JP6683980B1 - Microplate reader - Google Patents

Abstract

Disclosed is a microplate reader that can be miniaturized and can perform optical measurement of all samples contained in each well of a microplate with high accuracy. The microplate reader is arranged on one side of the microplate and on the opposite side of the light projecting section and the light receiving section with the microplate sandwiched between the light projecting section and the light receiving section. The light passing through the sample contained in the well is reflected between the light projecting section and the light receiving section, and the light passing through the sample which is arranged between the light projecting section and the light receiving section and reflected by the reflecting member. A light guide section having a plurality of sets of light receiving light guide paths for guiding light to the light receiving section, and a plurality of light receiving light guide paths are surrounded by an enclosing member made of a pigment-containing resin containing a pigment having a property of absorbing light. And a limiting unit that limits the angle component of the light incident on the light receiving unit.

Description

  The present invention relates to a microplate reader for performing optical measurement on a sample contained in a well of a microplate.

Conventionally, for example, reagent separation, synthesis, extraction, analysis, and cell culture have been performed using a flat plate-shaped microplate made of acrylic, polyethylene, polystyrene, glass, etc. and provided with a large number of wells. There is. For example, the measurement of an antibody-antigen reaction (enzyme immunoreaction) generated by injecting a reagent containing an antigen into each well in which an antibody is immobilized (for example, measurement by ELISA (Enzyme-Linked Immuno Sorbent Assay) method) It is performed using a plate.
For the sample contained in each well of the microplate, for example, the optical property of the sample is measured. This measurement is performed by a microplate reader, which is a measurement device that performs optical measurement on the sample. The microplate reader can measure optical properties such as absorption, fluorescence, chemiluminescence, and fluorescence polarization.

  As a conventional microplate reader, for example, there is a technique described in Patent Document 1 (JP-A-2014-41121). The microplate reader described in Patent Document 1 (Japanese Unexamined Patent Publication No. 2014-41121) is an optical device for irradiating a sample with light or observing light emission from the sample irradiated with light to perform optical measurement. It has a dynamic measuring / detecting device (measuring head). Light irradiation from the measurement head to the microplate is performed from the bottom of each well of the microplate, and the measurement head measures observation light emitted above each well. The measurement head is fixed, and the microplate is arranged in a two-dimensional direction so that the well is positioned on the detection axis of the measurement head (axis perpendicular to the microplate (Z axis)) by the drive mechanism of the microplate reader. Scanning is performed in the (X direction, Y direction).

  Further, Patent Document 2 (Japanese Patent Laid-Open No. 2009-103480) discloses a microplate reader miniaturized to be portable. The microplate reader described in Patent Document 2 (Japanese Unexamined Patent Publication No. 2009-103480) has a space into which eight consecutive microplates in which eight wells are arranged in a row can be inserted, and the microplate is provided in the space. It is configured to be slidable. This microplate reader has a structure in which light is irradiated to the sample held in the well from a position above the space and facing the well upper surface of the microplate. A photodiode for detecting the light emitted from the sample is provided below the space. The microplate reader performs light measurement while sliding the microplate in the space.

JP, 2014-41121, A JP, 2009-103480, A

However, the microplate reader described in Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2014-41121) requires a drive mechanism for scanning the microplate every time one optical measurement is performed, and the device itself is large. Becomes
Therefore, it is difficult to cope with the miniaturization of the device required in the field such as the point of care (POCT) inspection in the field of life science.

  Further, although the microplate reader described in Patent Document 2 (Japanese Patent Laid-Open No. 2009-103480) is small enough to be portable, outside light causes noise in the space in which the microplate is inserted. There is a possibility that the light may enter as light, and the light measurement of the sample contained in each well cannot be performed with high accuracy.

  Therefore, it is an object of the present invention to provide a microplate reader that can be miniaturized and that can perform optical measurement of all samples contained in each well of a microplate with high accuracy.

  In order to solve the above-mentioned problems, one aspect of a microplate reader according to the present invention is arranged on one side of a microplate having a casing and a plurality of wells arranged in the casing. Of the micro plate, a light receiving unit corresponding to one well of the micro plate, and a light receiving unit corresponding to one well of the micro plate; A reflecting member which is arranged on the side opposite to the light receiving part, and which reflects light passing through the sample contained in the well from the light projecting part and the light receiving part to the light projecting part and the light receiving part; A light-receiving light-guiding path that is disposed between the light-projecting unit and the light-receiving unit and that guides the light reflected by the reflecting member and passing through the sample to the light-receiving unit. A plurality of sets of the light projecting unit, the light receiving unit, and the light receiving light guide path corresponding to a shell are provided, and a pigment containing a pigment having a property of absorbing light in the plurality of light receiving light guide paths. It further comprises a light guide section surrounded by an enclosing member made of a resin containing, and a limiting section for limiting an angular component of light incident on the light receiving section.

  As described above, the light projecting portion, the light receiving portion, and the light receiving light guide path are provided corresponding to one well, and a plurality of sets of the light projecting portion, the light receiving portion, and the light receiving light guide path are provided. The light guide unit further includes a plurality of light receiving light guide paths surrounded by a pigment-containing resin capable of absorbing external light and scattered light. Therefore, it is possible to prevent external light, scattered light, and the like from entering the light receiving unit as stray light (noise light). Therefore, a complicated optical system corresponding to multiple scattering of stray light is unnecessary, and the optical system can be downsized. Further, since the limiting unit that limits the angle component of the light incident on the light receiving unit is provided, the measurement error due to the stray light can be appropriately reduced. Therefore, highly accurate measurement is possible.

Further, in the above microplate reader, at least as many sets of the light projecting unit, the light receiving unit, and the light receiving light guide path corresponding to the one well may be provided as the number of wells of the microplate. .
In this case, all the light measurements of the sample contained in each well of the microplate can be performed almost simultaneously, and the measurement time can be shortened. In addition, since a complicated drive mechanism for scanning the microplate as in the related art is not necessary, it is possible to realize miniaturization.

Furthermore, in the above-mentioned microplate reader, the number of sets of the light projecting section, the light receiving section, and the light receiving light guide path corresponding to the one well is less than the number of wells of the microplate, and all of the microplates are included. A movement mechanism for sequentially moving the microplate relative to the set of the light projecting unit, the light receiving unit, and the light receiving light guide path may be provided so as to correspond to the well.
In this case, it is not necessary to provide a set of the light projecting portion, the light receiving portion, and the light receiving light guide path corresponding to all the wells of the microplate, and the size can be greatly reduced. Further, by sequentially moving the microplate relative to the set of the light projecting unit, the light receiving unit, and the light receiving guide path, it is possible to perform all optical measurements of the sample contained in each well of the microplate. It is possible.

In the above microplate reader, a set of the light projecting unit, the light receiving unit, and the light receiving light guide path corresponding to the one well is provided by the number of wells on one side of the microplate. The moving mechanism sequentially moves the microplate relative to the set of the light projecting unit, the light receiving unit, and the light receiving light guide path only in a direction orthogonal to the one side. Good.
In this case, movement by the movement mechanism can be movement in only one axis direction. Therefore, the structure of the moving mechanism can be simplified and the cost can be reduced. Further, since it can be made thin, it can be installed in a limited space such as a culture space in an incubator.

Further, in the above-mentioned microplate reader, at least the number of wells of the microplate corresponding to one well of the microplate on the light-projecting substrate provided with a plurality of the light-projecting portions. And an aperture section that allows light reflected by the reflecting member and passed through the sample to pass through and enter the light-receiving light guide path, wherein the limiting section is a light-incident end of the light-receiving light guide path. The aperture portion may be smaller than the opening.
In this way, by making the aperture portion for making the light reflected by the reflecting member and passing through the sample into the light receiving light guide path smaller than the opening at the light incident end of the light receiving light guide path, It is possible to limit the angular component of the incident light. Therefore, it is possible to limit the angle component of the light incident on the light receiving portion, and it is possible to obtain a highly accurate measurement result.

Further, in the above-mentioned microplate reader, the limiting portion may be the reflecting member selectively provided on a surface facing the microplate, depending on a position where the light receiving light guide path is formed.
In this case, a part of the light that has passed through one well and reached the reflection member is not reflected, and as a result, the angular component of the light that enters the light receiving portion can be limited. That is, it is possible to suppress a part of the light that has reached the reflecting member after passing through one well from entering another well adjacent to the well. Therefore, highly accurate measurement results can be obtained.

Further, in the above microplate reader, the reflecting member is selectively provided on one substrate, and at least a part of a region of the substrate where the reflecting member is not provided is AR-coated. May be. Alternatively, a light absorbing member made of a pigment-containing resin containing a pigment having a property of absorbing light may be provided in at least a part of a region of the substrate where the reflecting member is not provided.
In this case, it is possible to appropriately suppress the occurrence of light reflection in the region where the reflection member is not provided. Therefore, it is possible to prevent the light reflected in the region where the reflecting member is not provided from adversely affecting the measurement result.

Further, in the above microplate reader, the limiting section may be a condenser lens that condenses the light emitted from the light projecting section.
In this case, the spread of the light emitted from the light projecting section can be narrowed by the condenser lens, and as a result, the angular component of the light entering the light receiving section can be limited. That is, it is possible to suppress a part of the light that has reached the reflecting member after passing through one well from entering another well adjacent to the well. Therefore, highly accurate measurement results can be obtained.

Further, in the above microplate reader, the light guide section is arranged above the light receiving section, the light projecting section is arranged above the light guide section, and the micro array is arranged above the light projecting section. The reflecting member may be arranged above the plate.
In this way, the microplate reader arranges the light guide section above the light receiving section, the light projecting section above the light guide section, the microplate above the light projecting section, and the above microplate. It is possible to adopt a structure in which the reflecting member is arranged in the. In this case, the light projecting unit, the light receiving unit, and the light guiding unit are fixed in the housing, the microplate containing the sample is placed on the light projecting unit, and the upper part of the microplate is covered with the reflecting member. Good. Therefore, the microplate reader can be easily set.

Furthermore, in the above-mentioned microplate reader, there is a power feeding circuit to the plurality of light projecting portions, the light projecting substrate to which the light projecting portions are electrically connected, and a power feeding circuit to the plurality of light receiving portions. A light-receiving substrate to which the light-receiving unit is electrically connected, and at least the number of wells of the microplate corresponding to one well of the microplate on the light-projecting substrate, It may further include an aperture part that allows the light reflected by the member and that has passed through the sample to pass therethrough to enter the light-receiving light guide path.
In this case, the power supply to the plurality of light projecting portions can be realized by one printed circuit board on which the wiring pattern is formed. Similarly, the power supply to the plurality of light receiving portions can be realized by one printed circuit board on which the wiring pattern is formed. Therefore, the microplate reader can be downsized.

Further, in the above microplate reader, the light projecting section may be a light emitting diode. Since the light emitting diode (LED) is small in size, it is possible to appropriately install the light projecting portion in each well. Further, since the LED is relatively inexpensive, the microplate reader can be realized at low cost.
Further, in the above microplate reader, the light receiving section may be a light receiving sensor. In this case, the light receiving section can be a color sensor, and the measurement data can be easily obtained.
Further, in the above microplate reader, the light receiving section may be an optical fiber. In this case, the light guided by the plurality of optical fibers can be captured by the image sensor to obtain the light measurement data as the image data. In this case, the optical measurement data corresponding to all the wells can be collectively processed at the same time.

Further, in the above-mentioned microplate reader, at least a part of the light receiving light guide path may be filled with a resin having a light transmission property that constitutes the pigment-containing resin.
In this case, it is possible to suppress reflection and scattering of light at the interface between the light guide path and the surrounding member. Therefore, the measurement error due to stray light can be suppressed more effectively.

Further, in the above-mentioned microplate reader, the light receiving light guide path may be made of a resin having a light transmitting characteristic, and may be configured to include a flat portion and a columnar member extending in a column shape from the flat portion.
With such a configuration, it is possible to suppress the scattering of light incident from the flat portion.
Further, in the above-mentioned microplate reader, a step portion is provided at a connecting portion between the flat portion and the columnar member such that a diameter of the connecting portion side is larger than a diameter of a tip portion side of the columnar member. May be.
With this configuration, the influence of external light can be suppressed.

Further, an aspect of the microplate reader unit according to the present invention is to provide a light projecting section and a light receiving section respectively corresponding to one well of a microplate, and a sample emitted from the light projecting section and accommodated in the corresponding well. Pigment-containing resin containing a pigment having a property of absorbing light in the light-receiving light guide path and the light-receiving light guide path that guides the light that has passed back through the sample after being returned. A light guide part having a surrounding member surrounded by and a limiting part for limiting an angular component of light incident on the light receiving part.
As a result, it is possible to realize a microplate reader which can be miniaturized and can perform optical measurement of all the samples contained in each well of the microplate in a short time and with high accuracy.

Further, in the above-mentioned microplate reader unit, the light receiving light guide path may be made of a resin having a light transmitting property, and may be composed of a flat portion and a columnar member extending in a column shape from the flat portion.
With such a configuration, it is possible to suppress the scattering of light incident from the flat portion.
Further, in the above microplate reader unit, a step portion is provided at a connecting portion between the flat portion and the columnar member so that a diameter of the connecting portion side is larger than a diameter of a tip portion side of the columnar member. May be.
With this configuration, the influence of external light can be suppressed.

The microplate reader of the present invention can be miniaturized and can perform optical measurement of all the samples contained in each well of the microplate with high accuracy.
The above-mentioned objects, modes and effects of the present invention and those not mentioned above are for those skilled in the art to carry out the following inventions by referring to the attached drawings and the description of claims. It can be understood from the form (detailed description of the invention).

FIG. 1 is a schematic configuration diagram of a microplate reader according to this embodiment. FIG. 2 is an exploded perspective view of the main part of the microplate reader. FIG. 3 is an example of a power source line for a light source and a sensor. FIG. 4 is a diagram illustrating external light entering the light guide path. FIG. 5 is a diagram illustrating a setting method of the microplate reader. FIG. 6 is a diagram illustrating a setting method of the microplate reader. FIG. 7 is a diagram illustrating a setting method of the microplate reader. FIG. 8 is a diagram for explaining the influence of external light. FIG. 9 is a diagram showing another example of the mirror plate. FIG. 10 is a diagram showing another example of the mirror plate. FIG. 11 is a diagram showing another example of the mirror plate. FIG. 12 is a diagram showing a configuration for collectively processing the measurement data. FIG. 13 is a diagram showing the configuration of the microplate reader unit. FIG. 14 shows an arrangement example of the microplate reader unit. FIG. 15 is another example of the microplate reader unit. FIG. 16 is a measurement example of a 96-well microplate. FIG. 17 is a measurement example of a 6-well microplate. FIG. 18 is a diagram showing another example of the microplate. FIG. 19 is a schematic configuration diagram of a microplate reader using a condenser lens. FIG. 20A is a diagram showing an example of a manufacturing process of the light guide plate section. FIG. 20B is a diagram showing an example of a manufacturing process of the light guide plate section. FIG. 20C is a diagram showing an example of a manufacturing process of the light guide plate section. FIG. 20D is a diagram showing a defect of the light guide plate portion. FIG. 21A is a diagram showing another example of the manufacturing process of the light guide plate section. FIG. 21B is a diagram showing a light guide plate portion including a flat portion and a columnar member. FIG. 22A is a diagram showing another example of the manufacturing process of the light guide plate section. FIG. 22B is a diagram showing a light guide plate portion having a step portion. FIG. 23 shows an example of a scanning type microplate reader. FIG. 24 is a diagram showing a main part of a scanning type microplate reader. FIG. 25 is another example of the scanning type microplate reader. FIG. 26A is a diagram showing the position of the microplate at the time of the first light measurement. FIG. 26B is a diagram showing the position of the microplate at the time of the second light measurement.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic configuration diagram of a microplate reader 10 according to this embodiment. Further, FIG. 2 is an exploded perspective view showing a configuration of a main part of the microplate reader 10.
The microplate reader 10 includes a light projecting substrate 11a, a measuring substrate 11b, a plurality of light sources (light projecting units) 12a, a plurality of light receiving sensors (light receiving units) 12b, and a light guiding plate unit (light guiding unit). 13, a mirror plate (reflection member) 14, a housing 15, a power supply unit 16, and power supply cables 17a and 17b.

The light projecting substrate 11a, the measuring substrate 11b, the plurality of light sources 12a, the plurality of light receiving sensors 12b, the light guide plate portion 13, the power source portion 16 and the power feeding cables 17a and 17b are housed in a housing 15 having an opening above. Placed and fixed. As shown in FIG. 2, the microplate reader 10 according to the present embodiment is provided with a plurality of light receiving sensors 12b on a measurement substrate 11b, and a light guide plate portion 13 provided on the measurement substrate 11b. A light projecting substrate 11 a is provided on the plate portion 13. A plurality of light sources 12a are provided on the light projecting substrate 11a. The microplate 20 can be installed on the light projecting substrate 11a in the housing 15.
Further, the micro plate reader 10 is configured such that the mirror plate 14 is arranged on the micro plate 20 installed on the light guide plate portion 13. The surface 14a of the mirror plate 14 facing the microplate 20 is a reflection surface (mirror surface). The mirror plate 14 closes the opening of the housing 15 and functions as an upper lid of the microplate 20.

(Micro plate)
The microplate 20 is a flat member made of, for example, acrylic, polyethylene, polystyrene, glass, or the like. As shown in FIG. 2, the microplate 20 is, for example, a rectangular flat plate, and a large number of wells 21 are provided on the surface thereof. The shape of the well 21 is, for example, a columnar shape having a flat bottom. Further, the number of wells 21 is 6, 24, 96, 384, 1536, etc., and the capacity is several μl to several ml. The microplate 20 shown in FIG. 2 is an 8 × 12 96-well microplate.

(Emitting section and light receiving section)
The light source 12a is a light projecting unit that emits light, and is arranged on one surface (upper surface) of the light projecting substrate 11a. The light receiving sensor 12b is a light receiving unit that receives light, and is arranged on one surface (upper surface) of the measurement substrate 11b. The light source 12a is, for example, a light emitting diode (LED), and the light receiving sensor 12b is, for example, an RGB color sensor. The light source 12a can be, for example, a chip LED (surface mount LED). In this case, one light source 12a includes a chip LED having a plurality of light emitting portions (light emitting points).
The microplate reader 10 includes the same number of light sources 12a and light receiving sensors 12b as the wells 21 of the microplate 20. That is, one light source 12a and one light receiving sensor 12b are provided corresponding to one well 21 of the microplate 20. For example, when the microplate 20 has 96 wells 21 as shown in FIG. 2, 96 light sources 12a are provided on the light projecting substrate 11a, and 96 light receiving sensors 12b are provided on the measuring substrate 11b. To be

(Emitting substrate and measuring substrate)
The light projecting substrate 11a has a light source power source line to which the light source 12a is connected. The plurality of light sources 12a are connected to a light source power source line provided on the light projecting substrate 11a and obtain power from the light source power source line. Electric power is supplied from the power supply unit 16 to the light source power supply line of the light projecting substrate 11a through the power supply cable 17a.
Similarly, the measurement substrate 11b has a sensor power supply line to which the light receiving sensor 12b is connected. The plurality of light receiving sensors 12b are connected to the sensor power supply line provided on the measurement substrate 11b, and obtain power from the sensor power supply line. Power is supplied from the power supply unit 16 to the sensor power supply line of the measurement substrate 11b through the power supply cable 17b.

The plurality of light sources 12a are connected in parallel to the light source power source line as shown in FIG. 3, for example. Similarly, the plurality of light receiving sensors 12b are connected in parallel to the sensor power supply line, as shown in FIG. 3, for example.
There are two wiring portions for power supply, which are connected to the light source 12a and the light receiving sensor 12b, respectively. Therefore, when 96 light emitting units and 96 light receiving units are provided as in the present embodiment, 384 wirings are required. In order to compact the enormous amount of wiring in this way, the light projecting substrate 11a and the measuring substrate 11b are configured as printed boards on which the wiring patterns (feeding circuits) are formed. The measurement substrate 11b may be provided not only with a power feeding circuit for the light receiving sensor 12b but also with a sensor output circuit, a communication circuit for outputting the sensor output to the outside, and the like.

Further, the light projecting substrate 11a is provided with the same number of aperture portions 11c as the light sources 12a. The aperture section 11c can pass the light emitted from the light source 12a, passing through the sample 30 or the like housed in the well 21, reflected by a mirror plate described later, and passing through the sample 30 or the like again to be emitted. .
In the aperture section 11c, when the light projecting substrate 11a is placed on the light guide plate section 13, the light emitting end of the aperture section 11c is made to enter a light receiving light guide path 13a of the light guide plate section 13 described later. It is provided on the light projecting substrate 11a so as to be arranged at a position corresponding to the edge. Further, the aperture portion 11c is arranged such that, when the microplate 20 is placed on the light projecting substrate 11a, the light incident end of the aperture portion 11c corresponds to the bottom surface of the well 21 of the microplate 20. Thus, it is provided on the light projecting substrate 11a. Further, the light source 12a is provided adjacent to the aperture portion 11c, and the light source 12a is also disposed at a position corresponding to the bottom surface of the well 21 of the microplate 20.
Further, the aperture portion 11c has a diameter smaller than the opening at the light incident end of the light receiving light guide path 13a in order to limit the angle component of light entering the light receiving light guide path 13a described later.

(Light guide plate part)
The light guide plate portion 13 includes a light receiving light guide path 13a. The light receiving light guide path 13a is emitted from the light source 12a provided on the light projecting substrate 11a, passes through the sample 30 or the like housed in the well 21, is reflected by the mirror plate described later, and passes through the sample 30 or the like again. The emitted light is guided to the light receiving sensor 12b. In the present embodiment, the light receiving light guide path 13a is a straight optical path arranged in the vertical direction so that the light guide plate section 13 itself is small.
The light guide plate portion 13 includes the same number of light receiving light guide paths 13a as the wells 21 of the microplate 20. That is, one light receiving light guide path 13a is provided corresponding to one well 21 of the microplate 20. For example, as shown in FIG. 2, when there are 96 wells 21 in the microplate 20, the light guide plate portion 13 includes 96 light receiving light guide paths 13a.

The light-receiving light guide path 13a is provided on the light-guide plate portion 13 such that the light emitting end of the light-receiving light guide path 13a is located at a position corresponding to the light-receiving sensor 12b provided on the measurement substrate 11b. There is. Further, in the light receiving light guide path 13a, when the light projecting substrate 11a is placed on the light guide plate 13, the light incident end of the light receiving light guide path 13a corresponds to the aperture portion 11c of the light projecting substrate 11a. It is provided on the light guide plate portion 13 so as to be arranged at the position. As a result, the light incident end of the light receiving light guide path 13 a is arranged at a position corresponding to the bottom surface of the well 21 of the microplate 20 installed on the light guide plate 13.
That is, the bottom surface of each well 21 is positioned at the position where the bottom surface of each well 21 faces the light incident end of the light guide path 13a for light reception by the positioning means (not shown).
Thus, the light guide path corresponding to each well 21 is one of the light receiving light guide paths 13a, and the light source 12a on the light projecting substrate 11a is adjacent to the optical axis of the aperture section 11c or the light receiving light guide path 13a. It is possible to provide. Therefore, for example, even when the well itself is small as in a 384-well microplate, the light projecting unit, the light receiving unit, and the light guiding unit can be arranged corresponding to each well 21. Appropriate light measurement is possible.

  The light receiving light guide path 13a is transparent to the light emitted from the light source 12a, passing through the sample 30 and the like housed in the well 21, reflected by the mirror plate 14, and passing through the sample 30 and the like again and emitted. It is made of resin (for example, silicone resin). The light receiving light guide path 13a is surrounded by a surrounding member 13b made of a pigment-containing resin. Here, the pigment-containing resin is a resin having a light transmitting property (for example, a silicone resin) containing a pigment having a property of absorbing stray light. As the pigment, for example, carbon black, which is a black pigment, or the like can be adopted.

In the present embodiment, the material of the transparent resin that constitutes the light-receiving light guide path 13a and the resin having light transparency that constitutes the pigment-containing resin are the same. This suppresses reflection and scattering at the interface between both resins. In addition, the stray light incident on the pigment-containing resin is absorbed by the pigment-containing resin and hardly returns to the light-receiving light guide 13a, so that complicated multiple reflection of stray light hardly occurs.
As shown in FIG. 4, in the noise light L11 such as external light that enters the light-receiving light guide path 13a, the component that travels in the same direction as the optical axis of the light-receiving light guide path 13a is very small, and most of it is for the light-receiving light path. The light enters the pigment-containing resin from the interface between the light guide path 13a and the surrounding member 13b made of the pigment-containing resin, and is absorbed by the pigment. At this time, the reflection at the interface does not occur by using the same material for the transparent resin forming the light receiving light guide path 13a and the pigment-containing resin forming the surrounding member 13b.

The external light incident on the pigment and its scattered light are almost absorbed by the pigment, but are slightly scattered on the surface of the pigment. However, the scattered light often enters the surrounding member 13b made of the pigment-containing resin again, and is absorbed by the pigment of the pigment-containing resin.
Therefore, as shown in FIG. 4, most of the light extracted from the light-receiving light guide path 13a is straight light L1 along the optical axis of the light-receiving light guide path 13a.

By the way, depending on the setting of the cross-sectional area and the optical path length of the light receiving light guide 13a, a part of the scattered light slightly scattered by the pigment surface may be emitted from the light emitting end of the light receiving light guide 13a. Therefore, it is preferable to appropriately set the cross-sectional area and the optical path length of the light receiving light guide path 13a and attenuate the intensity thereof to such an extent that the measurement is not affected.
When the area of the light incident end of the light receiving light guide path 13a increases, the amount of light incident on the light receiving light guide path 13a increases. Therefore, when the area of the light incident end becomes large, the intensity of the straight light traveling through the light receiving light guide path 13a is also scattered at the light incident end of the light receiving light guide path 13a and reaches the light emitting end as scattered light. Also becomes stronger.

The present inventors investigated the intensity dependence of straight light and the intensity dependence of external light with respect to the area of the light incident end of the light guide path 13a for light reception. As a result, it was found that the amount of increase in the intensity of outside light with respect to the increase in the diameter of the light receiving light guide 13a was larger than the amount of increase in the intensity of the measurement light.
That is, it was found that the smaller the area of the light incident end of the light receiving light guide 13a, the higher the S / N ratio. Specifically, the ratio (√A / L) of the square root of the area (A) of the light receiving end of the light receiving optical waveguide 13a to the distance (L) from the light incident end to the light emitting end is 0.4 or less. It has been found that the optical measurement with a sufficiently high S / N ratio is possible.
Therefore, it is preferable that the cross-sectional area and the optical path length of the light receiving light guide 13a be set so as to satisfy the above conditions. As a result, it is possible to appropriately suppress the adverse effect of scattered light on the light measurement.

(Mirror plate)
The surface 14a of the mirror plate 14 facing the microplate 20 is a reflection surface (mirror surface). Therefore, the light emitted from each light source 12 a and passing through the sample 30 contained in each well 21 of the microplate 20 reaches the mirror plate 14 and then is reflected by the reflecting surface 14 a of the mirror plate 14.
The light reflected by the reflecting surface 14a of the mirror plate 14 passes through the sample 30 housed in each well 21 of the microplate 20 again. The light that has passed through the sample 30 passes through each aperture portion 11c provided on the light projecting substrate 11a and each light receiving light guide path 13a of the light guide plate portion 13 and enters each light receiving sensor 12b.

Next, a method of setting the microplate reader 10 according to this embodiment will be described.
As shown in FIG. 5, inside the housing 15, a measurement substrate 11b, a plurality of light receiving sensors 12b, a light guide plate portion 13, a light projecting substrate 11a, a plurality of light sources 12a, a power source portion 16 and power supply cables 17a and 17b are provided. As shown in FIG. 6, the operator installs the microplate 20 in which the sample 30 is stored in each well 21 on the microplate reader 10 in the fixed state. At this time, the microplate 20 is placed on the light projecting substrate 11a. At this time, the microplate 20 is arranged such that the bottom surface of each well 21 faces the light incident end of the light receiving light guide path 13a via the aperture portion 11c provided in the light projecting substrate 11a one by one. So that it is positioned.

Next, as shown in FIG. 7, the operator installs the mirror plate 14 on the microplate 20. At this time, the operator holds the mirror plate 14 on the micro plate 20 so as to close the opening of the housing 15 by holding the grip portion 14 b provided on the surface of the mirror plate 14 opposite to the reflection surface 14 a. Install. The mirror plate 14 may be vertically positioned by a positioning member (not shown).
After installing the mirror plate 14 on the micro plate 20, the operator operates a power switch or the like (not shown) to supply power to the light sources 12a and the light receiving sensors 12b from the power source section 16 via the power supply cables 17a and 17b. To supply. As a result, light is emitted from each light source 12a.

The light emitted from each light source 12 a passes through the sample 30 contained in each well 21 of the microplate 20 and reaches the mirror plate 14. Then, the light reaching the mirror plate 14 is reflected by the reflecting surface 14 a of the mirror plate 14 and passes through each well 21 again. The light passing through each well 21 passes through the aperture portion 11c of the light projecting substrate 11a and each light receiving light guide path 13a of the light guide plate portion 13 and is received by the light receiving sensor 12b. In this way, the optical characteristics (eg, light absorption characteristics) of the sample 30 are measured.
The measurement result obtained by the light receiving sensor 12b may be transmitted to an external device as light intensity information via a data communication unit (not shown). In this case, the external device measures the optical characteristics of the sample 30 based on the above light intensity information.

As described above, the microplate reader 10 according to the present embodiment is arranged below the horizontally arranged microplate 20, and the light source 12a and the light receiving unit as a light projecting unit corresponding to one well 21 of the microplate 20. As many sets as the number of the wells 21 of the microplate 20. Further, the microplate reader 10 is provided above the microplate 20 and includes a mirror plate 14 that reflects the light that has passed through the sample 30 housed in the well 21 from the light projecting portion side to the light receiving portion side.
Further, the plurality of light sources 12 a are provided on the light projecting substrate 11 a, and the light projecting substrate 11 a passes through the sample 30 emitted from the light source 12 a and stored in the well 21 and reflected by the mirror plate 14. An aperture portion 11c that allows the light reflected by the surface 14a and passing through the sample 30 again to pass therethrough is provided. The aperture portions 11c are provided at least as many as the number of the wells 21 of the microplate 20 corresponding to one well 21 of the microplate 20, and have a diameter smaller than the opening of the light receiving end of the light receiving guide path 13a. . The microplate reader 10 is arranged between the light projecting unit and the light receiving unit, and guides the light reflected by the reflecting surface 14a of the mirror plate 14 and passing through the sample 30 to the light receiving sensor 12b. 13a and a light-guiding plate portion 13 having an enclosing member 13b that encloses the light-receiving light guide path 13a with a pigment-containing resin.

As described above, according to the microplate reader 10 in the present embodiment, the light source 12a for irradiating the sample 30 contained in the well 21 with light is provided corresponding to all the wells 21 of the microplate 20. A light receiving sensor 12b that measures the light emitted from the sample 30 is provided.
Conventionally, there is no idea to provide a light source and a light receiving sensor corresponding to all the wells 21 of the microplate 20, and the microplate 20 is scanned every time one light measurement is performed, and all the wells 21 are measured by a plurality of measurements. I was measuring light. Therefore, it takes time to measure the light of all the wells 21.
In the present embodiment, all the optical measurement of the sample 30 contained in each well 21 of the microplate 20 is performed by one measurement without scanning the microplate 20 for each optical measurement as in the conventional case. It can be done at the same time. Therefore, the measurement time can be shortened. Further, since a complicated driving mechanism for scanning the microplate 20 is not necessary, the device size can be reduced.

  Further, the microplate reader 10 guides the light, which is irradiated from the light source 12a to the sample 30 contained in each well 21 of the microplate 20 and has passed through the well 21, to the light receiving sensor 12b through the well 21 again. The mirror plate 14 is provided. Therefore, the length of the optical path portion can be shortened as compared with the case where the light projecting portion and the light receiving portion are arranged to face each other in the vertical direction with the microplate 20 sandwiched therebetween. Therefore, miniaturization of the device can be realized.

Further, the light guide plate portion 13 has a configuration in which a light receiving light guide path 13a made of a transparent resin (silicone resin) is surrounded by an enclosure member 13b made of a pigment-containing resin capable of absorbing external light and scattered light. . Therefore, it is possible to suppress the influence of the noise light (stray light) from the external light or the scattered light.
In particular, by using the same material for the transparent resin and the pigment-containing resin, it is possible to appropriately suppress reflection and scattering at the interface between the two resins. That is, the stray light incident on the pigment-containing resin is absorbed by the pigment-containing resin and hardly returns to the light guide path, and complicated multiple reflection of stray light hardly occurs. Further, by appropriately setting the cross-sectional area and the optical path length of the light receiving light guide path 13a, the influence of external light can be significantly suppressed.

That is, even if outside light enters the inside of the device, the influence of outside light is significantly attenuated in the light receiving light guide path 13a in the light guide plate portion 13. Therefore, it is not necessary to strictly take measures against noise light with respect to the optical system inside the microplate reader, and the device itself does not become large-scale due to the measures against noise light.
The technology of a monolithic optical system using a silicone resin as described above is called SOT (Silicone Optical Technologies). In this embodiment, by adopting the SOT structure in the optical system of the microplate reader, the influence of external light (noise light) can be almost ignored, and downsizing of the device and highly accurate optical measurement can be realized. Microplate reader.

Further, in the microplate reader 10 of the present embodiment, the microplate 20 is arranged on the light projecting substrate 11a, and the light from the light source 12a on the light projecting substrate 11a travels from the bottom surface of the microplate 20 to the well 21. It is directly projected. When the light projecting substrate 11a (light source 12a) is arranged below the light guide plate portion 13 and the microplate 20 is arranged on the light guide plate portion 13, the light guide plate portion 13 emits light from the light source 12a. A light projecting light guide path is required for guiding the reflected light to the well 21 of the microplate 20. However, in the present embodiment, the light guide plate portion 13 only needs to include the light receiving light guide path 13a. The light receiving light guide path 13a can be a straight optical path arranged in the vertical direction.
As described above, the microplate reader 10 according to the present embodiment includes only one light guide path corresponding to each well 21. Further, the light guide path can be a straight optical path arranged in the vertical direction. Therefore, the light source 12a on the light projecting substrate 11a can be provided adjacent to the optical axis of the aperture portion 11c or the light receiving light guide path 13a. Therefore, for example, even when the well itself is small as in a 384-well microplate, appropriate light measurement is possible.

Further, the aperture portion 11c provided on the light projecting substrate 11a has a smaller diameter than the opening of the light receiving light guide path 13a at the light incident end. Therefore, it is possible to limit the angular component of the light that enters the light-receiving light guide path 13a. That is, it is possible to limit the incident angle of light that reaches the light receiving sensor 12b without entering the interface between the light receiving light guide path 13a and the surrounding member 13b. As described above, the microplate reader 10 according to the present embodiment has the limiting unit that limits the angular component of the light incident on the light receiving sensor 12b.
Therefore, for example, as in a 384-well microplate, the well itself is small, the distance between the centers of the wells is short (for example, 4.5 mm), and it is necessary to arrange a plurality of light sources 12a close to each well. Even if there is, it is possible to suppress the influence of stray light and perform appropriate light measurement.

  The microplate reader 10 also includes a housing 15 in which the microplate 20 is placed. The housing 15 may be made of, for example, a material having a light blocking property or a heat insulating property. In this case, the influence of external light incident from the side surface of the microplate 20 and the influence of temperature can be suppressed. Therefore, the reliability of the measurement data of the well 21 located at the end of the microplate 20 can be ensured.

  As described above, the microplate reader 10 according to the present embodiment is miniaturized to be portable in the field of POCT inspection and the like, and the optical measurement of all the samples 30 accommodated in each well 21 of the microplate 20 can be performed in a short time. Can be performed with high precision.

  Although the influence of outside light (noise light) can be almost ignored by the structure of the light guide plate portion 13 described above, further measures against noise light may be taken. Generally, the light emitted from a chip LED has a predetermined spread. Therefore, for example, as shown in FIG. 8, a part L21 of the light emitted from the light source 12a and passing through the well 21 and the sample 30 reaches the reflecting surface 14a of the mirror plate 14 and is incident on the adjacent well 21. Can be considered. In this case, a part of the light component L21 incident on the adjacent well 21 may pass through the corresponding light receiving light guide path 13a and reach the light receiving sensor 12b as noise light. When the intensity of the light (signal light) emitted from the light source 12a is small, even weak noise light is likely to adversely affect the measurement result, and thus it is necessary to suppress the influence of such noise light. Comes out.

In this case, the area of the reflecting surface 14a of the mirror plate 14 may be limited so that the light passing through the well 21 is incident only on the well 21 again. FIG. 9 is an example of the mirror plate 14 in which the area of the reflecting surface 14a is limited.
In FIG. 9, the reflection surface 14a of the mirror plate 14 is limited above each well 21 of the microplate 20, and the periphery of the reflection surface 14a is a non-reflection surface 14c. The shape of the reflecting surface 14a can be circular as shown in FIG. 10, for example. When the reflecting surface 14a is circular, the reflecting surface 14a is provided in the mirror plate 14 at a position such that the center of the circle is substantially the same as the central axis of each well 21.

In this way, on the surface of the mirror plate 14 facing the microplate 20, the reflecting surface 14a may be selectively provided depending on the formation position of the light receiving light guide path 13a. By limiting the reflection surface 14a as described above, it is possible to limit the angular component of the light incident on the light receiving sensor 12b by preventing a part of the light spread from the light source 12a from being reflected. That is, by providing the mirror plate 14 with the reflecting surface 14a and the non-reflecting surface 14c, it is possible to realize a limiting unit that limits the angular component of the light incident on the light receiving sensor 12b. This makes it possible to prevent a part of the light that has passed through one well 21 and reached the mirror plate 14 from entering another well 21 adjacent to the well 21. Therefore, a highly accurate measurement result can be obtained.
When the non-reflective surface 14c of the mirror plate 14 is irradiated with light, slight light reflection may occur on the non-reflective surface 14c. When the intensity of the reflected light may adversely affect the measurement result, the AR corresponding to the wavelength of the light emitted through the sample 30 contained in the well 21 is provided in the non-reflective surface area. (Anti-Reflection) coating may be applied. Alternatively, as shown in FIG. 11, a light absorbing member 14d made of the same pigment-containing resin as the surrounding member may be provided in the non-reflection surface region.

  Further, as described above, the microplate reader 10 in the present embodiment can acquire measurement data for all the wells 21 of the microplate 20 almost at the same time. However, the processing of the measurement data is not always performed at the same time. For example, one data processing may be performed on eight wells, and this may be performed 12 times. In this case, it takes some time for data processing.

Therefore, the microplate reader 10 may have a structure capable of simultaneously processing the measurement data corresponding to each well 21 at once.
In this case, as shown in FIG. 12, the microplate reader 10 has a structure in which the light emitted from the sample 30 housed in each well 21 and guided by the light receiving light guide path 13 a is received by the optical fiber 51. It may be. That is, the tip (incident end) 51a of the optical fiber 51 may be arranged as the light receiving section instead of the light receiving sensor 12b.

  The optical fibers 51 that receive the light that has passed through the light-receiving light guide paths 13a corresponding to the wells 21 can be bundled on the light emission end side. In this case, the light emitted from the optical fiber bundle in which the optical fibers 51 are bundled can be captured by the image sensor 52. The image data captured by the image sensor 52 is the light measurement data corresponding to all the wells 21 of the microplate 20, and the light measurement data corresponding to all the wells 21 are collectively processed by processing the image data. It is possible to process data at the same time.

In the present embodiment, the microplate reader 10 arranges the light guide plate section 13 on the light receiving section composed of the light receiving sensor 12b, and arranges the light projecting section composed of the light source 12a on the light guide plate section 13. Then, the case where the microplate 20 is arranged on the light projecting portion and the mirror plate is arranged on the microplate 20 has been described. That is, the above-described microplate reader 10 irradiates light from below the well 21 of the microplate 20, reflects the light that has passed through the well 21 above the well 21, and passes the well 21 again to pass the light of the well 21. It is a structure that receives light from the bottom side.
However, the structure may be such that light is emitted from above the well 21 of the microplate 20, light that has passed through the well 21 is reflected on the bottom surface side, passes through the well 21 again, and receives light above the well 21. However, the structure in which light is emitted from the bottom surface side of the well 21 of the microplate 20 as described above is preferable because the setting of the microplate 20 is easy.

(Second embodiment)
Next, a second embodiment of the present invention will be described.
In the above-described first embodiment, the microplate reader corresponding to the microplate having the predetermined number of wells (96 wells) has been described. In the second embodiment, a microplate reader compatible with microplates having different numbers of wells will be described.
For example, when cell culture is performed using a microplate and light measurement is performed on the cultured cells, a microplate having a small number of wells (for example, 6 wells) is used. In order to handle such different types of microplates, a unit unit (microplate reader unit) corresponding to only one well is used in this embodiment.

FIG. 13 is a diagram showing a configuration example of the microplate reader unit 18.
As shown in FIG. 13, the microplate reader unit 18 includes a light source 18a, a light receiving sensor 18b, a unit light projecting substrate 18c, an aperture portion 18d, a light receiving light guide path 18e, and an enclosing member 18f. Prepare Here, the light source 18a and the light receiving sensor 18b are the same as the light source 12a and the light receiving sensor 12b in the above-described first embodiment. The aperture section 18c is similar to the aperture section 11c in the above-described first embodiment. Further, the light receiving light guide path 18e and the surrounding member 18f are the same as the light receiving light guide path 13a and the surrounding member 13b configuring the light guide plate portion 13 in the above-described first embodiment.

The microplate reader unit 18 is configured to be attachable to and detachable from the measurement substrate 111. The measurement substrate 111 can be electrically connected to the power supply circuit formed on the substrate and the light receiving sensor 18b of the microplate reader 18 on the surface of the substrate similar to the measurement substrate 11b in the first embodiment described above. It has a configuration including a connector portion 112.
For example, 96 connector portions 112 are provided on the measurement substrate 111 so as to be arranged at positions corresponding to the respective wells of a 96-well microplate, for example. Specifically, the connector portions 112 are respectively provided on the measurement substrate 111 at positions corresponding to the light receiving sensor 12b shown in FIG. 2, for example. The microplate reader unit 18 has a size corresponding to one well of a 96-well microplate, and a maximum of 96 microplate reader units 18 can be mounted on the measurement substrate 111 corresponding to each well of the 96-well microplate. Is.

  Here, when the microplate reader unit 18 is mounted on the measurement substrate 111, the unit light projecting substrates 18c of the microplate reader unit 18 can be electrically connected to the unit light projecting substrates adjacent to each other. Is configured. Thus, for example, when 96 unit light projecting substrates 18c are electrically connected, an electric circuit configuration equivalent to that of the light projecting substrate 11a shown in FIG. 2 is obtained.

FIG. 14 is a diagram showing an example of the microplate reader 10A in the present embodiment, and is a diagram when a plurality of microplate reader units 18 are mounted adjacent to each other on the measurement substrate 111. As shown in FIG. 14, the structure in which a plurality of microplate reader units 18 are connected to the measurement substrate 111 is part of the microplate reader 10 in the first embodiment shown in FIG. 1 (projection substrate 11a, The light source 12a, the measurement substrate 11b, the light receiving sensor 12b, and the light guide plate portion 13) have the same structure.
Therefore, the microplate reader 10A in which 96 microplate reader units 18 are connected to the measurement substrate 111 has the same structure as the microplate reader 10 in the first embodiment shown in FIG.

13 and 14, the example in which the microplate reader unit 18 is a unit unit corresponding to only one well 21 is shown, but the present invention is not limited to this, and the microplate reader unit 18 includes a plurality of units. A unit unit corresponding to the well 21 may be used. For example, the microplate reader unit 18 may be a unit unit corresponding to eight wells 21, and twelve unit light guide unit portions 182 may be used for the 96-well microplate 20.
FIG. 15 shows an example in which the microplate reader unit 18 corresponds to a plurality of wells 21.

The microplate reader 10A according to the present embodiment has a microplate reader unit 18 appropriately arranged according to the number and positions of the wells 21 of the microplate 20 used for the optical measurement.
For example, when the 96-well microplate 20 is used, as shown in FIG. 16, 96 microplate reader units 18 are arranged at positions corresponding to the 96 wells 21, respectively. These 96 microplate reader units 18 are connected to the wiring 60 formed on the measurement substrate 111, and are configured to be able to supply power. At this time, electric power is similarly supplied to the light projecting substrate formed by connecting the plurality of unit light projecting substrates 18c. Here, as the connection method of the wiring 60, multi-drop connection or daisy chain connection can be used.

On the other hand, when the 6-well microplate 20 is used, as shown in FIG. 17, the 6 microplate reader units 18 are arranged at the positions corresponding to the 6 wells 21, respectively. Also in this case, these six microplate reader units 18 are connected to the wirings 60 formed on the measurement substrate 111 and are configured to be able to supply power. At this time, electric power is similarly supplied to the light projecting substrate formed by connecting the plurality of unit light projecting substrates 18c.
In addition, although the case where one microplate reader unit 18 is arranged for one well 21 has been described in FIG. 17, a plurality of microplate reader units 18 may be arranged for one well 21. In this case, statistics of the measurement data of the plurality of microplate reader units 18 corresponding to one well 21 may be adopted as the measurement data for the one well 21.

  As described above, in the microplate reader unit 10A according to the present embodiment, the number of the microplate reader units 18 required at the necessary position on the measurement substrate 111 is set according to the number and the positions of the wells 21 of the microplate 20. It has a configuration to arrange only. Therefore, a microplate reader corresponding to the microplates 20 having different numbers of wells can be provided.

  In the present embodiment, the case where the microplate reader unit 18 includes the light projecting unit, the light receiving unit, and the light guide plate unit has been described. However, the light source 18a forming the light projecting unit and the light receiving unit forming the light receiving unit. You may make it include even the board | substrate which has the wiring respectively connected to the sensor 18b. In this case, when the microplate reader unit 18 is arranged so as to correspond to the number and positions of the wells 21 of the microplate 20, the above-mentioned substrate constituting the unit can be connected to a power supply cable connected to the power supply section. If

(Modification)
In each of the above embodiments, the case where the light receiving light guide paths (13a, 18e) are made of a transparent resin has been described, but these light receiving light guide paths may be hollow. In that case, although the effect of suppressing stray light reflection at the interface between the light receiving light guide path and the surrounding member (13b, 18f) made of a pigment-containing resin that surrounds the light receiving path cannot be obtained, stray light that has entered the pigment-containing resin does not contain the pigment. Since it is absorbed by the resin, complicated multiple reflection of stray light is suppressed to some extent.

Further, in each of the above-described embodiments, the case where the bottom surface of the well of the microplate 20 has a flat plate shape has been described. When the bottom surface of the well has a flat plate shape, it is preferable because it has good contact with the light guide plate portion 13, but the shape of the bottom surface of the well does not necessarily have to be a flat plate shape.
For example, as shown in FIG. 18, the shape of the bottom surface of the well 22 of the microplate 20 may be spherical. In this case, since a slight gap is formed between the light incident end of the light receiving light guide path 13a and the bottom surface of the well 22, external light may enter. However, by appropriately setting the cross-sectional area and the optical path length of the light receiving light guide path 13a, the intensity of external light can be attenuated to the extent that the measurement result is not affected.

Further, in each of the above-described embodiments, the light projecting unit (light source) and the light receiving unit (light receiving sensor) may be configured to be able to be individually driven one set at a time. In this case, it is possible to selectively drive the necessary number and positions of the light projecting section and the light receiving section according to the number and the positions of the wells of the microplate. This makes it possible to provide a microplate reader compatible with microplates having different numbers of wells.
In each of the above embodiments, the number of light projecting units (light sources), the number of light receiving units (light receiving sensors) and the number of wells do not necessarily have to match, and the number of wells is smaller than the number of light projecting units and light receiving units. Can also be placed.
Further, in each of the above-described embodiments, the microplate is not necessarily arranged horizontally, and the light projecting unit and the light receiving unit are not necessarily arranged in the vertical direction. For example, the microplate may be arranged vertically, or the microplate may be arranged vertically. The sample contained in the well can be appropriately modified within the range in which the sample contained in the well can be optically measured, for example, by arranging the light projecting section and the light receiving section in the diagonal direction of the plate.

Further, in each of the above-described embodiments, the diameter of the aperture portion 11c is made smaller than the diameter of the light incident end of the light receiving light guide path 13a as a limiting portion for limiting the angle component of the light incident on the light receiving sensor 12b. The case where the mirror plate 14 is provided with the reflecting surface 14a and the non-reflecting surface 14c has been described. However, the restriction unit is not limited to the above.
For example, as in the microplate reader 10B shown in FIG. 19, the light source 12a may be provided with a condenser lens 11d. In addition, in FIG. 19, portions having the same configuration as the microplate reader 10 shown in FIG. 1 are denoted by the same reference numerals as those in FIG.

  Here, the condenser lens 11d can be made of, for example, a resin (for example, PDMS resin) that is solidified after being dropped on the chip LED. By thus providing the condenser lens 11d, the spread of the light emitted from the light source 12a can be limited, and as a result, the angular component of the light incident on the light receiving sensor 12b can be limited.

  The limiting portion for limiting the angle component of the light incident on the light receiving sensor 12b is limited by using the aperture portion 11c of the light projecting substrate 11a, limiting by using the non-reflective surface 14c of the mirror plate 14, Also, at least one of the restrictions using the condenser lens 11d of the light source 12a may be used, and these may be appropriately combined and used. For example, when the limiting section is a limitation using the non-reflective surface 14c of the mirror plate 14 or a condenser lens 11d of the light source 12a, the diameter of the aperture section 11c of the light projecting substrate 11a is It may be equal to or more than the opening of the light guide path 13a at the light incident end.

It should be noted that the above-mentioned light guide plate portion 13 is provided with a light receiving light guide path 13a made of a transparent resin (silicone resin) and an enclosing member made of a pigment-containing resin capable of absorbing external light and scattered light. In the case of being surrounded by 13b, the light guide plate portion 13 is manufactured by the following procedure, for example.
As shown in FIG. 20A, first, an enclosing member made of a pigment-containing resin provided with a light guide path cavity 13f in which a light guide path for light reception is formed later is formed.
Next, as shown in FIG. 20B, the surrounding member 13f is placed on the surface plate 40, and the liquid transparent resin 13g is injected into the light guide path cavity 13f. By solidifying this transparent resin 13g, as shown in FIG. 20C, a light guide path 13a made of a transparent resin and a surrounding member 13b made of a pigment-containing resin and surrounding the light guide path 13a for guiding are provided. The light plate portion 13 is obtained.

When the inventors manufactured the light guide plate portion 13 by such a procedure, it was found that the following problems occurred. That is, when the transparent resin 13g is injected and solidified in the light guide cavity 13f, as shown in FIG. 20D, due to the influence of the surface tension when the liquid transparent resin 13g is injected, the light guide waveguide 13a is received. The tip portion (light incident end) 13h is not necessarily flat. In such a case, for example, a part of the light incident from the tip portion (light incident end) 13h is scattered, and the intensity of the light extracted from the light emitting end of the light receiving guide path 13a is reduced.
Further, even if bubbles are generated in the light receiving light guide 13a when the liquid transparent resin 13g is injected, since the light receiving light guide 13a is surrounded by the surrounding member 13b, the bubbles cannot be visually confirmed. Then, when the transparent resin 13g is solidified, the bubbles are fixed as the bubble-shaped hollow portions 13i in the light receiving light guide path 13a.
When light is incident on the bubble-shaped hollow portion 13i, it is scattered, and a part of the scattered light is incident on the enclosing member 13b and absorbed. Therefore, the intensity of the light extracted from the light emitting portion of the light receiving light guide path decreases.

In order to solve such a problem, the inventors manufactured the light guide plate section in the following procedure.
First, as shown in FIG. 21A, a transparent resin member 13m for a light guide path, which is made of a transparent resin and is provided with a columnar section (columnar member) 13k serving as a light guide path for light reception on a flat portion 13j, is molded. In this case, since the light guide transparent resin member 13m is not surrounded by the enclosing member 13b, it is visually confirmed whether or not the bubble-like hollow portion 13i is generated in the light guide transparent resin member 13m. Further, the enclosing member 13b made of a pigment-containing resin provided with the light guide path hollow portion 13f corresponding to the columnar portion 13k is molded.
Then, by fitting the surrounding member 13b and the transparent resin member 13m for the light guide path so that the columnar portion 13k of the transparent resin member 13m for the light guide path is inserted into the hollow portion 13f for the light guide path of the surrounding member 13b, As shown in FIG. 21B, the light guide plate portion 13 including the light receiving light guide path 13a made of a transparent resin and the surrounding member 13b made of a pigment-containing resin and surrounding the light receiving light guide path 13a is obtained.
In addition, it is preferable that the columnar portion 13k of the transparent resin member 13m for a light guide path has a truncated cone shape in which a tapered portion 13n is provided on a side surface so that both can be fitted smoothly.

In the light guide plate portion 13 shown in FIG. 21B, a flat portion 13j made of transparent resin is provided on the upper surface of the light guide plate portion 13, and the lower surface of the flat portion 13j is optically continuous and is a light receiving light guide path. 13a is connected. Therefore, by disposing this flat portion 13j on the light incident side, the scattering of the light incident on the flat portion 13j is the same as the light incident on the tip portion (light incident end) 13h of the light guide plate portion 13 shown in FIG. 20C. Suppressed by scattering. Therefore, it is possible to suppress a decrease in the intensity of light extracted from the light emitting end of the light receiving light guide path 13a of the light guide plate portion 13.
In addition, since the transparent resin member 13m for the light guide and the surrounding member 13b, which are the light guides for receiving light, are individually molded, it is visually confirmed whether or not the bubble-like hollow portion 13i is generated in the transparent resin member 13m for the light guide. be able to. By forming the light guide plate portion 13 by combining the transparent resin member 13m for light guide path, which has been confirmed that the bubble-shaped cavity portion 13i is not formed, and the surrounding member 13b, light scattering caused by the bubble-shaped cavity portion 13i is prevented. It is possible to avoid it.

  In order to reduce the influence of external light incident on the light guide plate portion 13, as shown in FIG. 22A, the diameter of the connection portion side is columnar at the connection portion between the flat portion 13j and the truncated cone columnar portion 13k. 22B is provided so that the diameter is larger than the diameter of the tip portion side of the portion 13k, and as shown in FIG. 22B, the upper portion 13q of the side wall of the surrounding member 13b made of the pigment-containing resin which is illuminated by external light has a light emitting end. It may be hidden from the light receiving sensor arranged on the 13r side.

(Application example)
As described above, in the microplate reader in each of the above-described embodiments, the light receiving light guide path is surrounded by the surrounding member made of the pigment-containing resin capable of absorbing the external light and the scattered light. It is possible to prevent stray light (noise light) from entering the light receiving unit. Further, since the limiting unit that limits the angle component of the light incident on the light receiving unit is provided, the measurement error can be appropriately reduced. Therefore, highly accurate measurement is possible.
Such a structure is also applied to, for example, a microplate reader of a system (hereinafter, referred to as “scan system”) in which a microplate is relatively scanned with respect to a set of a light projecting unit, a light receiving unit, and a light receiving guide path. can do.

In the scanning type microplate reader, a driving mechanism for relatively scanning the microplate is indispensable, and in general, the apparatus itself becomes large-scale. In addition, in the conventional microplate reader, complicated multiple reflections of stray light may occur, and an optical system design corresponding to this may be required.
However, by adopting the optical system configuration (SOT structure) of each of the above-described embodiments, it is not necessary to design an optical system corresponding to stray light in which multiple scattering or the like occurs unlike in the related art. Since the SOT structure has a relatively simple structure, the scan type microplate reader adopting the SOT structure can be downsized as compared with the conventional scan type microplate reader. Further, by adopting the SOT structure, it is possible to improve the accuracy of measurement as compared with the conventional method.

The configuration of the scan-type microplate reader will be described below.
23 and 24 show a main part of a scan type microplate reader 10C adopting the SOT structure. Here, FIG. 24 is a sectional view taken along line XX of FIG. Note that detailed description of the same components as those in the above-described embodiments will be omitted.
As shown in FIG. 24, the microplate reader 10C includes a light projecting substrate 11a ', a measuring substrate 11b', a light source 12a ', a light receiving sensor 12b', and a light guide plate portion 13 '. The measurement substrate 11b 'is provided with a plurality of light receiving sensors 12b', and the light guide plate portion 13 'is provided on the measurement substrate 11b'. The light guide plate portion 13 'has a structure in which a plurality of light receiving light guide paths 13a' are surrounded by a surrounding member 13b 'made of a pigment-containing resin.

A light projecting substrate 11a 'is provided on the light guide plate portion 13', and a plurality of light sources 12a 'are provided on the light projecting substrate 11a'. The light projecting substrate 11a 'is provided with the same number of aperture portions 11c' as the light sources 12a '. The micro plate 20 is installed on the light projecting substrate 11 a ′, and the mirror plate 14 is arranged on the micro plate 20.
When the microplate 20 is arranged and positioned above the light projecting substrate 11a ′, the plurality of light sources 12a ′ provided on the light projecting substrate 11a ′ are respectively provided in predetermined wells 21 of the microplate 20. It is arranged so as to face each other. Further, a plurality of aperture portions 11c 'provided on the light projecting substrate 11a', a plurality of light receiving light guide paths 13a 'provided on the light guide plate portion 13', and a plurality of light receiving devices provided on the measurement substrate 11b '. Similarly, the sensor 12b 'is also arranged so as to face each of a plurality of predetermined wells 21 of the microplate 20.

  Here, the microplate reader 10C includes the same number of light sources 12a ', light receiving sensors 12b', and light receiving light guide paths 13a 'as the rows of wells 21 for one row of the microplate 20. That is, one light source 12a ′, one light receiving sensor 12b ′, and one light receiving light guide path 13a ′ are provided corresponding to each well of one row of the microplate 20.

A plurality of sets of light sources 12a ', light receiving light guide paths 13a', and light receiving sensors 12b 'corresponding to the one well 21 are arranged in the column direction of the wells 21 of the microplate 20 (direction of one side). For example, when the microplate 20 has 8 × 12 = 96 wells, the number of sets of the plurality of light sources 12a ′, light receiving sensors 12b ′, and light receiving light guide paths 13a ′ arranged is 8 or 12.
Further, the light incident end and the light emitting end in one aperture portion 11c ′, the light incident end and the light emitting end in one light receiving light guide path 13a ′, and one light receiving sensor 12b ′ are arranged in a line in the vertical direction. It Further, the arrangement interval of the set of the plurality of light sources 12a ', the light receiving sensor 12b', and the light receiving light guide path 13a 'is equal to the pitch of the wells 21 of the microplate 20.

Therefore, by arranging and positioning the microplate 20 above the light projecting substrate 11a ', the light source 12a', the light receiving sensor 12b 'and the light receiving light guide path 13a are provided so as to correspond to the wells 21 in one row. 'Sets are arranged.
That is, in each well 21 of one row of the microplate 20, the light emitted from one light source 12 a ′ passes through the sample 30 or the like housed in one well 21, is reflected by the mirror plate 14, and is again sampled. After passing through 30 etc., it passes through one aperture section 11c 'and one light receiving light guide path 13a' and reaches one light receiving sensor 12b '.
Thereby, it becomes possible to simultaneously perform the light measurement for one row of the wells of the microplate 20.

  It is not necessary that the light incident end and the light emitting end of the aperture part 11c ′, the light incident end and the light emitting end of the light receiving guide path 13a ′, and the light receiving sensor 12b ′ be arranged exactly in a line in the vertical direction. The light emitted from one light source 12a ′, passing through the sample 30 or the like housed in one well 21 of the microplate 20, reflected by the mirror plate 14, and again emitted through the sample 30 or the like, It is sufficient if the arrangement is such that it can pass through one light receiving light guide path 13a 'and reach one light receiving sensor 12b'.

Then, in the microplate reader 10C having the above-described configuration, the microplate for the set of the plurality of light sources 12a ′, the light receiving sensor 12b ′, and the light receiving light guide path 13a ′ arranged in the column direction of the wells 21 of the microplate 20. By sequentially moving 20 in a direction substantially orthogonal to the column direction of the wells 21, it becomes possible to perform optical measurement on all the wells 21 of the microplate 20.
For example, with respect to the microplate 20 of 8 × 12 = 96 wells, eight groups of the light source 12a ′, the light receiving sensor 12b ′, and the light receiving guide path 13a ′ are provided corresponding to the eight wells 21 in one row. In this case, the direction in which the wells 21 are lined up is the direction in which the wells 21 are sequentially moved.

The above relative sequential movement can be performed by a movement mechanism (not shown). The moving mechanism moves the microplate 20 in a direction orthogonal to the column direction of the wells 21, or sets a set of the light source 12a ′, the light receiving light guide path 13a ′, and the light receiving sensor 12b ′ arranged in a line in the vertical direction to each other. The wells 21 are moved in a direction orthogonal to the column direction while maintaining the positional relationship.
FIG. 23 shows a case where the microplate 20 is fixed, and the set of the light projecting substrate 11a ′, the light guide plate portion 13 ′ and the measuring substrate 11b ′ is sequentially moved by the moving mechanism.

  The moving mechanism can have a control function of, for example, a servo motor or a stepping motor. If the pitch of the wells 21 of the microplate 20 is relatively large, it is not necessary to perform highly accurate position control. Therefore, the moving mechanism can be realized by a mechanical stopper or the like.

As described above, the scan-type microplate reader 10C uses a set of light measurement units (a light source 12a ′, a light-receiving light guide path 13a ′, and a light-receiving sensor 12b ′) that are smaller in number than the wells 21 of the microplate 20. Optical measurement can be performed on all the wells 21 of the microplate 20. Therefore, as compared with the case where the same number of sets of light measurement units as the number of wells 21 are provided as shown in FIG.
Further, in the case of a configuration in which the number of sets of light measurement units is provided by the number of the wells 21 for one row of the microplate 20 and these sets of light measurement units are moved in the direction orthogonal to the column direction of the wells 21, only one uniaxial direction is provided. Since it can be moved, the moving mechanism can be configured relatively easily. When the set of light measurement units is moved in two orthogonal directions, the moving mechanism is increased in size in the height direction, for example, the guide rails are provided in two stages, but if only one axis is moved, the moving mechanism is moved. Can be prevented from becoming large in the height direction, and as a result, the device can be made thin.

Further, in the case of the scanning type microplate reader, it is necessary to relatively move the set of the microplate and the light measurement unit, so that a predetermined gap is formed between the microplate and the light measurement unit. Therefore, outside light is likely to enter or scattered light is likely to be generated in the gap portion.
However, in the above-mentioned microplate reader 10C, the light guide plate portion 13 'having the SOT structure is adopted, and since only the straight light can be taken out, for example, the lower surface of the microplate 20 and the upper surface of the light projecting substrate 11a' are used. Even if a gap is formed between the and, the influence of stray light (noise light) such as external light or scattered light can be ignored. In addition, since it is not affected by outside light, highly accurate light measurement can be performed outdoors.
As described above, the scan-type microplate reader 10C is small in size and capable of highly accurate light measurement, and therefore, it is possible to perform light measurement at a site (on-site) where a sample to be measured is obtained. For example, it can be applied to a mold poison test for imported grains at a port.

  Further, in the above-described microplate reader 10C, the mirror plate 14 arranged above the microplate 20 is fixed, and the light source 12a ', the light receiving sensor 12b', and the light receiving light guide path arranged below the microplate 20 are fixed. The set with 13a 'can be moved by a moving mechanism. As described above, since the member arranged on the upper side of the microplate 20 can be fixed, it is possible to prevent dust accompanying the scan from falling onto the microplate 20.

  23 and 24, the illustration of the housing 15, the power supply unit 16, and the power supply cables 17a and 17b shown in FIG. 1 and the like is omitted, but the moving mechanism for projecting light is used as described above. When moving the set of the substrate 11a ′, the light guide plate portion 13 ′, and the measurement substrate 11b ′, the power supply cables 17a and 17b for feeding power from the power supply unit 16 to the light projection substrate 11a ′ and the measurement substrate 11b ′ are The structure (for example, the length and the arrangement) can follow the movement of the light projecting substrate 11a ', the light guide plate portion 13', and the measuring substrate 11b '.

In addition, in the above-described microplate reader 10C, the case where the set of the light measurement unit including the light projection substrate 11a ′, the light guide plate unit 13 ′, and the measurement substrate 11b ′ is sequentially moved has been described. The set may be fixed and the microplate 20 may be moved sequentially.
However, when the microplate 20 is moved, the liquid surface of the liquid sample 30 contained in each well 21 moves, and it takes time for the liquid surface to stabilize. Therefore, it is possible to maintain the liquid surface in a stable state by moving the set of light measurement units instead of moving the microplate 20, and the light measurement for all the wells 21 can be completed in a short time. It is preferable because it is possible.

  Further, the microplate reader 10C shown in FIG. 23 and FIG. 24 has a set of optical measurement units composed of the same number of light sources 12a ′, light receiving light guide paths 13a ′, and light receiving sensors 12b ′ as the rows of wells 21 of the microplate 20. The case of preparing has been described. However, in the scan-type microplate reader, the number of sets of light measurement units may be any number smaller than the number of wells of the microplate 20, and is not limited to the above.

For example, the number of sets of light measurement units may be smaller than the number of wells 21 for one row of the microplate 20, and the set of light measurement units may be two-dimensionally sequentially moved with respect to the microplate 20. Also in this case, the light measurement can be performed on all the wells of the microplate 20.
Further, the number of sets of light measurement units may be larger than the number of wells 21 in one row of the microplate 20. For example, the number of sets of light measurement units is set to be the same as the number of wells 21 of a plurality of rows such as two rows or three rows of the microplate 20, and the sets of light measurement units are sequentially moved by a plurality of rows. Good.

Furthermore, the set of light measurement units does not necessarily have to be arranged corresponding to each adjacent well of the microplate 20.
As shown in FIG. 1 and the like, in the case of providing a set of light measuring units including the same number of light sources 12a, light receiving light guide paths 13a, and light receiving sensors 12b as the number of wells 21, the larger the number of wells of the microplate 20, The cost of the measuring unit increases. Further, as the number of wells of the microplate 20 increases, the pitch of the wells 21 becomes narrower, which makes it difficult to align the optical measurement unit.

Therefore, like the microplate reader 10D shown in FIG. 25, every other set of the light source 12a ′, the light receiving light guide path 13a ′, and the light receiving sensor 12b ′ may be arranged corresponding to each well 21. Good.
In the case of such a microplate reader 10D, as shown in FIG. 26A, a set of a light source 12a ', a light receiving light guide path 13a' and a light receiving sensor 12b 'is arranged in a checkered pattern with respect to the position of each well 21 of the microplate 20. It may be arranged in a pattern. In this case, by moving the microplate 20 by one row in the direction of the arrow in FIG. 26A, it becomes possible to perform optical measurement on all the wells 21 of the microplate 20 as shown in FIG. 26B.

That is, in the first light measurement, as shown in FIG. 26A, the light measurement is performed on the well 21 in which the light sources 12a ′ are arranged to face each other, and in the second light measurement, the first light measurement is performed as shown in FIG. 26B. The light measurement is performed on the well 21 for which the light measurement has not been performed in the above light measurement. Note that, in FIG. 26B, the black-painted well 21 ′ is the well in which the light measurement was performed the first time.
With such a configuration, it is possible to appropriately deal with the optical measurement of the microplate 20 having a large number of wells, for example, the 1536 wells in which the pitch of the wells 21 is 2.25 mm.

  Further, in the microplate reader 10D, since it is only necessary to switch the position of the microplate 20 between two positions, complicated control such as position control of a motor is not required, and the moving mechanism is inexpensively configured with a simple actuator. be able to.

The above microplate reader 10D can be used, for example, in an incubator (incubator).
The incubator has a storage space (culture space) for storing a culture container therein. In general, a plurality of shelves are horizontally arranged in the accommodation space while being vertically separated from each other, and the culture vessels are placed on these shelves. Therefore, in order to increase the number of shelves, the microplate reader used in the incubator needs to be thin.
Also, in the incubator, we do not want to give external stimulation (vibration) to the cells (stem cells, etc.) in the wells as much as possible.

As described above, since the microplate reader 10D moves only in the one-axis direction, it is possible to provide a device configuration that does not increase in the height direction. Further, since the microplate reader 10D moves only between two positions, it is possible to limit the scanning to a minimum level without giving a stimulus such as vibration or vibration as much as possible.
Therefore, the microplate reader 10D can be a microplate reader suitable for use in the incubator.

  Although a specific embodiment has been described above, the embodiment is merely an example and is not intended to limit the scope of the present invention. The devices and methods described herein may be embodied in forms other than those described above. In addition, omissions, substitutions, and changes can be appropriately made to the above-described embodiment without departing from the scope of the present invention. The forms with such omissions, substitutions, and changes are included in the scope of the claims and equivalents thereof, and belong to the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 10 ... Microplate reader, 11a ... Light projecting substrate, 11b ... Measuring substrate, 11c ... Aperture part, 12a ... Light source, 12b ... Photosensor, 13 ... Light guide plate part, 13a ... Light receiving light guide path, 14 ... Mirror Plate, 14a ... Reflective surface, 15 ... Housing, 18 ... Microplate reader unit, 20 ... Microplate, 21 ... Well

Claims (20)

A housing,
A light projecting unit which is arranged on one side of a microplate having a plurality of wells arranged therein and which corresponds to one well of the microplate;
A light-receiving unit arranged on the one side of the microplate and corresponding to one well of the microplate;
The light, which is arranged on the opposite side of the light projecting unit and the light receiving unit with the microplate interposed therebetween, passes light passing through the sample contained in the well from the light projecting unit and the light receiving unit, and the light projecting unit and A reflecting member for reflecting to the light receiving portion side,
A light receiving light guide path that is disposed between the light projecting portion and the light receiving portion, and that guides the light reflected by the reflecting member and passing through the sample to the light receiving portion,
A plurality of sets of the light projecting unit, the light receiving unit, and the light receiving light guide path corresponding to one well are provided,
A plurality of the light receiving light guide paths, a light guide section surrounded by a surrounding member made of a pigment-containing resin containing a pigment having a property of absorbing light,
The microplate reader further comprising: a limiting unit that limits an angular component of light incident on the light receiving unit.   The set of the light projecting section, the light receiving section, and the light receiving light guide path corresponding to the one well is provided at least by the number of wells of the microplate. Microplate reader. The number of sets of the light projecting unit, the light receiving unit, and the light receiving light guide path corresponding to the one well is less than the number of wells of the microplate,
A moving mechanism that sequentially moves the microplate relative to the set of the light projecting unit, the light receiving unit, and the light receiving guide path so as to correspond to all the wells of the microplate. The microplate reader according to claim 1, which is characterized in that. A set of the light projecting portion, the light receiving portion, and the light receiving light guide path corresponding to the one well is provided by the number of wells on one side of the microplate,
The moving mechanism sequentially moves the microplate relative to a set of the light projecting unit, the light receiving unit, and the light receiving light guide path only in a direction orthogonal to the one side. The microplate reader according to claim 3. A light projecting substrate provided with a plurality of the light projecting portions;
An aperture part provided on the light projecting substrate corresponding to one well of the microplate, allowing the light reflected by the reflecting member and having passed through the sample to pass through and to enter the light receiving waveguide. Prepare,
The restriction unit is
The microplate reader according to any one of claims 1 to 4, wherein the aperture portion is smaller than an opening at a light incident end of the light receiving light guide path. The restriction unit is
The micro member according to any one of claims 1 to 5, wherein the reflecting member is selectively provided on a surface facing the micro plate according to a position where the light guide path for receiving light is formed. Plate reader. The reflective member is selectively provided on one substrate,
The microplate reader according to claim 6, wherein at least a part of the area of the substrate where the reflection member is not provided is AR-coated. The reflective member is selectively provided on one substrate,
7. A light absorbing member made of a pigment-containing resin containing a pigment having a property of absorbing light is provided in at least a part of a region of the substrate where the reflecting member is not provided. Microplate reader as described. The restriction unit is
9. The microplate reader according to claim 1, wherein the microplate reader is a condensing lens that condenses light emitted from the light projecting unit. The light guide section is arranged above the light receiving section,
The light projecting unit is disposed above the light guide unit,
The microplate reader according to claim 1, wherein the reflecting member is arranged above the microplate arranged above the light projecting unit. A light projecting substrate having a plurality of power supply circuits to the light projecting section, wherein the light projecting section is electrically connected;
A light-receiving substrate having a plurality of power feeding circuits to the light-receiving unit, the light-receiving unit is electrically connected,
An aperture part provided on the light projecting substrate corresponding to one well of the microplate, allowing the light reflected by the reflecting member and having passed through the sample to pass through and to enter the light receiving waveguide. The microplate reader according to any one of claims 1 to 7, further comprising:   12. The microplate reader according to claim 1, wherein the light projecting unit is a light emitting diode.   13. The microplate reader according to claim 1, wherein the light receiving section is a light receiving sensor.   13. The microplate reader according to claim 1, wherein the light receiving section is an optical fiber.   The microplate reader according to any one of claims 1 to 14, wherein at least a part of the light receiving light guide path is filled with a resin having a light-transmitting property that constitutes the pigment-containing resin. .   16. The micro according to claim 1, wherein the light receiving light guide path is made of a resin having a light transmitting property, and includes a flat portion and a columnar member extending in a columnar shape from the flat portion. Plate reader.   17. A step portion is provided at a connecting portion between the flat portion and the columnar member so that a diameter of the connecting portion side is larger than a diameter of a tip portion side of the columnar member. The microplate reader described in 1. A light emitting unit and a light receiving unit respectively corresponding to one well of the microplate,
The light emitted from the light projecting part, which has passed through the sample contained in the corresponding well, is folded back and again passes through the sample, and the light receiving light guide path for guiding the light to the light receiving part and the light receiving guide path. A light guide section having an enclosing member that encloses the optical path with a pigment-containing resin that contains a pigment having a property of absorbing light,
A microplate reader unit comprising: a limiting unit that limits an angular component of light incident on the light receiving unit.   19. The microplate reader unit according to claim 18, wherein the light receiving light guide path is made of a resin having a light transmitting property, and includes a flat portion and a columnar member extending in a columnar shape from the flat portion. 20. A stepped portion is provided at a connecting portion between the flat portion and the columnar member such that a diameter on the connecting portion side is larger than a diameter on a tip end side of the columnar member. The microplate reader unit described in.

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