to the present disclosure, it is possible to provide an automatic analyzer that improves the working efficiency in loading or unloading a flow cell.

Hereinafter, an embodiment of the present invention will be described referring to drawings.

First, the general configuration of an automatic analyzer will be described referring to <FIG> is a plan view of the automatic analyzer.

The automatic analyzer <NUM> includes a rack <NUM>, a rack transport line <NUM>, a sample dispensing mechanism <NUM>, an incubator (reaction disk) <NUM>, a storage unit <NUM>, a transport mechanism <NUM>, a reaction container stirring mechanism <NUM>, a disposal hole <NUM>, a reagent disk <NUM>, a reagent dispensing mechanism <NUM>, a reaction liquid aspiration nozzle <NUM>, a detection unit <NUM>, and a control unit (not shown).

A sample container <NUM> that contains a sample is set in the rack <NUM>.

The rack transport line <NUM> moves the sample container <NUM> set in the rack <NUM> to a sample dispensing position near the sample dispensing mechanism <NUM>.

The sample dispensing mechanism <NUM> has an arm that rotates and moves up and down and a nozzle that aspirates and discharges the sample. A sample dispensing tip can be attached to or detached from the tip of the nozzle. The sample dispensing mechanism <NUM> moves its nozzle down to the sample container <NUM> at the sample dispensing position and aspirates a prescribed amount of sample, then rotates the arm to discharge the sample into a reaction container <NUM> at a prescribed position over the incubator <NUM>.

In the incubator <NUM>, a plurality of container holding holes in which a plurality of reaction containers <NUM> can be set are formed in a circumferential direction. The incubator <NUM> rotates to move each reaction container <NUM> to prescribed positions such as a reaction container set position, a reagent discharge position, a sample discharge position, and a reaction container disposal position.

A plurality of reaction containers <NUM> and sample dispensing tips that are unused are set in the storage unit <NUM>.

The transport mechanism <NUM> can move in three directions, namely X axis, Y axis and Z axis directions, and transports the reaction container <NUM> and sample dispensing tip. For example, the transport mechanism <NUM> transports an unused reaction container <NUM> to a container holding hole at a prescribed position of the incubator <NUM> and transports an unused sample dispensing tip to a sample dispensing tip mounting position <NUM>. Also, for example, the transport mechanism <NUM> transports the reaction container <NUM> to a reaction container stirring mechanism <NUM> and transports the reaction container <NUM> and sample dispensing tip that have been used, to a disposal hole <NUM>.

The reaction container stirring mechanism <NUM> is a mechanism that mixes the sample in the reaction container <NUM> taken out of the incubator <NUM> and a reagent.

The disposal hole <NUM> is a hole to dispose of the container <NUM> and sample dispensing tip that have been used.

A plurality of reagent containers <NUM> are set in the reagent disk <NUM>. A reagent disk cover <NUM> is provided over the reagent disk <NUM> and the inside of the reagent disk <NUM> is kept at a prescribed temperature. An opening portion is formed in part of the reagent disk cover <NUM>.

The reagent dispensing mechanism <NUM> has an arm that rotates and moves up and down and a nozzle that aspirates and discharges a reagent. The reagent dispensing mechanism <NUM> immerses the tip of the nozzle in the reagent in the reagent container <NUM> to aspirate the reagent and discharges the aspirated reagent into the reaction container <NUM>.

The reaction liquid aspiration nozzle <NUM> rotates and moves up and down to aspirate the reaction liquid mixed in the reaction container <NUM> on the incubator <NUM> and send it to the detection unit <NUM>.

The detection unit <NUM> detects a specific component contained in the reaction liquid aspirated by the reaction liquid aspiration nozzle <NUM>.

The control unit (not shown) controls operation of the whole automatic analyzer <NUM>. The control unit receives input from an operator and outputs a control signal to various mechanisms and so on to control their operation.

Next, an explanation will be given of operation of the automatic analyzer <NUM>.

First, the transport mechanism <NUM> moves to above the storage unit <NUM>, then moves down, grips an unused reaction container <NUM> and moves up. After that, the transport mechanism <NUM> moves to above a prescribed position of the incubator <NUM>, then moves down and sets the reaction container <NUM> in a container holding hole. Again, the transport mechanism <NUM> moves to above the storage unit <NUM>, moves down, grips an unused sample dispensing tip and moves up. After that, the transport mechanism <NUM> moves to above the sample dispensing tip mounting position <NUM> and moves down to set the sample dispensing tip at the sample dispensing tip mounting position <NUM>. Then, the sample dispensing mechanism <NUM> moves to above the sample dispensing tip mounting position <NUM>, then moves down and presses the sample dispensing tip into the tip of the nozzle to mount it there.

The reagent dispensing mechanism <NUM> rotates and moves to above the opening portion of the reagent disk cover <NUM>, then moves down, immerses the tip of the nozzle in the reagent in the reagent container <NUM> and aspirates a prescribed amount of reagent. Then, the reagent dispensing mechanism <NUM> moves up and rotates and moves to above a prescribed position of the incubator <NUM>, and moves down to discharge the reagent into the reaction container <NUM>.

Also, the sample dispensing mechanism <NUM> with the sample dispensing tip mounted thereon rotates and moves to above the sample container <NUM> placed in the rack <NUM>, then moves down and aspirates a prescribed amount of sample in the sample container <NUM>. After that, the sample dispensing mechanism <NUM> rotates and moves to the sample discharge position of the incubator <NUM>, then moves down and discharges the sample into the reaction container <NUM> into which the reagent has been dispensed. After that, the sample dispensing mechanism <NUM> rotates and moves to above the disposal hole <NUM> and disposes of the used sample dispensing tip into the disposal hole <NUM>.

After that, the reaction container <NUM> into which the sample and reagent have been discharged is moved to a prescribed position by rotation of the incubator <NUM> and transported to the reaction container stirring mechanism <NUM> by the transport mechanism <NUM>. The reaction container stirring mechanism <NUM> stirs and mixes the sample and reagent by applying rotating motion to the reaction container <NUM>. After that, the reaction container <NUM> is moved back to the prescribed position of the incubator <NUM> by the transport mechanism <NUM>.

Next, when a given reaction time has elapsed at the prescribed position, the reaction liquid aspiration nozzle <NUM> moves to above the reaction container <NUM>, then moves down and aspirates the reaction liquid in the reaction container <NUM>. The reaction liquid aspirated by the reaction liquid aspiration nozzle <NUM> is analyzed by the detection unit <NUM>.

Hereinafter, the configuration of the detection unit <NUM> will be described referring to <FIG>. In the immunoanalytical field, a fluorescence method, chemiluminescence method and electrochemiluminescence method are used as analysis methods for measuring the presence and concentration of an extremely small amount of the object of measurement in the reaction liquid (<NUM>-<NUM> mol or less). For this embodiment, an explanation is given of an example of using the electrochemiluminescence method in which the light emitted from the reaction liquid is detected when a voltage is applied to the reaction liquid.

In the electrochemiluminescence method, a luminescent reagent is bound to the object of measurement such as a hormone by antigen-antibody reaction to determine the quantity of emitted light derived from the luminescent reagent. The measurement is performed while the reaction liquid is made to flow in the flow cell.

The detection unit <NUM> includes: a flow cell <NUM> into which the reaction liquid is introduced; a magnetic trap means that captures the magnetic particles contained in the reaction liquid; and a photomultiplier tube <NUM> that detects the light generated in the flow cell <NUM>.

As shown in <FIG>, the flow path inlet side of the flow cell <NUM> is connected to the reaction liquid aspiration nozzle <NUM> through a piping <NUM> and its flow path outlet side is connected to a syringe <NUM> that generates a pressure difference to aspirate the reaction liquid, etc. and a drain <NUM> to discharge the reaction liquid, etc. The flow path outlet side of the flow cell <NUM> is bifurcated midway by a flow path switching valve <NUM>, into one path extending to the syringe <NUM> and the other path extending to the drain <NUM>. The flow cell <NUM> is housed in a case <NUM> located under the photomultiplier tube <NUM> and fixed on a cell frame <NUM>.

The magnetic trap means includes a magnet for capturing magnetic particles <NUM>, a magnet arm <NUM>, and a magnet drive motor <NUM>. By driving the magnet drive motor <NUM>, the magnetic trap means rotates the magnet arm <NUM> to change the position of the magnet for capturing magnetic particles <NUM> to an operating position (position near the flow cell <NUM>) or an escape position (position remoter from the flow cell <NUM>).

The photomultiplier tube <NUM> is a light detector that is disposed above the flow cell <NUM>. The flow cell <NUM> is connected to a voltage applying means (not shown). As a voltage is applied by the voltage applying means, a luminous phenomenon occurs in the magnetic particles captured in the flow cell <NUM>. The photomultiplier tube <NUM> measures the intensity of light generated in the flow cell <NUM>.

Next, an explanation will be given of the method for measuring the light intensity in the detection unit <NUM>.

First, with the reaction liquid aspiration nozzle <NUM> immersed in the reaction liquid in the reaction container <NUM>, the flow path switching valve <NUM> is switched so that the flow path on the drain <NUM> side is closed and the flow path on the flow cell <NUM> side is open. Then, the syringe <NUM> is activated toward the aspiration side to aspirate the reaction liquid in the reaction container <NUM>, and the reaction liquid in the reaction container <NUM> passes through the piping <NUM> and flows into the flow cell <NUM>. The reaction liquid is a mixture of the sample containing the object of measurement and the reagent (reagent containing a luminescent label, and a reagent containing magnetic particles), which forms an immune complex.

At this time, the magnet drive motor <NUM> is driven to rotate the magnet arm <NUM><NUM> degrees, so the magnet for capturing magnetic particles <NUM> at the tip of the magnet arm <NUM> comes to just below the flow cell <NUM> (moves to the operating position). Consequently, the magnetic particles in the reaction liquid passing through the flow cell <NUM> are magnetically captured by the flow cell <NUM>.

After that, the reaction liquid aspiration nozzle <NUM> moves to a container that contains an auxiliary liquid for luminescent reaction and with the nozzle <NUM> immersed in the auxiliary liquid for luminescent reaction, the syringe <NUM> is activated toward the aspiration side. Consequently, the auxiliary liquid for luminescent reaction flows into the flow cell <NUM> and while the immune complex remains magnetically captured, the residual reaction liquid in the flow cell <NUM> is substituted by the auxiliary liquid for luminescent reaction.

Then, after the syringe <NUM> stops moving, the magnet drive motor <NUM> is driven in the opposite direction and the magnet arm <NUM> rotates backward <NUM> degrees, so the magnet for capturing magnetic particles <NUM> moves away from the flow cell <NUM> (moves to the escape position).

Then, the photomultiplier tube <NUM> measures the dark current output signal in the flow cell <NUM> through a light transmission window formed in the upper surface of the flow cell <NUM>. After that, a voltage is applied to the inside of the flow cell <NUM> by the voltage applying means so that electrochemical luminescent reaction of the luminescent label contained in the immune complex is induced. At this time, the photomultiplier tube <NUM> measures the light intensity through the light transmission window and determines the quantity of the object of measurement contained in the immune complex.

After measurement of the light intensity, the reaction liquid aspiration nozzle <NUM> moves to a container containing a cleaning liquid and with the nozzle <NUM> immersed in the cleaning liquid, the syringe <NUM> is activated toward the aspiration side. Consequently, the cleaning liquid flows into the piping <NUM> and flow cell <NUM>, and the reaction liquid and auxiliary liquid for luminescent reaction that are remaining in the piping <NUM> and flow cell <NUM> are removed to clean the piping <NUM> and flow cell <NUM>.

Lastly, the flow path switching valve <NUM> is switched to close the flow path on the flow cell <NUM> side and open the flow path on the drain <NUM> side. Then, the syringe is activated toward the discharge side, and the reaction liquid, auxiliary liquid for luminescent reaction and cleaning liquid that are remaining in the syringe <NUM> are discharged into the drain <NUM>.

By carrying out the above steps repeatedly, analysis is made on a plurality of samples for a plurality of analysis items.

<FIG> is a perspective view showing the appearance of the detection unit <NUM>. The detection unit <NUM> incorporates the flow cell <NUM>, photomultiplier tube <NUM> and so on. In an immune assay based on the electrochemiluminescence method, the photomultiplier tube <NUM> receives the very weak light generated by luminescent reaction of the luminescent label contained in the immune complex in the flow cell <NUM> under a low noise condition, and picks it up as an electric signal. Therefore, in order to block the external light as a main reason for the decline in the S/N ratio at the time of signal measurement by the photomultiplier tube <NUM>, the housing <NUM> of the detection unit <NUM> and the lid <NUM> are made of a light-blocking material and has a hermetically sealed structure.

The lid <NUM> is connected to the housing <NUM> by hinges <NUM>, and tightening jigs <NUM> that fix the lid <NUM> in the closed state are provided as position fixing members on the lid <NUM>. Therefore, when opening or closing the lid <NUM>, work for installing and removing screws is not needed, so loading and unloading of the flow cell <NUM> can be carried out easily in a short time.

In addition, a sealing member is provided all along the peripheral edge of the opening portion <NUM> of the housing <NUM>, namely the front end of the side wall of the housing <NUM>. The material of the sealing member is not limited as far as it is a material that has cushioning and heat-insulating properties, such as black soft rubber or soft polyurethane. The sealing member may be located on the back side of the lid <NUM> and at a position facing the front end of the side wall of the housing <NUM>. Since the detection unit <NUM> has a sealing member like this, the sealability is improved and thus penetration of external light or temperature change due to inflow of external air can be prevented.

The tightening jig <NUM> may be another type of fixing member such as a hook, as far as it can press the lid <NUM> against the sealing member between the housing <NUM> and lid <NUM> to fix the position of the lid <NUM>. Also, the tightening jig <NUM> may be located in the housing <NUM> so that its position changes with respect to the lid <NUM> from the housing <NUM> side for locking. However, if it is structured to fix the lid <NUM> in the closed state by a magnetic force, an immune assay may be given by an immunoanalytical electrochemiluminescence method based on the electrochemiluminescence method that uses the magnetic trap means and photomultiplier tube <NUM>. For this reason, it is desirable that the fixing member should be made of a non-magnetic material and configured to tighten the lid <NUM> and housing <NUM> mechanically.

<FIG> is a perspective view showing the internal structure of the detection unit <NUM> in a state in which the flow cell <NUM> is mounted. As shown in <FIG>, the detection unit <NUM> includes a photomultiplier tube <NUM>, a board <NUM> disposed vertically below the photomultiplier tube <NUM>, and a flow cell <NUM> disposed vertically below the board. In addition, the lower surface of the flow cell <NUM> is pressed vertically upward from below by a pressing member <NUM>, so the flow cell <NUM> and photomultiplier tube <NUM> closely contact each other, thereby improving the light blocking effect in the area surrounded by the flow path in the flow cell <NUM> and the photomultiplier tube <NUM>. Particularly, the pressing member <NUM> presses the flow cell <NUM> at several spots, so the sealability of the flow cell <NUM> and the photomultiplier tube <NUM> is further improved. Since the flow cell <NUM> is fixed on the board <NUM> by the pressing member <NUM>, the flow cell <NUM> can be loaded and unloaded more easily than when screws or the like are used to fix it.

<FIG> is a cross-sectional perspective view of the flow cell <NUM>. As shown in <FIG>, on the upper surface of the flow cell <NUM>, a recess portion 209a is formed in a circular shape on the inner circumferential side and a protrusion portion 209b is formed in a circumferential shape on its outer circumferential side. Two positioning holes are formed on the outer circumferential side of the protrusion portion 209b of the flow cell <NUM> at specific positions in the circumferential direction.

<FIG> is a perspective view of the internal structure of the detection unit <NUM>, showing a state before the flow cell <NUM> is loaded. As shown in <FIG>, on the lower surface of the board <NUM>, a protrusion portion <NUM> is formed in a circular shape on the inner circumferential side and a recess portion <NUM> is formed in a circumferential shape on its outer circumferential side. In addition, on the lower surface of the board <NUM>, a positioning pin <NUM> that extends vertically downward from a specific position in the circumferential direction is provided outside the recess portion <NUM>. The positioning pin <NUM> is disposed at two symmetrical positions with respect to the center of the protrusion portion <NUM>.

When attaching the flow cell <NUM> to the board <NUM>, first the recess portion 209a of the flow cell <NUM> is fitted to the protrusion portion <NUM> of the board <NUM> and the protrusion portion 209b of the flow cell <NUM> is fitted to the recess portion <NUM> of the board <NUM>. Then, the positioning holes of the flow cell <NUM> are inserted to the positioning pins <NUM> of the board <NUM> to fix the position of the flow cell <NUM> with respect to the board <NUM>. After that, as shown in <FIG>, a plurality of pressing members <NUM> are pressed against the lower surface of the flow cell <NUM> so that the flow cell <NUM> is fixed on the board <NUM> in axial alignment with the photomultiplier tube <NUM>.

<FIG> is a front view showing the configuration of an interlocking mechanism <NUM> that interlocks operations of the two (left and right) pressing members <NUM>. The interlocking mechanism <NUM> includes an operation knob <NUM>, a connecting plate <NUM>, and an arm <NUM>. As the operator holds and slides the operation knob <NUM> horizontally in a prescribed direction, the pressing members <NUM> are moved simultaneously and symmetrically through the connecting plate <NUM> and arm <NUM> and the two pressing members <NUM> press the flow cell <NUM> simultaneously. Since the two pressing members <NUM> can be pressed or released simply by moving the operation knob <NUM>, it is easy to load or unload the flow cell <NUM>.

The pressing member <NUM> has a pressing portion on the upper surface of its tip and the pressing portion presses the lower surface of the flow cell <NUM>. In order to suppress scratching called chipping on the flow cell <NUM> when it is pressed, it is desirable that the pressing member <NUM> should be made of a material excellent in abrasion resistance and slidability, as typified by polyacetal resin. For the pressing force of the pressing member <NUM>, the spring force of a pressing pressure spring <NUM> attached to a SUS shaft <NUM> that connects the arm <NUM> and pressing member <NUM> is used.

Next, how the pressing member <NUM> locks the flow cell <NUM> will be concretely explained.

<FIG> is a plan view showing a state in which the two (left and right) pressing members <NUM> press the flow cell <NUM> simultaneously. <FIG> shows a state in which the pressing members <NUM> are in the escape state, <FIG> shows a state in which the pressing members <NUM> are moving for locking, and <FIG> shows a state in which locking motion by the pressing members <NUM> is completed.

<FIG> is a perspective view showing a state in which the two (left and right) pressing members <NUM> press the flow cell <NUM> simultaneously, as viewed from below. <FIG> shows a state in which the pressing members <NUM> are in the escape state, <FIG> shows a state in which the pressing members <NUM> are moving for locking, and <FIG> shows a state in which locking motion by the pressing members <NUM> is completed.

First, when the pressing members <NUM> are in the escape state as shown in <FIG> and <FIG>, the flow cell <NUM> is attached from below the board <NUM> with the recess and protrusion portions fitted to each other on the contact surface, and the positioning pins <NUM> are inserted into the positioning holes of the flow cell <NUM>.

Then, as the operation knob <NUM> is slid to the right, the process proceeds from the state as shown in <FIG> and <FIG> in which the movement for locking is under way, to the state as shown in <FIG> and <FIG> in which the lower surface of the flow cell <NUM> is pressed by the two pressing members <NUM> to lock the flow cell <NUM> completely. As the operation knob <NUM> is slid to the right horizontally, the pressing spring <NUM> pushes up the pressing member <NUM>. At this time, the left pressing member <NUM> presses the left side with respect to the center of the flow cell <NUM> and the right pressing member <NUM> presses the right side with respect to the center of the flow cell <NUM>. This suppresses the imbalance between the left and right pressing forces on the flow cell <NUM>, thereby improving the light blocking effect for the area surrounded by the flow path in the flow cell <NUM> and the photomultiplier tube <NUM>. Furthermore, since the left and right pressing members <NUM> press the flow cell <NUM> simultaneously, the imbalance between the pressing forces is suppressed and a positioning error is prevented, thereby contributing to improvement in the light blocking effect.

As explained above, according to this embodiment, the flow cell <NUM> can be loaded and unloaded without using screws and without taking out the board <NUM>.

Next, a variation of the embodiment will be described referring to <FIG> and <FIG>. In the variation, guide members <NUM> that guide the positioning hole of the flow cell <NUM> to the position of the positioning pin <NUM> of the board <NUM> are provided on the left and right of the detection unit <NUM>. These guide members <NUM> are curved horizontally along the outer shape of the flow cell <NUM> to facilitate positioning of the flow cell <NUM>.

Next, how pressing members <NUM> according to the variation lock the flow cell <NUM> will be concretely explained.

<FIG> is a plan view showing a state in which the two (front and rear) pressing members <NUM> (leaf springs <NUM>) press the flow cell <NUM> simultaneously. <FIG> (<NUM>) shows a state in which the pressing members <NUM> are in the escape state and <FIG> shows a state in which locking motion by the pressing members <NUM> is completed.

<FIG> is a perspective view showing a state in which the front and rear pressing members <NUM> press the flow cell <NUM> simultaneously as viewed from below, and a front view of the pressing members <NUM> as viewed from the front. <FIG>(<NUM>-a) and <FIG>(<NUM>-b) show a state in which the pressing members <NUM> are in the escape state, <FIG>(<NUM>-a) and <FIG>(<NUM>-b) show a state in which the pressing members <NUM> are moving for locking, and <FIG>(<NUM>-a) and <FIG>(<NUM>-b) show a state in which locking motion by the pressing members <NUM> is completed.

First, in the escape state as shown in <FIG>, <FIG>(<NUM>-a) and <FIG>(<NUM>-b), the flow cell <NUM> is inserted from the front side of the board <NUM> below the board <NUM> along the guide members <NUM> and the positioning pin <NUM> of the board <NUM> is inserted into the positioning hole of the flow cell <NUM>. Since the guide member <NUM> is to be in contact with the flow cell <NUM>, in order to prevent chipping it is desirable that it should be made of a material excellent in abrasion resistance and slidabililty, as typified by polyacetal.

After that, as an operation lever <NUM> of the interlocking mechanism to interlock the movements of the two (front and rear) pressing members <NUM> is rotated, the process proceeds from the state as shown in <FIG>(<NUM>-a) and <FIG>(<NUM>-b) in which movement for locking is under way, to the state as shown in <FIG>, <FIG>(<NUM>-a) and <FIG>(<NUM>-b) in which the lower surface of the flow cell <NUM> is pressed by the two pressing members <NUM> to lock the flow cell <NUM> completely. Furthermore, if it is known in advance that the flow cell <NUM> will remain loaded for a long time, it can be fixed more stably by fixing it at a fixed position <NUM> using a screw after completion of its locking, as shown in <FIG> (<NUM>-a).

Here, the operation lever <NUM> is connected to the front leaf spring <NUM> through a rotating shaft <NUM> and the front leaf spring <NUM> and the rear leaf spring <NUM> are connected by a bearing portion <NUM>, so the front and rear pressing members <NUM> are moved simultaneously by rotation of the operation lever <NUM>. The spring force of the leaf spring <NUM> is used for the pressing force of the pressing member <NUM>. Since the pressing member <NUM> is to be in contact with the flow cell <NUM>, in order to prevent chipping it is desirable that it should be made of a material excellent in abrasion resistance and slidabililty, as typified by polyacetal.

According to the variation, the front pressing member <NUM> presses the front side with respect to the center of the flow cell <NUM> and the rear pressing member <NUM> presses the rear side with respect to the center of the flow cell <NUM>. This suppresses the imbalance between the front and rear pressing forces, thereby improving the light blocking effect for the area surrounded by the flow path in the flow cell <NUM> and the photomultiplier tube <NUM>. Furthermore, since the front and rear pressing members <NUM> press the flow cell <NUM> simultaneously, the imbalance between the pressing forces is suppressed and a positioning error is prevented, thereby contributing to improvement in the light blocking effect.

Claim 1:
An automatic analyzer (<NUM>), comprising:
a photomultiplier tube (<NUM>);
a board (<NUM>) disposed vertically below the photomultiplier tube (<NUM>); and
a flow cell (<NUM>) disposed vertically below the board (<NUM>), wherein
a lower surface of the board (<NUM>) has a protrusion portion (<NUM>) and/or a recess portion (<NUM>), and an upper surface of the flow cell (<NUM>) has a recess portion (209a) and/or a protrusion portion (209b),
characterized in that
the automatic analyzer (<NUM>) comprises a plurality of pressing members (<NUM>) configured to press the flow cell (<NUM>) vertically upward from below in a state in which the recess portion (209a) and/or the protrusion portion (209b) of the flow cell (<NUM>) is fitted to the protrusion portion (<NUM>) and/or the recess portion (<NUM>) of the board (<NUM>) and an interlocking mechanism (<NUM>) configured to interlock operations of the plurality of pressing members (<NUM>), wherein the plurality of pressing members (<NUM>) are configured to simultaneously press the flow cell (<NUM>) by the interlocking mechanism (<NUM>).