This application claims the benefit under 35 U.S.C. § 371 as a U.S. National Stage Entry of International Application No. PCT/JP2020/039885, filed in the Japanese Patent Office as a Receiving Office on Oct. 23, 2020, which claims priority to Japanese Patent Application Number 2019-201744, filed in the Japanese Patent Office on Nov. 6, 2019, each of which is hereby incorporated by reference in its entirety.
The present disclosure relates to an optical measurement apparatus and an information processing system.
Conventionally, optical measurement methods using flow cytometry are used in the analysis of living-body related particles such as cells, microorganisms, and liposomes. A flow cytometer is an apparatus for carrying out optical measurement using flow cytometry which radiates light to the particles flowing in a flow channel formed in a flow cell, a microchip, or the like and executes analysis or the like by detecting fluorescence or scattered light emitted from each of the particles.
The flow cytometer includes, for example, an analyzer for analyzing a sample and a sorter provided with a function to analyze a sample and sort and collect only the particles having particular characteristics based on the analysis result. Also, a sorter which uses cells as samples and is provided with a function to sort and collect the cells based on analysis results is also called “cell sorter”.
Also, recently, based on demands from basic medicine and clinical discipline, flow cytometers capable of carrying out multicolor analysis using plural fluorescent pigments have been developed. The flow cytometers capable of carrying out multicolor analysis include multichannel-type and spectrum-type flow cytometers. In the multichannel-type or spectrum-type flow cytometer, fluorescence emitted from particles in a particular direction is separated by a spectroscopy optical system and enters an array light detector.
However, there has been a problem that an overall apparatus including an optical system becomes large to enable multicolor analysis, for example, since plural excitation light source have to be provided.
Therefore, the present disclosure proposes an optical measurement apparatus and an information processing system which enable multicolor analysis while suppressing increase in size.
To solve the above-described problem, an optical measurement apparatus according to one aspect of the present disclosure comprises: an excitation light source that emits excitation light; a waveguide optical system that guides the excitation light to a predetermined position along a predetermined light path; a fluorescence detection system that detects fluorescence radiated from a particle by excitation of the particle present at the predetermined position by the excitation light; and a first scattered-light detection system that detects first scattered light generated by scattering of the excitation light by the particle present at the predetermined position, wherein the waveguide optical system includes a separation optical system that separates the fluorescence and the first scattered light among the light emitted in a predetermined direction from the predetermined position, the fluorescence detection system detects the fluorescence separated by the separation optical system, and the first scattered-light detection system detects the first scattered light separated by the separation optical system.
Hereinafter, an embodiment of the present disclosure will be described in detail based on drawings. In the following embodiment, the same parts are denoted by the same reference signs to omit redundant descriptions.
Also, the present disclosure is described in accordance with the order of items shown below.
1. Overall Configuration of Apparatus
1.1 Rough Configuration Example of Optical System
1.2 Rough Configuration Example of Information Processing System
1.3 Timing Control Example Using Forward-scattered Light
1.4 About Alignment
2. Rough Configuration of Microchip
3. Effects of Separating Fluorescence and Backscattered Light by Using Dichroic Mirror
1. Overall Configuration of Apparatus
First, an overall configuration of an optical measurement apparatus according to the present embodiment will be described in detail with reference to drawings. Note that, in the present embodiment, a cell analysis apparatus is shown as an example of the optical measurement apparatus. The cell analysis apparatus according to the present embodiment may be, for example, a flow cytometer.
Also, in the present embodiment, a microchip method is shown as an example of a supplying method of microparticles to an observation point (hereinafter, referred to as a spot) on a flow channel. However, the supplying method is not limited thereto, and, for example, any of various methods such as a droplet method, a cuvette method, and a flow cell method can be employed. Furthermore, techniques according to the present disclosure are not limited to a cell sorter, but can be applied to various optical measurement apparatuses, which measure microparticles passing through a spot set on a flow channel, such as an analyzer-type flow cytometer and a microscope which obtains images of microparticles on a flow channel.
1.1 Rough Configuration Example of Optical System
In this configuration, the total reflection mirror 111, the dichroic mirrors 112 and 113, the perforated mirror 114, and the dichroic mirror 115 constitute a waveguide optical system which guides excitation light L1 to L3, which has been emitted from the excitation light sources 101 to 103, to a predetermined light path. Among these, the dichroic mirror 115 forms a separation optical system, which separates fluorescence (for example, fluorescence L14) and scattered light (for example, backscattered light L12) from the light emitted in a predetermined direction (for example, to the back) from a spot 123a set on a flow channel in the microchip 120. Also, the perforated mirror 114 constitutes a reflection optical system which reflects the scattered light (for example, the backscattered light L12), which has been separated by the above described separation optical system, to a light path (for example, a light path toward the later-described backscattered-light detection system 130) different from the above described predetermined light path.
Also, the objective lens 116 constitutes a condensing optical system which condenses the excitation light L1 to L3, which has propagated through the above described predetermined light path, onto the spot 123a set on the flow channel in the microchip 120. Note that the number of the spot (s) 123a is not limited to one. Therefore, each of the excitation light L1 to L3 may be condensed at a different spot. Also, the condensing positions of the excitation light L1 to L3 are not required to be the same as the spot (s) 123a, but may be shifted therefrom.
In the example illustrated in
The total reflection mirror 111 may be, for example, a total reflection mirror which reflects the excitation light L1, which has been emitted from the excitation light source 101, toward a predetermined direction.
The dichroic mirror 112 is an optical element for causing an optical axis of the excitation light L1 reflected by the total reflection mirror 111 and an optical axis of the excitation light L2 emitted from the excitation light source 102 to match or be parallel to each other. The dichroic mirror 112, for example, allows the excitation light L1, which is from the total reflection mirror 111, to transmit therethrough and reflects the excitation light L2, which is from the excitation light source 102. As this dichroic mirror 112, for example, a dichroic mirror designed to allow transmission of the light having a wavelength of 637 nm and reflect the light having a wavelength of 488 nm may be used.
The dichroic mirror 113 is an optical element for causing optical axes of the excitation light L1 and L2 from the dichroic mirror 112 and an optical axis of the excitation light L3 emitted from the excitation light source 103 to match or be parallel to each other. The dichroic mirror 113, for example, allows the excitation light L1, which is from the total reflection mirror 111, to transmit therethrough and reflects the excitation light L3, which is from the excitation light source 103. As this dichroic mirror 113, for example, a dichroic mirror designed to allow transmission of the light having a wavelength of 637 nm and the light having a wavelength of 488 nm and reflect the light having a wavelength of 405 nm may be used.
The excitation light L1 to L3, which has been finally collected by the dichroic mirror 113 as the light which travels in the same direction, enters the dichroic mirror 115 via a hole 114a provided in the perforated mirror 114.
Herein, the shape of the perforated mirror will be described by using
As illustrated in
As illustrated in
Also, as illustrated in
For example, a numerical aperture NA of the collected excitation light L1 to L3 is 0.15, the numerical aperture of the hole 114a viewed from the direction tilted by the angle θ is only required to be 0.15 or higher. However, in a case in which the hole 114a is too large, the numerical aperture of the hole 114a is preferred to be as small as possible since the backscattered light L12, which enters the backscattered-light detection system 130, is reduced.
Note that the shape of the reflection surface of the perforated mirror 114 and the shape of the hole 114a are not limited to circular shapes, but may be oval shapes, polygonal shapes, etc. Furthermore, the shape of the reflection surface of the perforated mirror 114 and the shape of the hole 114a do not have to be similar to each other, but may have shapes which are independent from each other.
Returning to
Note that, on the light path from the excitation light sources 101 to 103 to the objective lens 116, a beam shaping unit for converting the excitation light L1 to L3 to parallel light may be provided. The beam shaping unit may include, for example, one or more lense (s) or mirror (s).
The objective lens 116 condenses the entered excitation light L1 to L3 at the predetermined spot 123a on the flow channel in the later-described microchip 120. When the spot 123a is irradiated with the excitation light L1 to L3, which is pulsed light, while microparticles are passing through the spot 123a, fluorescence is radiated from the microparticles, the excitation light L1 to L3 is scattered by the microparticles, and scattered light is generated.
In the present description, among the scattered light generated in all directions from the microparticles, the components within a predetermined angular range traveling forward in the traveling directions of the excitation light L1 to L3 are referred to as forward-scattered light, the components within a predetermined angular range traveling backward in the traveling direction of the excitation light L1 to L3 are referred to as backscattered light L12, and the components in the directions not within predetermined angles from the optical axes of the excitation light L1 to L3 are referred to as side-scattered light.
The objective lens 116, for example, has a numerical aperture corresponding to about 30 degrees to 40 degrees (for example, corresponding to the above described predetermined angle) with respect to the optical axis. The components (hereinafter, referred to as fluorescence L14) within the predetermined angular range traveling backward in the traveling direction of the excitation light L1 to L3 among the fluorescence radiated from the microparticles and the backscattered light L12 transmit through the objective lens 116 and enters the dichroic mirror 115.
Among the fluorescence L14 and the backscattered light L12 which has entered the dichroic mirror 115, the fluorescence L14 transmits through the dichroic mirror 115 and enters the fluorescence detection system 140.
On the other hand, the backscattered light L12 is reflected by the dichroic mirror 115, is further reflected by the perforated mirror 114, and enters the backscattered-light detection system 130. Herein, the numerical aperture of the hole 114a of the perforated mirror 114 is assumed to be a numerical aperture of about 20 degrees (for example, NA≈0.2) with respect to the optical axis, and the numerical aperture of the objective lens 116 is assumed to be a numerical aperture of about 40 degrees with respect to the optical axis. In such a case, the backscattered light L12 within an angular range of about 20 degrees to 40 degrees with respect to the optical axis enters the backscattered-light detection system 130. In other words, the backscattered light L12 having a donut-shaped beam profile enters the backscattered-light detection system 130.
The backscattered-light detection system 130 is provided with, for example: plural lenses 131, 133, and 135 which shape the beam cross section of the backscattered light L12 reflected by the perforated mirror 114; a diaphragm 132 which adjusts the light intensity of the backscattered light L12; a mask 134 which selectively allows transmission of the light having particular wavelengths (for example, the light having a wavelength of 488 nm corresponding to the excitation light L2) among the backscattered light L12; and a light detector 136 which detects the light which has transmitted through the mask 134 and the lens 135 and entered.
The diaphragm 132 may for example have a configuration of a light-shielding plate provided with a pinhole-like hole. This hole is only required to be larger than the width of the center-part hole (area in which laser intensity is low) of the backscattered light L12 having the donut-shaped beam profile.
The light detector 136 includes, for example, a two-dimensional image sensor, a photodiode, or the like and detects the light intensity and size of the light which has transmitted through the mask 134 and the lens 135 and entered. Signals detected by the light detector 136 are input to, for example, a later-described analysis system 212. Note that, in the analysis system 212, for example, the size, etc. of microparticles may be analyzed based on the input signals.
The fluorescence detection system 140 is provided with, for example, a spectroscopy optical system 141, which separates the entered fluorescence L14 into dispersed light L15, and a light detector 142, which detects the light intensity of the dispersed light L15 of each predetermined wavelength band (in other words, channel).
Herein,
Returning to
The signals indicating the light intensity of the fluorescence L14 of each channel detected by the light detector 142 are input to, for example, the later-described analysis system 212. Note that, in the analysis system 212, for example, component analysis, morphology analysis, etc. of microparticles may be executed based on the input signals.
1.2 Rough Configuration Example of Information Processing System
1.3 Timing Control Example Using Forward-Scattered Light
Returning to
Light L16 traveling forward in the traveling direction of the excitation light L1 to L3 from the microparticles includes forward-scattered light and the components within a predetermined angular range which travels forward in the traveling direction of the excitation light L1 to L3 among the fluorescence radiated from the microparticles. The filter 151, which is disposed in a downstream side compared with the microchip 120 in the light path of the excitation light L1 to L3, selectively allows transmission of, for example, the light (forward-scattered light L17) having a wavelength 637 nm corresponding to the excitation light L1 and the light (forward-scattered light L18) having a wavelength of 488 nm corresponding to the excitation light L2 among these light components and blocks the light of other wavelengths.
The forward-scattered light L17 and L18, which has passed through the filter 151, is converted to parallel light when the light passes through the collimator lens 152. Then, the light is reflected in a predetermined direction by the total reflection mirror 153 and enters the forward-scattered-light detection system 160.
The forward-scattered-light detection system 160 is provided with a lens 161, a dichroic mirror 162a, a total reflection mirror 162b, diaphragms 163a and 163b, lenses 164a and 164b, filters 165a and 165b, diffraction grating 166a and 166b, light detectors 167a and 167b.
The dichroic mirror 162a is designed to reflect the forward-scattered light L17, which is the scattered light of the excitation light L1, and allows transmission of the forward-scattered light L18, which is the scattered light of the excitation light L2, among the forward-scattered light L17 and L18 reflected by the total reflection mirror 153.
The lens 161 and the lens 164a function as an optical system which shapes the beam cross section of the forward-scattered light L17 which travels in the light path sandwiched therebetween. The diaphragm 163a adjusts the light intensity of the forward-scattered light L17, which enters the light detector 167a. The filter 165a and the diffraction grating 166a function as an optical filter which increases the degree of purity of the forward-scattered light L17 in the light which enters the light detector 167a. The light detector 167a, for example, includes a photodiode and detects the entrance of the forward-scattered light L17.
Similarly, the lens 161 and the lens 164b function as an optical system which shapes the beam cross section of the forward-scattered light L18 which travels in the light path sandwiched therebetween. The diaphragm 163b adjusts the light intensity of the forward-scattered light L18, which enters the light detector 167b. The filter 165b and the diffraction grating 166b function as an optical filter which increases the degree of purity of the forward-scattered light L18 in the light which enters the light detector 167b. The light detector 167b, for example, includes a photodiode and detects the entrance of the forward-scattered light L18.
In this manner, as a configuration for detecting forward-scattered light, the present embodiment is provided with two systems, i.e., the detection system (the lenses 161 and 164a, the diaphragm 163a, the filter 165a, the diffraction grating 166a, and the light detector 167a) which detects the forward-scattered light L17 and the detection system (the lenses 161 and 164b, the diaphragm 163b, the filter 165b, the diffraction grating 166b, and the light detector 167b) which detects the forward-scattered light L18. In such a case, the timing detected by either one of the detection systems (for example, the detection system which detects the forward-scattered light L18) can be compensated for by the timing detected by the other detection system (for example, the detection system which detects the forward-scattered light L17). However, the configuration is not limited to such a configuration. For example, either one of the detection systems may be omitted. Note that the timing referred to herein may be the timing at which the microparticles pass through the spot 123a set on the flow channel in the microchip 120.
1.4 About Alignment
Note that, in the above configuration, the optical system for irradiating the spot 123a with the excitation light L1 to L3 and the detection system for detecting the fluorescence L14 and the backscattered light L12 from the spot 123a, in other words, the excitation light sources 101 to 103, the total reflection mirror 111, the dichroic mirrors 112 and 113, the perforated mirror 114, the dichroic mirror 115, and the objective lens 116 may be mounted on a single base 100. Also, the detection system for detecting the forward-scattered light L17 and L18 from the spot 123a, in other words, the backscattered-light detection system 130, the fluorescence detection system 140, the filter 151, the total reflection mirror 153, and the forward-scattered-light detection system 160 may be mounted on a single base 150, which is different from the base 100. Furthermore, the base 100 and the base 150 may be able to carry out alignment with each other.
2. Rough Configuration of Microchip
Subsequently, the microchip according to the present embodiment will be described.
The sheath-solution introducing flow channels 122a and 122b converge with the sample-solution introducing flow channel 121 from both sides, and one converging flow channel 123 is provided in the downstream side of the converging point thereof. In the converging flow channel 123, the circumference of the sample solution 126 is surrounded by a sheath solution 127 so that the solution flows in a state in which a laminar flow is formed. By virtue of this, the microparticles in the sample solution 126 flow while the microparticles are arranged approximately in one row with respect to the flow direction.
On the other hand, at a downstream-side end of the converging flow channel 123, a negative-pressure suction unit 124 for sorting the microparticles serving as collection objects and disposal flow channels 125a and 125b for discharging microparticles, etc. which are not the collection objects are provided. All of these are communicated with the converging flow channel 123. Note that downstream-side ends of the disposal flow channels 125a and 125b are coupled to, for example, a waste solution tank or the like. In the microchip 120, individual microparticles are detected in the converging flow channel 123, only the microparticles which have been determined to be the collection objects as a result are pulled into the negative-pressure suction unit 124, and the microparticles other than those are discharged from the disposal flow channels 125a and 125b.
The configuration of the negative-pressure suction unit 124 is not particularly limited as long as the microparticles serving as collection objects can be suctioned at predetermined timing. For example, as illustrated in
Also, the pressure chamber 124b is coupled to the actuator 124c such as a piezoelectric element via a vibration plate.
Examples of the material that forms the microchip 120 includes polycarbonate, cycloolefin polymer, polypropylene, polydimethylsiloxane (PDMS), glass, and silicon. Particularly, polymer materials such as polycarbonate, cycloolefin polymer, and polypropylene are preferred to be used for formation since these are excellent in processability and can be duplicated at low cost by using a molding apparatus. In this manner, by employing the configuration in which plastic molded substrates are pasted to each other, the microchip 120 can be manufactured at low cost.
Note that, as described above, the method of supplying the microparticles to the spot on the flow channel in the present embodiment is not limited to the microchip method, but various methods such as a droplet method, a cuvette method, and a flow cell method can be employed.
3. Effects of Separating Fluorescence and Backscattered Light by Using Dichroic Mirror
Subsequently, effects of separating the fluorescence L14 and the backscattered light L12 by using the dichroic mirror 115 will be described.
As illustrated in
If the fluorescence L14 and the backscattered light L12 is not separated from each other in this manner, the fluorescence L14 in the vicinity of the optical axis having a comparatively high beam intensity goes through the hole 114a of the perforated mirror 114. Therefore, the sensitivity of the detection system with respect to the fluorescence L14 is lowered, and the detection efficiency and detection accuracy is lowered. Note that the fluorescence L14 and the backscattered light L12, which has gone through the hole 114a, may be absorbed, for example, by a beam damper, which is not illustrated.
On the other hand, when the fluorescence L14 and the backscattered light L12 is configured to be separated from each other by the dichroic mirror 115 before reflecting by the perforated mirror 114 like the present embodiment illustrated in
Hereinabove, the embodiment of the present disclosure has been described. However, the technical scope of the present disclosure is not limited to the above described embodiment without change, but various changes can be made within the scope not deviating from the gist of the present disclosure. Also, constituent elements of different embodiments and modification examples may be arbitrarily combined.
Also, the effects of the embodiments described in the present specification are merely examples, but are not limitative, and other effects may be exerted.
The present techniques can also employ following configurations.
(1)
An optical measurement apparatus comprising:
The optical measurement apparatus according to (1), wherein the separation optical system is a dichroic mirror.
(3)
The optical measurement apparatus according to (1) or (2), wherein
The optical measurement apparatus according to (3), wherein the separation optical system reflects the excitation light propagated along the predetermined light path and, among the light propagated along the predetermined light path from the predetermined position, allows transmission of the fluorescence and reflects the first scattered light.
(5)
The optical measurement apparatus according to (4), wherein
The optical measurement apparatus according to any one of (1) to (5), wherein
The optical measurement apparatus according to any one of (1) to (6), further comprising:
The optical measurement apparatus according to any one of (1) to (8), further comprising a condensing optical system that condenses, onto a predetermined position on a flow channel, the excitation light propagated on the predetermined light path.
(9)
An information processing system comprising:
The information processing system according to (9), further comprising a sorting mechanism that selectively sorts the particle based on an analysis result by the analysis unit, the particle having been passed through the predetermined position.
Number | Date | Country | Kind |
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2019-201744 | Nov 2019 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2020/039885 | 10/23/2020 | WO |
Publishing Document | Publishing Date | Country | Kind |
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WO2021/090708 | 5/14/2021 | WO | A |
Number | Name | Date | Kind |
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20130338479 | Pogue et al. | Dec 2013 | A1 |
20170350806 | Sinha | Dec 2017 | A1 |
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2056090 | May 2009 | EP |
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2008-241361 | Oct 2008 | JP |
2009-145213 | Jul 2009 | JP |
2012-127922 | Jul 2012 | JP |
2018-105685 | Jul 2018 | JP |
2016185623 | Nov 2016 | WO |
2019167510 | Sep 2019 | WO |
Entry |
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International Written Opinion and English translation thereof mailed Dec. 28, 2020 in connection with International Application No. PCT/JP2020/039885. |
International Preliminary Report on Patentability and English translation thereof mailed May 19, 2022 in connection with International Application No. PCT/JP2020/039885. |
Extended European Search Report issued Aug. 30, 2023 in connection with European Application No. 20885128.7. |
PCT/JP2020/039885, date of mailing Dec. 28, 2020, International Search Report. |
International Search Report and English translation thereof mailed Dec. 28, 2020 in connection with International Application No. PCT/JP2020/039885. |
Number | Date | Country | |
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20230349809 A1 | Nov 2023 | US |