Sensor connector and measurement method

Abstract

The present invention provides a sensor connector and a measurement method that can reduce the risk of being unable to obtain sufficient light intensity for measurement to acquire physical property data suitable for analysis. [Solution] A sensor connector that irradiates a sample containing a substance to be measured for physical property data with measurement light incident from a spectroscopic analyzer, captures the reflected light from the sample and outputs it to the spectroscopic analyzer, and has an optical system in which the output surface of the measurement light in contact with the sample is flat.

Description

Technical Field

[0001] The technology of the present disclosure relates to a sensor unit connector and a measurement method.

Background Art

[0002] There is known a flow cell having a flow path through which a fluid flows and being used for measuring physical property data of substances present in the fluid. Some flow cells have an optical system that condenses measurement light for physical property data and captures return light from the substance irradiated with the measurement light. Note that the fluid is, for example, a cell culture solution containing a cell product such as an antibody as a substance, and the physical property data is, for example, Raman spectrum data.

[0003] Japanese Patent Publication No. 2020-511635 discloses a flow cell including a ball lens as an optical system. The ball lens is disposed in an orifice provided in a wall surface forming the flow path. The emission surface of the measurement light of the ball lens is in contact with the fluid flowing through the flow path.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Japanese Patent Publication No. 2020-511635, as described above, a ball lens having a refractive power on the emission surface is used as the optical system. For this reason, the condensing position of the measurement light is away from the emission surface of the ball lens in contact with the fluid. That is, a fluid intervenes between the emission surface of the ball lens and the condensing position of the measurement light. Therefore, there has been a possibility that the measurement light is attenuated by the fluid and the amount of light necessary for obtaining physical property data that can withstand analysis cannot be obtained. This problem becomes more prominent in the case of a fluid having a relatively high turbidity such as a cell culture solution.

[0005] One embodiment according to the technology of the present disclosure provides a sensor unit connector and a measurement method capable of reducing the possibility of not being able to obtain the amount of light of measurement light necessary for obtaining physical property data that can withstand analysis.

Means for Solving the Problems

[0006] The flow cell of this disclosure comprises a main body having a channel through which a fluid containing a substance to be measured for physical property data flows, and an optical system disposed in a part of the wall surface forming the channel and for collecting measurement light for physical property data, wherein the emission surface of the measurement light in contact with the fluid is flat.

[0007] The optical system preferably includes a lens with positive refractive power and an optical element whose surface that emits the measurement light in contact with the fluid is planar.

[0008] The lens is preferably one of the following: a ball lens, a hemispherical lens, or a cylindrical lens.

[0009] If the lens is a cylindrical lens, it is preferable that the cylindrical lens focuses the measurement light in a linear manner parallel or perpendicular to the direction of fluid flow.

[0010] The optical element is preferably a transparent plate in which the surface of the measurement light that comes into contact with the fluid and the surface of the measurement light that is on the opposite side of the surface of the measurement light that comes into contact with the fluid are parallel.

[0011] The thickness of the optical element in the direction of the optical axis is preferably less than or equal to the distance between the point where the optical axis intersects the lens's output surface and the point where the measurement light is collected.

[0012] The thickness is preferably more than half the distance.

[0013] The thickness is the same as the distance, and the light-gathering position is preferably located on the emission surface of the optical element.

[0014] The thickness is preferably between 0.3 mm and 7.5 mm.

[0015] It is preferable that the curvature of the exit surface of the lens and the incident surface of the optical element are the same. Furthermore, it is preferable that the exit surface of the lens and the incident surface of the optical element are joined together.

[0016] A connector to which an optical analyzer for outputting physical property data is connected, and it is preferable that a connector having a lens disposed at its tip is provided detachably on the main body.

[0017] The optical system preferably includes a lens having a positive refractive power and a flat emission surface of the measurement light that contacts the fluid.

[0018] The lens is preferably either a hemispherical lens or a cylindrical lens.

[0019] When the lens is a cylindrical lens, the cylindrical lens preferably condenses the measurement light linearly parallel or perpendicular to the direction in which the fluid flows.

[0020] The wall surface is preferably a smooth surface.

[0021] The turbidity of the fluid is preferably 250 NTU or more and 1000 NTU or less.

[0022] The physical property data is preferably Raman spectrum data.

[0023] The measurement method of the present disclosure measures physical property data using the flow cell described above.

[0024] The fluid is preferably a cell culture solution. In this case, the cell culture solution preferably contains a cell product as a substance.

[0025] The cell culture solution is preferably obtained from a culture tank during culture. Also, the cell culture solution is preferably one from which cells have been removed.

Effect of the Invention

[0026] According to the technology of the present disclosure, it is possible to provide a sensor unit connector and a measurement method capable of reducing the risk of not being able to obtain the amount of light of the measurement light for obtaining physical property data that can withstand analysis.

Brief Description of the Drawings

[0027] [Figure 1] It is a diagram showing a state where Raman spectrum data of substances present in a cell culture solution obtained from a culture tank during culture is being measured. [Figure 2] It is a perspective view of a flow cell. [Figure 3] It is an exploded cross-sectional view of a flow cell. [Figure 4] It is an exploded perspective view of a transparent plate, an O-ring, and a plate retainer. [Figure 5] It is a cross-sectional view of a flow cell. [Figure 6] It is a cross-sectional view of a flow cell. [Figure 7] It is a diagram showing another example of the positional relationship between a ball lens and a transparent plate. [Figure 8] It is a diagram showing another example of an optical element. [Figure 9] It is a diagram showing an optical system including a hemispherical lens and a transparent plate. [Figure 10] It is a diagram showing an optical system including a plano-convex lens and a transparent plate. [Figure 11] It is a diagram showing an optical system including an aspherical plano-convex lens and a transparent plate. [Figure 12] It is a diagram showing an optical system including a cylindrical lens and a transparent plate. [Figure 13] It is a diagram showing an example in which excitation light is condensed linearly parallel to the direction in which the culture supernatant flows by a cylindrical lens. [Figure 14] It is a diagram showing an example in which excitation light is condensed linearly perpendicular to the direction in which the culture supernatant flows by a cylindrical lens. [Figure 15] It is a diagram showing an example using only a hemispherical lens. [Figure 16] It is a diagram showing an example in which excitation light is condensed linearly parallel to the direction in which the culture supernatant flows by a cylindrical lens. [Figure 17] It is a diagram showing an example in which excitation light is condensed linearly perpendicular to the direction in which the culture supernatant flows by a cylindrical lens. [Figure 18] This figure shows an optical system composed solely of plano-convex lenses, as shown in Figure 10. [Figure 19] This figure shows an optical system composed solely of plano-convex lenses, as shown in Figure 11. [Figure 20] This figure shows an optical system in which the hemispherical lens and the transparent plate shown in Figure 9 are integrally formed as a single lens. [Figure 21] This table summarizes the conditions and evaluation criteria for the examples and comparative examples. [Modes for carrying out the invention]

[0028] [First Embodiment] As an example, as shown in Figure 1, the measurement system 2 comprises a flow cell 10 and a Raman spectrometer 11. The measurement system 2 is incorporated, for example, into a cell culture section 12 in a biopharmaceutical active pharmaceutical ingredient manufacturing system. The cell culture section 12 has a culture vessel 13 and a cell removal filter 14. Cell culture medium 15 is stored in the culture vessel 13.

[0029] Antibody-producing cells 16 are seeded in the culture tank 13 and cultured in the cell culture medium 15. Antibody-producing cells 16 are cells established by incorporating antibody genes into host cells, such as Chinese hamster ovary cells (CHO (Chinese Hamster Ovary) cells). Antibody-producing cells 16 produce immunoglobulins, i.e., antibodies 17, during the culture process. Therefore, not only antibody-producing cells 16 but also antibodies 17 are present in the cell culture medium 15. Antibody 17 is, for example, a monoclonal antibody and serves as an active ingredient in a biopharmaceutical. Antibody 17 is an example of the "substance" and "cell product" related to the technology disclosed herein.

[0030] A first discharge channel 18 is connected to the culture vessel 13. A cell decontamination filter 14 is provided in the first discharge channel 18. The cell decontamination filter 14 captures antibody-producing cells 16 in the cell culture medium 15 using a filter membrane (not shown) by means of, for example, tangential flow filtration (TFF), and removes the antibody-producing cells 16 from the cell culture medium 15. The cell decontamination filter 14 is also permeable to antibodies 17. Therefore, the cell culture medium 15, mainly containing antibodies 17, flows downstream of the cell decontamination filter 14 in the first discharge channel 18. The cell culture medium 15 from which antibody-producing cells 16 have been removed by the cell decontamination filter 14 is called the culture supernatant. Hereinafter, the cell culture medium 15 from which antibody-producing cells 16 have been removed by the cell decontamination filter 14 will be referred to as the culture supernatant 15A. The culture supernatant 15A is an example of the "fluid" related to the technology of this disclosure.

[0031] The turbidity of culture supernatant 15A is between 250 NTU (Nephelometric Turbidity Unit) and 1000 NTU. NTU is a unit of liquid turbidity based on the Formazin standard solution.

[0032] Furthermore, the culture supernatant 15A contains, in addition to antibody 17, impurities such as cell-derived proteins, cell-derived DNA (deoxyribonucleic acid), and aggregates of antibody 17, as well as viruses, etc. These impurities are also examples of "substances" and "cell products" related to the technology disclosed herein. Similarly, viruses, etc., are also examples of "substances" related to the technology disclosed herein.

[0033] The flow cell 10 is connected to the first discharge channel 18 downstream of the cell-decontaminated filter 14. Culture supernatant 15A from the first discharge channel 18 flows through the flow cell 10 as indicated by arrow FD. A discharge pump (not shown) is provided downstream of the cell-decontaminated filter 14 in the first discharge channel 18 (between the cell-decontaminated filter 14 and the flow cell 10). The discharge pump delivers the culture supernatant 15A to the flow cell 10 at a flow rate of 200 cc / min or more, for example, 300 cc / min.

[0034] A second discharge channel 19 is also connected to the flow cell 10. The culture supernatant 15A that flows into the flow cell 10 from the first discharge channel 18 flows out into the second discharge channel 19. The second discharge channel 19 is connected to a purification unit, for example, which purifies antibody 17 from the culture supernatant 15A using a chromatography apparatus, and sends the culture supernatant 15A from the flow cell 10 to the purification unit. Alternatively, the first discharge channel 18 may be connected to the purification unit, and a branching channel may be provided downstream of the cell-decontaminated filter 14 of the first discharge channel 18. Then, the flow cell 10 may be connected to the branching channel, and the culture supernatant 15A that has flowed through the flow cell 10 may be discarded. Alternatively, the second discharge channel 19 may be connected to a culture tank 13, and the culture supernatant 15A that has flowed through the flow cell 10 may be returned to the culture tank 13.

[0035] The Raman spectrometer 11 is an instrument that evaluates materials using the characteristics of Raman scattered light, and is an example of an "optical analysis device" related to the technology of this disclosure. When excitation light EL (see Figure 6) is irradiated onto a material, the excitation light EL interacts with the material, generating Raman scattered light with a different wavelength from the excitation light EL. The wavelength difference between the excitation light EL and the Raman scattered light corresponds to the energy of the molecular vibrations of the material. Therefore, Raman scattered light with different wavenumbers can be obtained between materials with different molecular structures. The excitation light EL is an example of a "measurement light" related to the technology of this disclosure. Of the Stokes lines and anti-Stokes lines, it is preferable to use Stokes lines as the Raman scattered light.

[0036] The Raman spectrometer 11 consists of a sensor unit 25 and an analyzer 26. The tip of the sensor unit 25 is connected to the flow cell 10. The sensor unit 25 emits excitation light EL from the outlet at its tip. The excitation light EL is irradiated onto the culture supernatant 15A flowing inside the flow cell 10. Raman scattered light is generated by the interaction between this excitation light EL and the antibodies 17 etc. in the culture supernatant 15A. The sensor unit 25 receives the Raman scattered light and outputs the received Raman scattered light to the analyzer 26. In this embodiment, laser light is used as the excitation light EL, with a laser output of 500mW, a center wavelength of 785nm, an irradiation time of 1 second, and a number of integrations of 10. The diameter of the laser beam is 3.50mm.

[0037] The analyzer 26 generates Raman spectral data 27 by decomposing the Raman scattered light into wavenumbers and deriving the intensity of the Raman scattered light for each wavenumber. The Raman spectral data 27 is an example of "physical property data" related to the technology of this disclosure. The analyzer 26 is connected to an information processing device (not shown) via a computer network such as a LAN (Local Area Network) so as to be able to communicate with it. The analyzer 26 transmits the generated Raman spectral data 27 to the information processing device. The information processing device is, for example, a personal computer. Based on the Raman spectral data 27 from the analyzer 26, the information processing device derives the concentration or composition ratio of antibodies 17, etc., in the culture supernatant 15A and displays the result on a display.

[0038] The Raman spectrum data 27 is data in which the intensity of Raman scattered light for each wavenumber is registered. In Figure 1, the Raman spectrum data 27 is data derived in 1 cm⁻¹ increments for scattered light in the range of wavenumbers from 500 cm⁻¹ to 3000 cm⁻¹. The graph G shown below the Raman spectrum data 27 plots the intensity of the Raman spectrum data 27 for each wavenumber and connects them with lines.

[0039] In this manner, the measurement system 2 flows the culture supernatant 15A obtained from the culture vessel 13 in which antibody-producing cells 16 are being cultured into the flow cell 10. Then, by irradiating the culture supernatant 15A flowing into the flow cell 10 with excitation light EL through the sensor unit 25, the system measures Raman spectral data 27 of antibodies 17 and other components in the culture supernatant 15A.

[0040] As an example, as shown in Figure 2, the flow cell 10 includes a main body 35 and a sensor connector 36. The main body 35 is a cylindrical member having a linear and circular cross-sectional flow path 37 in its central interior. The main body 35 is made of metal, such as Hastelloy. Alternatively, the main body 35 may be made of resin, such as polyolefin resin.

[0041] The main body 35 is provided with cylindrical boss-shaped first and second connection portions 38 and 39 at the center of both end faces. The first connection portion 38 has an inlet 40 for the flow path 37, and the second connection portion 39 has an outlet 41 for the flow path 37. The direction parallel to the flow path 37 from the inlet 40 to the outlet 41 is the flow direction FD of the culture supernatant 15A. Direction FD is an example of the "direction of fluid flow" related to the technology of this disclosure. As mentioned above, the flow path 37 has a circular cross-sectional shape, so the contour of the cross-sectional shape of the flow path 37 as seen from direction FD is curved (see also Figure 6). In other words, the flow path 37 as seen from direction FD has no corners.

[0042] The first connection part 38 and the second connection part 39 are parallel threads. A sterile connector 42, provided at one end of the first delivery passage 18, is liquid-tightly attached to the first connection part 38. Similarly, a sterile connector 43, provided at one end of the second delivery passage 19, is liquid-tightly attached to the second connection part 39. Note that the first connection part 38 and the second connection part 39 may also be tapered threads.

[0043] A mounting portion 44 is formed at the center of the circumferential surface of the main body 35. The mounting portion 44 is a hole for detachably attaching the sensor connector 36 to the main body 35, and threads 45 are cut into its inner circumferential surface. The mounting portion 44 extends to just before the flow path 37, and the tip of the sensor connector 36 is housed there. In the following description, the side on which the mounting portion 44 is formed will be referred to as the upper side of the main body 35.

[0044] The sensor connector 36 is a cylindrical member with a ball lens 46 at its tip. The outer circumferential surface of the tip of the sensor connector 36 has a thread 47 that engages with the thread 45 of the mounting portion 44. The tip of the sensor portion 25 is detachably connected to the base end of the sensor connector 36 opposite to the tip (see Figure 5). The sensor connector 36 is an example of a "connector" according to the technology of this disclosure.

[0045] The ball lens 46 is literally a spherical lens, and is made of, for example, quartz glass. The ball lens 46 collects the excitation light EL from the sensor unit 25 and also takes in the Raman scattered light generated by the interaction between the excitation light EL and the antibody 17 etc. in the culture supernatant 15A into the sensor unit 25. The ball lens 46 is an example of a "lens with positive refractive power" related to the technology of this disclosure.

[0046] As an example, as shown in Figure 3, the ball lens 46 is fitted and held in a first holding portion 55, which has a roughly U-shaped cross-section and is formed inside the tip of the sensor connector 36. The ball lens 46 is held in the first holding portion 55 with its excitation light EL emission surface 56 exposed to the outside from the tip of the sensor connector 36.

[0047] The main body 35 consists of an upper main body 35A and a lower main body 35B. The upper main body 35A and the lower main body 35B are formed by cutting the main body 35 in half right in the middle of the flow path 37. Therefore, the main body 35 is manufactured by integrating these upper main body 35A and lower main body 35B by bonding them together with an adhesive or the like.

[0048] In the upper body 35A, a transparent plate 59, an O-ring 60, and a plate retainer 61 are attached to the boundary portion 58 with the wall surface 57 that forms the lower channel 37 of the mounting portion 44 by four countersunk screws 62 (only three are shown in Figure 3). The transparent plate 59 is made of quartz glass with a transmittance of, for example, 95% or more of excitation light EL and Raman scattered light, and transmits excitation light EL from the ball lens 46 and Raman scattered light from substances in the culture supernatant 15A (see Figure 6). The transparent plate 59, together with the ball lens 46, constitutes the optical system 63 (see Figure 5, etc.). The boundary portion 58 is an example of "a part of the wall surface that forms the channel" according to the technology of this disclosure. The transparent plate 59 is an example of "an optical element" according to the technology of this disclosure.

[0049] The transparent plate 59 is fitted into and held in a second retaining portion 64, which is a circular recess connected to the lower side of the mounting portion 44. A stopper 65 is provided at the boundary between the mounting portion 44 and the second retaining portion 64, which abuts against the edge of the transparent plate 59 to prevent the transparent plate 59 from entering the mounting portion 44.

[0050] The plate holder 61 is fitted and held in place by a circular recess, the third holding portion 66, which is connected to the lower side of the second holding portion 64. The third holding portion 66 is provided with a screw hole 67 into which a countersunk screw 62 is screwed. Alternatively, the plate holder 61 may be fixed to the third holding portion 66 with adhesive instead of a countersunk screw 62.

[0051] The O-ring 60 is interposed between the transparent plate 59 and the plate retainer 61. The O-ring 60 is made of elastic rubber and is compressed between the transparent plate 59 and the plate retainer 61 when the plate retainer 61 is fastened and fixed to the third retaining part 66 by the countersunk screw 62 (see Figure 5, etc.). By being compressed between the transparent plate 59 and the plate retainer 61, the O-ring 60 prevents the culture supernatant 15A flowing through the channel 37 from leaking into the mounting part 44.

[0052] As an example, as shown in Figure 4, the transparent plate 59 is a circular disk in which the emission surface 70 of the excitation light EL and the incident surface 71 of the excitation light EL on the opposite side of the emission surface 70 are parallel. Here, "parallel" refers not only to perfect parallelism but also to parallelism that includes errors that are generally acceptable in the art to which the present disclosure belongs and that do not contradict the spirit of the present disclosure.

[0053] The O-ring 60 is a ring with a diameter slightly smaller than the diameter of the transparent plate 59. The plate retainer 61 is a thin, annular plate with an opening 72 in its center. The opening 72 has a diameter slightly smaller than the diameter of the O-ring 60. The opening 72 serves as the exit port for the excitation light EL and the entry port for the Raman scattered light. Through holes 73 for countersunk screws 62 are formed in the plate retainer 61 at 90° intervals.

[0054] Figures 5 and 6 show the state in which the transparent plate 59, O-ring 60, and plate retainer 61 are attached to the boundary portion 58 with countersunk screws 62, the upper body 35A and the lower body 35B are integrated, and the sensor connector 36 is attached to the mounting portion 44. In this state, the emission surface 56 of the ball lens 46 and the incident surface 71 of the transparent plate 59 are in contact with the optical axis OA (see Figure 6). The emission surface 70 of the transparent plate 59 is in contact with the culture supernatant 15A flowing through the channel 37. The emission surface 70 of the transparent plate 59 is an example of the "emission surface of measurement light in contact with a fluid" and "plane" in relation to the technology of this disclosure.

[0055] In Figure 6, the excitation light EL emitted from the exit surface 56 of the ball lens 46 is focused at the focusing position FP. The focusing position FP is determined by the diameter, refractive index, and focal length of the ball lens 46. In this case, the focusing position FP is point-like.

[0056] If Th is the thickness of the transparent plate 59 in the direction of the optical axis OA, and d is the distance between the first point P1 where the optical axis OA intersects on the exit surface 56 of the ball lens 46 and the focusing position FP, then the thickness Th is the same as the distance d, i.e., Th = d. In this case, the focusing position FP coincides with the second point P2 where the optical axis OA intersects on the exit surface 70 of the transparent plate 59. In other words, the focusing position FP is located on the exit surface 70 of the transparent plate 59. The thickness Th (and distance d) is between 0.3 mm and 7.5 mm (0.3 mm ≤ Th ≤ 7.5 mm). For example, the thickness Th (and distance d) is 2 mm. Note that "the same" thickness Th and distance d means not only being exactly the same (error 0), but also including errors that are generally acceptable in the art to which the present disclosure belongs and that do not contradict the spirit of the present disclosure. The error referred to here is preferably ±10%, more preferably ±5%.

[0057] The wall surface 57 forming the channel 37 is a smooth surface. A smooth surface is, for example, a surface without irregularities of 1 mm or more.

[0058] The diameter of the channel 37 is such that the Reynolds number Re in the channel 37 is 2300 or more (Re≧2300) under the conditions that the flow rate of the culture supernatant 15A flowing through the channel 37 is 200 cc / min or more, as shown in Figure 1, and the viscosity of the culture supernatant 15A is the same as water, 0.001 Pa·s. When the Reynolds number Re is 2300 or more, turbulence is generated in the culture supernatant 15A flowing through the channel 37. This reduces the bias of components in the culture supernatant 15A, thereby improving the measurement stability of the Raman spectrum data 27. The diameter of the channel 37 in the boundary portion 58 where the transparent plate 59 is provided is the distance between the second point P2 where the optical axis OA intersects on the exit surface 70 of the transparent plate 59 and the point where the optical axis OA intersects on the wall surface 57.

[0059] Next, the operation of the above configuration will be explained. The measurement system 2, consisting of a flow cell 10 and a Raman spectrometer 11, is incorporated into the cell culture section 12. The flow cell 10 has a first connection section 38 connected to the first discharge channel 18 and a second connection section 39 connected to the second discharge channel 19, and the sensor section 25 of the Raman spectrometer 11 is connected to the sensor section connector 36. Culture supernatant 15A obtained from a culture tank 13 in which antibody-producing cells 16 are cultured flows through the flow channel 37 of the flow cell 10. The culture supernatant 15A flowing through the flow channel 37 is irradiated with excitation light EL via the sensor section 25 and the optical system 63. The excitation light EL is focused at a focusing position FP on the output surface 70 of the transparent plate 59.

[0060] Raman scattered light is generated by the interaction between the excitation light EL and the antibody 17 in the culture supernatant 15A. The Raman scattered light is captured by the sensor unit 25 by the optical system 63 and output from the sensor unit 25 to the analyzer 26. The Raman scattered light is converted into Raman spectral data 27 by the analyzer 26.

[0061] The transparent plate 59 constituting the optical system 63 has its excitation light EL emission surface 70 in contact with the culture supernatant 15A flowing through the channel 37. The emission surface 70 is planar. Compared to the case described in Japanese Patent Publication No. 2020-511635, in which the emission surface 56 of a ball lens 46 with positive refractive power is in contact with the culture supernatant 15A, the distance d from the excitation light EL emission surface 70 to the focusing position FP can be shortened (set to 0 in this example). Therefore, the risk of the excitation light EL being attenuated by the culture supernatant 15A can be reduced. Consequently, the risk of not being able to obtain sufficient light intensity of the excitation light EL to obtain analysis-worthy Raman spectral data 27 can be reduced. As a result, the signal-to-noise ratio of the Raman spectral data 27 generated by Raman scattering light due to the interaction between the excitation light EL and the antibody 17 etc. in the culture supernatant 15A can be maintained at a high level.

[0062] The optical system 63 includes a ball lens 46 with positive refractive power and a transparent plate 59 whose emission surface 70 for the excitation light EL, which is in contact with the culture supernatant 15A, is flat. Therefore, focusing of the excitation light EL and reduction of the attenuation of the excitation light EL can be achieved with a simple configuration.

[0063] The ball lens 46 has relatively high refractive power, which allows the distance d between the first point P1 where it intersects the optical axis OA on the emission surface 56 and the focusing position FP to be shortened. As a result, the thickness Th of the transparent plate 59 in the direction of the optical axis OA can be made thinner, which in turn contributes to miniaturization of the flow cell 10.

[0064] As shown in Figure 4, the transparent plate 59 is a circular disc in which the emission surface 70 of the excitation light EL that is in contact with the culture supernatant 15A and the incidence surface 71 of the excitation light EL on the opposite side of the emission surface 70 are parallel. Therefore, the transparent plate 59 can be easily manufactured.

[0065] As shown in Figure 6, the thickness Th of the transparent plate 59 in the direction of the optical axis OA is the same as the distance d between the first point P1 where the optical axis OA intersects at the exit surface 56 of the ball lens 46 and the focusing position FP, and the focusing position FP is located at the exit surface 70 of the transparent plate 59. Therefore, the risk of the excitation light EL being attenuated by the culture supernatant 15A can be reduced to the absolute minimum, and the amount of excitation light EL required to obtain Raman spectral data 27 that is suitable for analysis can be greatly increased.

[0066] Furthermore, as shown in Figure 6, the thickness Th of the transparent plate 59 in the optical axis direction OA is between 0.3 mm and 7.5 mm. If the thickness Th is 0.3 mm or more, it can reduce the risk of the excitation light EL being attenuated by the culture supernatant 15 A. If the thickness Th is 7.5 mm or less, it can contribute to miniaturization of the flow cell 10 and provide good handling.

[0067] As shown in Figure 2, the flow cell 10 is equipped with a sensor connector 36 to which the sensor unit 25 of the Raman spectrometer 11, which outputs Raman spectral data 27, is connected. A ball lens 46 is positioned at the tip of the sensor connector 36. The sensor connector 36 is detachable from the main body 35. Therefore, the sensor connector 36 can be reused in multiple flow cells 10. Since it is not necessary to provide a sensor connector 36 in every flow cell 10, this contributes to reducing the cost of the flow cells 10.

[0068] As shown in Figure 6, the wall surface 57 forming the channel 37 is a smooth surface. Therefore, the risk of bubbles that obstruct the flow of the culture supernatant 15A can be reduced. The stability of the flow of the culture supernatant 15A can be ensured.

[0069] As shown in Figure 1, the turbidity of the culture supernatant 15A is between 250 NTU and 1000 NTU. In this case, the attenuation of the excitation light EL by the culture supernatant 15A becomes greater, so the effect of making the emission surface 70 of the excitation light EL in contact with the culture supernatant 15A a flat surface can be further demonstrated.

[0070] Raman scattering light readily reflects information derived from the functional groups of amino acids in proteins. Therefore, by using Raman spectral data 27 as physical property data, as in this example, physical property values ​​such as the concentration of the antibody 17 (a protein) can be derived with high accuracy.

[0071] Biopharmaceuticals containing antibody 17, which is a cell product, are called antibody drugs and are widely used to treat chronic diseases such as cancer, diabetes, and rheumatoid arthritis, as well as rare diseases such as hemophilia and Crohn's disease. Therefore, in this example, using the culture supernatant 15A obtained from the culture vessel 13 during the cultivation of antibody-producing cells 16 as the fluid, it is possible to accelerate the development of antibody drugs that are widely used to treat various diseases.

[0072] In this example, the culture supernatant 15A obtained from the culture vessel 13 during cultivation is used as the fluid. Therefore, Raman spectral data 27 can be measured while continuing to culture antibody-producing cells 16 in the culture vessel 13.

[0073] In this example, the transparent plate 59 is placed at the boundary portion 58 between the wall surface 57 forming the flow path 37 and the mounting portion 44, but this is not limited to this. The second holding portion 64 that holds the transparent plate 59 and the third holding portion 66 that holds the plate retainer 61 may be extended beyond the boundary portion 58 to the central part of the flow path 37, and the transparent plate 59, etc., may be positioned so that the ejection surface 70 is in the central part of the flow path 37.

[0074] (Variation 1) As an example, as shown in Figure 7, the exit surface 56 of the ball lens 46 and the incident surface 71 of the transparent plate 59 do not have to be in contact. Also, the focusing position FP does not have to coincide with the second point P2 where it intersects the optical axis OA on the exit surface 70 of the transparent plate 59. In other words, the focusing position FP does not have to be located on the exit surface 70 of the transparent plate 59.

[0075] However, in this case, the thickness Th of the transparent plate 59 in the direction of the optical axis OA is more than half the distance d between the first point P1 where the optical axis OA intersects at the exit surface 56 of the ball lens 46 and the focusing position FP, and less than or equal to the distance d (d / 2 ≤ Th ≤ d). If the thickness Th is more than half the distance d, it can reduce the risk of the excitation light EL being attenuated by the culture supernatant 15A. If the thickness Th is less than or equal to the distance d, the focusing position FP can always be outside the transparent plate 59 (inside the flow path 37).

[0076] (Modification 2) As an example, the optical system 80 of Modification 2 shown in Figure 8 includes a ball lens 46 and an optical element 81. The optical element 81 has an emission surface 82 for excitation light EL that is in contact with the planar culture supernatant 15A, and an incidence surface 83 that conforms to the shape of the emission surface 56 of the ball lens 46. The curvature of the emission surface 56 of the ball lens 46 and the incidence surface 83 of the optical element 81 are the same, and the emission surface 56 and the incidence surface 83 are joined. Here, "joined" means that the emission surface 56 and the incidence surface 83 may be fixedly joined together with an adhesive or the like, or they may simply be held together with their surfaces facing each other without the use of an adhesive or the like.

[0077] The thickness Th of the optical element 81 in the direction of the optical axis OA is the distance between a second point P2 where the optical axis OA intersects the exit surface 82 of the optical element 81 and a third point P3 where the optical axis OA intersects the incident surface 83 of the optical element 81.

[0078] Since the curvature of the exit surface 56 and the incident surface 83 are the same, no gap is created between the joined exit surface 56 and the incident surface 83. Therefore, the attenuation of the excitation light EL and Raman scattered light due to the gap between the exit surface 56 and the incident surface 83 can be suppressed.

[0079] Here, "identical" curvature refers not only to complete identicalness but also to identicalness that includes errors generally accepted in the art to which the disclosed technology belongs, and that do not contradict the spirit of the disclosed technology. More specifically, "identical" curvature here means that the difference in curvature between the exit surface 56 and the incident surface 83 is within 10%. Expressed as an equation, if m is the smaller absolute value of the curvature of the exit surface 56 and the curvature of the incident surface 83, and n is the larger absolute value, then 0.9 × |n| ≤ |m|. This definition of "identical" curvature also applies to Figures 9 to 12 thereafter. Preferably, "identical" curvature means that the difference in curvature between the exit surface 56 and the incident surface 83 is within 8%, more preferably within 5%, and even more preferably within 3%. Curvature can be measured using equipment such as the ultra-high precision three-dimensional measuring instrument UA3P manufactured by Panasonic Production Engineering Co., Ltd. For the emission surface 56, the curvature can be derived from the number of Newtonian rings that appear when the Newtonian prototype and the emission surface 56 are superimposed.

[0080] Thus, the optical element is not limited to a disc-shaped transparent plate 59 having an exit surface 70 and an incident surface 71 that are parallel to each other, but may also be an optical element 81 having a planar exit surface 82 and an incident surface 83 whose shape follows that of the exit surface 56 of the ball lens 46. Furthermore, the lens to be combined with such an optical element 81, which has a planar exit surface and an incident surface whose shape follows that of the exit surface of the lens, is not limited to the illustrated ball lens 46, but may also be a plano-convex lens, a biconvex lens, or the like.

[0081] (Variation 3) As an example, the optical system 85 of Modification 3 shown in Figure 9 includes a hemispherical lens 86 and a transparent plate 87. The hemispherical lens 86 is literally a hemispherical lens and is made of, for example, quartz glass. The hemispherical lens 86 has an emission surface 88 for excitation light EL. The emission surface 88 is flat. The hemispherical lens 86 is an example of a "lens with positive refractive power" related to the technology of this disclosure.

[0082] The transparent plate 87, like the transparent plate 59, is a disc having a mutually parallel emission surface 89 and incidence surface 90 for excitation light EL. The transparent plate 87 is an example of an "optical element" according to the technology of this disclosure. The curvature of the emission surface 88 of the hemispherical lens 86 and the incidence surface 90 of the transparent plate 87 are the same (0 in this case), and the emission surface 88 and incidence surface 90 are joined together. With the hemispherical lens 86, since the emission surface 88 is planar, the curvature of the incidence surface 90 of the transparent plate 87 can be easily made the same as the curvature of the emission surface 88, compared to the case in Figure 8. In the following examples as well, when the emission surface of the lens and the incidence surface of the transparent plate are planar, the curvature is assumed to be 0.

[0083] (Modification 4) As an example, the optical system 95 of Modification 4 shown in Figure 10 includes a plano-convex lens 96 and a transparent plate 97. The plano-convex lens 96 is a lens in which the incident surface 98 for the excitation light EL is a spherical convex surface and the exit surface 99 for the excitation light EL is a flat surface, and is made of, for example, quartz glass. The plano-convex lens 96 is an example of a "lens with positive refractive power" related to the technology of this disclosure.

[0084] The transparent plate 97, like the transparent plate 59, is a disc having a mutually parallel emission surface 100 and an incidence surface 101 for excitation light EL. The transparent plate 97 is an example of an "optical element" according to the technology of this disclosure. The curvature of the emission surface 99 of the plano-convex lens 96 and the incidence surface 101 of the transparent plate 97 are the same (0 in this case), and the emission surface 99 and the incidence surface 101 are joined together. With the plano-convex lens 96, as with the hemispherical lens 86, the curvature of the incidence surface 101 of the transparent plate 97 can be easily made the same as the curvature of the emission surface 99 compared to the case in Figure 8. Furthermore, since the plano-convex lens 96 is less expensive than the ball lens 46 and the hemispherical lens 86, it can contribute to reducing the cost of the flow cell 10.

[0085] (Variation 5) As an example, the optical system 105 of Modification 5 shown in Figure 11 includes a plano-convex lens 106 and a transparent plate 107. The plano-convex lens 106 is a lens in which the incident surface 108 for the excitation light EL is an aspherical convex surface and the exit surface 109 for the excitation light EL is a plane, and is made of, for example, quartz glass or resin. The plano-convex lens 106 is an example of a "lens with positive refractive power" related to the technology of this disclosure.

[0086] The transparent plate 107, like the transparent plate 59, is a disc having an emission surface 110 and an incidence surface 111 for excitation light EL that are parallel to each other. The transparent plate 107 is an example of an "optical element" according to the technology of this disclosure. The curvature of the emission surface 109 of the plano-convex lens 106 and the incidence surface 111 of the transparent plate 107 are the same (0 in this case), and the emission surface 109 and the incidence surface 111 are joined together. With the plano-convex lens 106, as with the hemispherical lens 86, the curvature of the incidence surface 111 of the transparent plate 107 can be easily made the same as the curvature of the emission surface 109, compared to the case in Figure 8. In addition, since the incidence surface 108 of the plano-convex lens 106 is aspherical, spherical aberration can be suppressed compared to the plano-convex lens 96 which has a spherical incidence surface 98.

[0087] (Experimental variation 6) As an example, the optical system 115 of modified example 6 shown in Figure 12 includes a cylindrical lens 116 and a transparent plate 117. The cylindrical lens 116 is a lens with a crescent-shaped cross-section obtained by vertically slicing a cylinder, and is made of, for example, quartz glass. The cylindrical lens 116 has an incident surface 118 for excitation light EL, which is a spherical convex surface, and an exit surface 119 for excitation light EL. The exit surface 119 is a rectangular plane. The cylindrical lens 116 is an example of a "lens with positive refractive power" related to the technology of this disclosure. Note that the incident surface 118 of the cylindrical lens 116 may be aspherical.

[0088] The transparent plate 117 is a rectangular plate having an emission surface 120 and an incidence surface 121 for excitation light EL that are parallel to each other. The transparent plate 117 is an example of an "optical element" according to the technology of this disclosure. The curvature of the emission surface 119 of the cylindrical lens 116 and the incidence surface 121 of the transparent plate 117 are the same (0 in this case), and the emission surface 119 and the incidence surface 121 are joined together. With the cylindrical lens 116, as with the hemispherical lens 86, etc., the curvature of the incidence surface 121 of the transparent plate 117 can be easily made the same as the curvature of the emission surface 119, compared to the case in Figure 8.

[0089] The ball lens 46, hemispherical lens 86, and plano-convex lenses 96 and 106 focus the excitation light EL in a point-like manner, while the cylindrical lens 116 focuses the excitation light EL linearly, as shown in Figures 13 and 14 as an example. Figure 13 shows the case where the excitation light EL is focused linearly parallel to the direction FD. On the other hand, Figure 14 shows the case where the excitation light EL is focused linearly perpendicular to the direction FD.

[0090] As shown in Figure 13, when excitation light EL is focused linearly parallel to the direction FD, the temporal changes in the culture supernatant 15A flowing through the channel 37 can be reflected in the Raman spectral data 27. On the other hand, as shown in Figure 14, when excitation light EL is focused linearly perpendicular to the direction FD, the spatial changes in the culture supernatant 15A flowing through the channel 37 can be reflected in the Raman spectral data 27. In either case, the measurement stability of the Raman spectral data 27 can be improved compared to when excitation light EL is focused in a point-like manner.

[0091] In modifications 2 to 6, the curvature of the exit surface of the lens and the incident surface of the optical element are the same, and the exit surface of the lens and the incident surface of the optical element are joined, but the invention is not limited to these. The invention also includes embodiments in which the curvature of the exit surface of the lens and the incident surface of the optical element are the same, but the exit surface of the lens and the incident surface of the optical element are not joined. In this invention, "not joined" is synonymous with "not in contact" in the explanation given in Modification 1 shown in Figure 7, where "the exit surface 56 of the ball lens 46 and the incident surface 71 of the transparent plate 59 do not have to be in contact."

[0092] [Second Embodiment] In the first embodiment described above, an optical system combining a lens and an optical element, such as an optical system 63 including a ball lens 46 and a transparent plate 59, was exemplified, but the invention is not limited thereto. As an example, as shown in Figure 15, the optical system may be configured with only a hemispherical lens 86. In this case, the emission surface 88 of the excitation light EL of the hemispherical lens 86 will be in contact with the culture supernatant 15A flowing through the channel 37. The emission surface 88 is an example of the "emission surface of measurement light in contact with a fluid" and "plane" related to the technology of this disclosure.

[0093] Furthermore, as an example, the optical system may be constructed using only the cylindrical lens 116, as shown in Figures 16 and 17. In this case, the emission surface 119 of the excitation light EL of the cylindrical lens 116 will be in contact with the culture supernatant 15A flowing through the channel 37. The emission surface 119 is an example of the "emission surface of measurement light in contact with a fluid" and "plane" related to the technology of this disclosure. Figure 16 shows the case in which the excitation light EL is focused in a linear direction parallel to the direction FD, similar to the case in Figure 13. On the other hand, Figure 17 shows the case in which the excitation light EL is focused in a linear direction perpendicular to the direction FD, similar to the case in Figure 14.

[0094] Thus, in the second embodiment, the optical system includes a lens that has positive refractive power and whose emission surface for the excitation light EL that contacts the culture supernatant 15A is planar. Therefore, the configuration of the optical system can be simplified compared to the optical system combining the lens and optical elements of the first embodiment. Note that, as shown in Figure 18, the optical system may be constructed using only the plano-convex lens 96 shown in Figure 10. Alternatively, as shown in Figure 19, the optical system may be constructed using only the plano-convex lens 106 shown in Figure 11.

[0095] Instead of constructing an optical system with separate lenses and optical elements each having positive refractive power, the optical system 125 may be formed by integrally combining the hemispherical lens 86 and transparent plate 87 shown in Figure 9, as shown in Figure 20, as a single lens.

[0096] [Examples] Examples of the technology described herein and comparative examples are described below.

[0097] In this example, a phenylalanine solution was used as the fluid for measuring the Raman spectral data 27. The phenylalanine solution was prepared by dissolving L(-)-phenylalanine, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., in water as the solvent to a concentration of 10 g / L. Then, a powdered culture medium was added to the prepared phenylalanine solution to change the turbidity. Phenylalanine was chosen because it is one of the representative amino acids contained in cell culture media, and its peak in the Raman spectral data 27 is relatively easy to distinguish. As the powdered culture medium, for example, CD OptiCHOTM AGT™ Medium manufactured by Thermo Fisher Scientific can be used. Turbidity was measured using a digital turbidimeter TU-2016 manufactured by Satotec.

[0098] The lenses used were hemispherical lenses 86 (Examples 1-7) or ball lenses 46 (Examples 8-10, Comparative Examples 1-3). The hemispherical lenses 86 and ball lenses 46 had a diameter of 8 mm and were made of quartz glass (S-BSL).

[0099] The prepared phenylalanine solution was injected into channel 37 using a syringe. The phenylalanine solution injected into channel 37 was irradiated with excitation light (EL) from the Raman spectrometer 11. A laser beam was used as the excitation light (EL), with a laser output of 500 mW, a center wavelength of 785 nm, an irradiation time of 1 second, and 10 integration cycles. The obtained raw Raman spectrum data 27 was then subjected to baseline correction, and the difference between this data and the Raman spectrum data 27 of water (the solvent), which had also undergone baseline correction, was used as the final Raman spectrum data 27 for evaluating the signal-to-noise ratio.

[0100] In Raman spectral data 27, the maximum intensity among the wavenumbers 1000 cm⁻¹ to 10¹¹ cm⁻¹ attributed to phenylalanine was used as the signal value for calculating the signal-to-noise ratio (S / N ratio). In addition, in Raman spectral data 27, the standard deviation of the intensities at wavenumbers 695 cm⁻¹ to 721 cm⁻¹, which are not derived from phenylalanine or other amino acids, was used as the noise value for calculating the S / N ratio.

[0101] Each example was evaluated by varying the turbidity and the thickness Th in the optical axis OA direction of the optical element (transparent plate). In addition to the signal-to-noise ratio mentioned above, the stability of the fluid flow and robustness to turbidity changes were also evaluated. Table 130, which summarizes the conditions and evaluation items for the examples and comparative examples, is shown in Figure 21. The evaluation is as follows: "A" is excellent, "B" is good, "C" is acceptable, and "D" is unacceptable.

[0102] Example 1 is an example in which the turbidity of the phenylalanine solution is 243 NTU, the lens is a hemispherical lens 86, the distance d is 3.5 mm, the curvature of the emission surface 88 is 0, and there is no optical element (transparent plate 87). That is, Example 1 is the configuration shown in Figure 15. The signal-to-noise ratio in Example 1 was 62.3, which is "A". The reason the signal-to-noise ratio was "A" is that the emission surface 88 of the excitation light EL of the hemispherical lens 86 in contact with the phenylalanine solution is flat.

[0103] Example 2 is an example in which a transparent plate 87 with a thickness Th of 2 mm and a curvature of 0 on the incident surface 90 is bonded to the exit surface 88 of the hemispherical lens 86, as in Example 1. In Example 2, the curvature of the exit surface 88 of the hemispherical lens 86 and the incident surface 90 of the transparent plate 87 are the same. That is, Example 2 is the configuration shown in Figure 9. Furthermore, in Example 2, the thickness Th is smaller than the distance d, and the distance d and thickness Th are inconsistent. The signal-to-noise ratio in Example 2 was 45.6, which was "B". The reason why the signal-to-noise ratio was "B" and worse than in Example 1 is due to the mismatch between the distance d and thickness Th.

[0104] Example 3 is an example in which a transparent plate 87 with a thickness Th of 3.5 mm and a curvature of 0 on the incident surface 90 is bonded to the exit surface 88 of the hemispherical lens 86, as in Example 1. In Example 3, as in Example 2, the curvature of the exit surface 88 of the hemispherical lens 86 and the incident surface 90 of the transparent plate 87 are the same. That is, Example 3 is the same configuration as shown in Figure 9. However, in Example 3, the distance d and the thickness Th are the same. The signal-to-noise ratio in Example 3 was 65.7, which was "A". The improvement in the signal-to-noise ratio to "A" compared to Example 2 is due to the provision of a transparent plate 87 with a distance d and thickness Th that are the same.

[0105] Example 4 was the same as Example 1, except that the turbidity of the phenylalanine solution was set to 370 NTU. The signal-to-noise ratio (S / N ratio) in Example 4 was 56.2, which was "B". The reason the S / N ratio worsened to "B" compared to Example 1 was due to the increased turbidity of the phenylalanine solution.

[0106] Example 5 is the same as Example 3, except that the turbidity of the phenylalanine solution was set to 370 NTU. The signal-to-noise ratio in Example 5 was 66.4, which was "A". The improvement in the signal-to-noise ratio to "A" compared to Example 4 was due to the provision of a transparent plate 87 in which the distance d and thickness Th were equal.

[0107] Example 6 is the same as Examples 1 and 4, except that the turbidity of the phenylalanine solution was set to 441 NTU. The signal-to-noise ratio (S / N ratio) in Example 6 was 38.6, which was "C". The S / N ratio worsened to "C" compared to Examples 1 and 4 because the turbidity of the phenylalanine solution increased.

[0108] Example 7 is the same as Examples 3 and 5, except that the turbidity of the phenylalanine solution was set to 441 NTU. The signal-to-noise ratio in Example 7 was 62.1, which was "A". The improvement in the signal-to-noise ratio to "A" compared to Example 6 was due to the provision of a transparent plate 87 in which the distance d and thickness Th were equal.

[0109] In Examples 1-7, which used only the hemispherical lens 86 or the hemispherical lens 86 and the transparent plate 87, the flow stability was rated "B" and the robustness to turbidity changes was rated "C".

[0110] Example 8 is an example in which a phenylalanine solution has a turbidity of 441 NTU, a ball lens 46 is used, the distance d is 2 mm, the curvature of the exit surface 56 is 0.25, and a transparent plate 59 with a thickness Th of 1 mm and an incident surface 71 curvature of 0 is provided. Example 8 is an example in which the thickness Th is smaller than the distance d, and the distance d and thickness Th do not match. Also, Example 8 is an example in which the curvature of the exit surface 56 of the ball lens 46 and the incident surface 71 of the transparent plate 59 are different. The S / N ratio in Example 8 was 31.4, which was "C". The reason the S / N ratio was "C" is that the distance d and thickness Th do not match, and the curvature of the exit surface 56 of the ball lens 46 and the incident surface 71 of the transparent plate 59 are different.

[0111] Example 9 is an example in which, instead of the transparent plate 59 with a thickness Th of 1 mm and a curvature of 0 on the incident surface 71 of Example 8, an optical element 81 with a thickness Th of 1 mm and a curvature of 0.25 on the incident surface 83 is bonded to the exit surface 56 of the ball lens 46. In other words, Example 9 is the embodiment shown in Figure 8. In Example 9, the thickness Th is smaller than the distance d, and the distance d and thickness Th are mismatched, just like in Example 8, but it differs from Example 8 in that the curvature of the exit surface 56 of the ball lens 46 and the incident surface 83 of the optical element 81 are the same. The signal-to-noise ratio in Example 9 was 52.3, which was "B". The improvement in the signal-to-noise ratio to "B" compared to Example 8 is due to the fact that the curvature of the exit surface 56 of the ball lens 46 and the incident surface 83 of the optical element 81 are the same.

[0112] Example 10 is an example in which an optical element 81 with a thickness Th of 2 mm and a curvature of 0.25 on its incident surface 83 is bonded to the exit surface 56 of a ball lens 46. Like Example 9, Example 10 is an example in which the curvature of the exit surface 56 of the ball lens 46 and the incident surface 83 of the optical element 81 are the same. That is, Example 10 is the same configuration as shown in Figure 8. However, in Example 10, the distance d and the thickness Th are the same. The signal-to-noise ratio in Example 10 was 61.8, which was "A". The improvement in the signal-to-noise ratio to "A" compared to Example 9 is due to the provision of an optical element 81 in which the distance d and thickness Th are the same.

[0113] In Examples 8-10, which used a ball lens 46 and a transparent plate 59 or 81, the flow stability was "B" and the robustness to turbidity changes was "B". The improvement in robustness to turbidity changes to "B" compared to Examples 1-7, which used a hemispherical lens 86, is due to the use of a ball lens 46 with a shorter distance d than that of a hemispherical lens 86.

[0114] Comparative Example 1 is an example in which the turbidity of the phenylalanine solution is 243 NTU, the lens is a ball lens 46, the distance d is 2 mm, the curvature of the exit surface 56 is 0.25, and there is no optical element (transparent plate 59 or 81). In other words, Comparative Example 1 is the embodiment described in Japanese Patent Publication No. 2020-511635. The signal-to-noise ratio in Comparative Example 1 was 51.2, which was "B".

[0115] Comparative Example 2 was the same as Comparative Example 1, except that the turbidity of the phenylalanine solution was set to 370 NTU. The signal-to-noise ratio (S / N ratio) in Comparative Example 2 was 39.4, which was "C". The reason the S / N ratio worsened to "C" compared to Comparative Example 1 was due to the increased turbidity of the phenylalanine solution.

[0116] Comparative Example 3 is the same as Comparative Example 1, except that the turbidity of the phenylalanine solution was set to 441 NTU. The signal-to-noise ratio (S / N ratio) in Comparative Example 3 was 46.9, which was "B". The reason why the S / N ratio improved to "B" compared to Comparative Example 2 is unknown.

[0117] In comparative examples 1 to 3, which used only the ball lens 46, the flow stability was "D" and the robustness to turbidity changes was "B". The reason for the flow stability being "D" is that the surface in contact with the flow path 37 is the exit surface 56 of the ball lens 46, which is not flat.

[0118] The signal-to-noise ratios (S / N ratios) in Examples 1 to 10, to which the technology of this disclosure is applied, all fall within the range of "A" to "C". Therefore, the effectiveness of the technology of this disclosure has been confirmed in that it is possible to reduce the risk of not being able to obtain sufficient excitation light EL to obtain Raman spectral data 27 that is suitable for analysis.

[0119] In Examples 1-3 and Comparative Example 1, which all share a turbidity of 243 NTU for the phenylalanine solution, the signal-to-noise ratio (S / N ratio) of Examples 1 and 3 is higher than that of Comparative Example 1. Similarly, in Examples 4 and 5 and Comparative Example 2, which all share a turbidity of 370 NTU for the phenylalanine solution, the S / N ratio of Examples 4 and 5 is higher than that of Comparative Example 2. Furthermore, in Examples 6-10 and Comparative Example 3, which all share a turbidity of 441 NTU for the phenylalanine solution, the S / N ratio of Examples 7, 9, and 10 is higher than that of Comparative Example 3. Therefore, it was confirmed that it is possible to increase the amount of excitation light EL required to obtain Raman spectral data 27 suitable for analysis compared to conventional methods.

[0120] The lenses are not limited to the exemplified ball lens 46, hemispherical lens 86, plano-convex lenses 96 and 106, or cylindrical lens 116. They may be biconvex lenses with convex incident and exit surfaces for the excitation light EL, or fly-eye lenses in which multiple lenses are arranged in a two-dimensional matrix.

[0121] The sensor connector 36 may be permanently attached to the main body 35. The first connection part 38 and the second connection part 39 may be positioned on the underside of the main body 35, and the flow path 37 may be U-shaped. The shape of the main body 35 is not limited to cylindrical; it may also be rectangular. The cross-sectional shape of the flow path 37 is not limited to circular; it may also be elliptical or rectangular. Furthermore, the main body 35 may be formed from a composite material such as polyolefin resin or carbon fiber reinforced resin.

[0122] The substances to be measured for Raman spectral data 27 are not limited to antibodies 17, etc. Other substances such as proteins, peptides, nucleic acids (DNA, RNA (Ribonucleic Acid)), lipids, viruses, viral subunits, and virus-like particles may also be measured.

[0123] Cell products are not limited to antibody 17, etc. They may also include cytokines (interferon, interleukin, etc.), hormones (insulin, glucagon, follicle-stimulating hormone, erythropoietin, etc.), growth factors (IGF (Insulin-Like Growth Factor)-1, bFGF (Basic Fibroblast Growth Factor), etc.), blood coagulation factors (factor VII, factor VIII, factor IX, etc.), enzymes (lysosomal enzymes, DNA (deoxyribonucleic acid) degrading enzymes, etc.), Fc (Fragment Crystallizable) fusion proteins, receptors, albumin, and protein vaccines. Furthermore, antibody 17 also includes bispecific antibodies, antibody-drug conjugates, small molecule antibodies, and glycosylated antibodies.

[0124] Physical property data is not limited to Raman spectral data 27. Infrared absorption spectral data, nuclear magnetic resonance spectral data, ultraviolet-visible (UV-Vis) spectral data, or fluorescence spectral data are also acceptable. For this reason, the optical analyzer is not limited to a Raman spectrometer 11.

[0125] The fluid is not limited to the culture supernatant 15A. It may also be the cell culture medium 15 before cell removal by the cell removal filter 14. It may also be the cell culture medium (so-called culture medium) that does not contain cell products before being supplied to the culture tank 13. It may also be the purified solution obtained by purifying the culture supernatant 15A using a chromatography apparatus in the purification unit. The fluid is not limited to the cell culture medium 15; for example, it may be river water collected to investigate water pollution. It may also be the raw materials (for example, an aqueous solution of polystyrene lithium and methanol, etc.) and / or products used in the continuous production of monomers or polymers (for example, polystyrene, etc.) by flow synthesis. Furthermore, the fluid is not limited to a liquid but may also be a gas.

[0126] From the above description, the technology described in the following supplementary information can be understood.

[0127] [Additional note 1] A main body having a channel through which a fluid containing the substance to be measured for physical property data flows, An optical system disposed in a part of the wall surface forming the flow channel and for collecting the measurement light for the physical property data, wherein the optical system has a flat surface on which the measurement light is emitted and in contact with the fluid, Equipped with, Flow cell. [Additional note 2] The flow cell according to Appendix 1, wherein the optical system includes a lens having a positive refractive power and an optical element whose surface for emitting the measurement light in contact with the fluid is planar. [Additional note 3] The flow cell according to Appendix 2, wherein the lens is one of a ball lens, a hemispherical lens, or a cylindrical lens. [Additional note 4] If the lens is the cylindrical lens, The cylindrical lens is a flow cell according to Appendix 3, which focuses the measurement light in a linear manner parallel or perpendicular to the direction of fluid flow. [Additional note 5] The flow cell according to any one of Appendix 2 to Appendix 4, wherein the optical element is a transparent plate in which the emission surface of the measurement light in contact with the fluid and the incident surface of the measurement light on the opposite side of the emission surface of the measurement light in contact with the fluid are parallel. [Additional note 6] The flow cell according to any one of Appendix 2 to Appendix 5, wherein the thickness of the optical element in the direction of the optical axis is less than or equal to the distance between the point where the optical axis intersects the exit surface of the lens and the focusing position of the measurement light. [Additional note 7] The flow cell according to Appendix 6, wherein the thickness is more than half of the distance. [Additional note 8] The aforementioned thickness is the same as the aforementioned distance, The light-collecting position is located on the emission surface of the optical element in the flow cell as described in Appendix 6 or Appendix 7. [Additional note 9] The flow cell described in any one of the appendix items 6 to 8, wherein the thickness is 0.3 mm or more and 7.5 mm or less. [Additional Note 10] A flow cell according to any one of the appendices 2 to 9, wherein the curvature of the exit surface of the lens and the incident surface of the optical element are the same. [Additional Note 11] The flow cell described in Appendix 10, wherein the exit surface of the lens and the incident surface of the optical element are joined together. [Additional Note 12] A flow cell according to any one of Appendix 2 to Appendix 11, to which an optical analyzer that outputs the aforementioned physical property data is connected, wherein the connector, having the lens disposed at its tip, is detachably provided on the main body. [Additional Note 13] The flow cell according to Appendix 1, wherein the optical system includes a lens having a positive refractive power and the emission surface of the measurement light in contact with the fluid is flat. [Additional Note 14] The flow cell according to Appendix 13, wherein the lens is either a hemispherical lens or a cylindrical lens. [Additional Note 15] If the lens is the cylindrical lens, The cylindrical lens is a flow cell according to Appendix 14, which focuses the measurement light in a linear manner parallel or perpendicular to the direction of fluid flow. [Additional Note 16] The flow cell according to any one of the appendix items 1 to 15, wherein the wall surface is a smooth surface. [Additional Note 17] The flow cell described in any one of the appendix 1 to 16, wherein the turbidity of the fluid is 250 NTU or more and 1000 NTU or less. [Additional Note 18] The aforementioned physical property data is Raman spectral data, as specified in any one of the appendices 1 to 17 of the flow cell. [Additional Note 19] A measurement method for measuring the physical property data using a flow cell described in any one of the appendices 1 to 18. [Additional Note 20] The measurement method described in Appendix 19, wherein the fluid is a cell culture medium. [Additional Note 21] The measurement method according to Appendix 20, wherein the cell culture medium includes cell products as the substance. [Additional Note 22] The measurement method according to Appendix 20 or Appendix 21, wherein the cell culture medium is obtained from a culture vessel during cultivation. [Additional Note 23] The measurement method according to any one of Appendix 20 to Appendix 22, wherein the cell culture medium is one from which cells have been removed.

[0128] The technology disclosed herein can be appropriately combined with the various embodiments and / or variations described above. Furthermore, it is understood that various configurations can be adopted without departing from the spirit of the invention, and are not limited to the embodiments described above.

[0129] The descriptions and illustrations presented above are detailed explanations of the technical aspects of this disclosure and are merely examples of the technical aspects. For example, the above descriptions of the structure, function, operation, and effect are examples of the structure, function, operation, and effect of the technical aspects of this disclosure. Therefore, it goes without saying that you may delete unnecessary parts, add new elements, or replace elements in the descriptions and illustrations presented above, as long as you do not deviate from the essence of the technical aspects of this disclosure. Furthermore, in order to avoid confusion and facilitate understanding of the technical aspects of this disclosure, explanations of common technical knowledge and the like that do not require special explanation to enable the implementation of the technical aspects of this disclosure have been omitted from the descriptions and illustrations presented above.

[0130] In this specification, "A and / or B" is synonymous with "at least one of A and B." That is, "A and / or B" means that it may be A alone, or B alone, or a combination of A and B. Furthermore, in this specification, the same concept as "A and / or B" applies when expressing three or more things linked by "and / or."

[0131] All documents, patent applications, and technical standards described herein are incorporated by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference.

Claims

1. This sensor connector irradiates a sample containing the substance whose physical properties are to be measured with measurement light incident from a spectroscopic analyzer, captures the reflected light from the sample, and outputs it to the spectroscopic analyzer. The optical system comprises a flat surface on which the measurement light is emitted and in contact with the sample. Sensor connector.

2. The sensor connector according to claim 1, wherein the optical system has an aspherical incident surface for the measurement light.

3. The sensor connector according to claim 2, wherein the optical system has a linear outer peripheral surface parallel to the optical axis when viewed from a lateral direction perpendicular to the optical axis.

4. The sensor connector according to claim 2, wherein the optical system is formed by joining an aspherical lens composed of an aspherical surface and a planar surface with a planar plate lens composed of a planar surface.

5. The aforementioned sample is a fluid, The sensor connector according to claim 1, which is detachably provided in a fluid passage through which the fluid flows.

6. The sensor connector according to claim 1, wherein the distance between the point where the optical axis intersects the emission surface and the focusing position of the measurement light is 0.3 mm or more and 7.5 mm or less.

7. The sensor connector according to claim 6, wherein the aforementioned distance is 2 mm or less.

8. The sensor connector according to claim 1, wherein the physical property data is Raman spectral data.

9. A measurement method for measuring physical property data, comprising connecting the sensor connector described in claim 1 to a flow cell having a channel through which a fluid sample flows.

10. The measurement method according to claim 9, wherein the fluid is a liquid derived from cell culture medium.

11. The measurement method according to claim 10, wherein the liquid comprises cell products as the substance.

12. The measurement method according to claim 10, wherein the liquid is obtained from a culture vessel during cultivation.

13. The measurement method according to claim 10, wherein the liquid is from which cells have been removed.

14. The measurement method according to claim 9, wherein the fluid includes cells.

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