Sensor unit and cell culture analysis apparatus equipped with the same

Abstract

A sensor unit (28) comprises a sensor (30), a probe (10a) and a probe holder (10). The probe (10a) abuts an electrode (31c) of a connecting terminal portion (31b) of the sensor (30) and applies a prescribed voltage. The probe holder (10) holds the probe (10a) such that the probe (10a) projects toward the connecting terminal portion (31b) of the sensor (30), and has an opposing surface (61) disposed opposing the connecting terminal portion (31b) of the sensor (30), wherein a non-capillary space (S1) communicating with a space faced by a plurality of mutually adjacent electrodes (31c) of the connecting terminal portion (31b) of the sensor (30) is formed between the opposing surface (61) and the connecting terminal portion (31b) of the sensor (30).

Description

Technical Field

[0001] The present invention relates to a sensor unit for analyzing cultured cells and a cell culture analysis apparatus including the same.

Background Art

[0002] In a conventional cell culture analysis apparatus, a measuring device is disposed inside an incubator, and while culturing cells in a state where a culture module with a sensor for culturing cells is set in the measuring device, the state of cell culture is measured with a glucose sensor (analysis of the culture state). For example, Patent Document 1 discloses a cell culture apparatus including a plurality of culture units including a canister disposed in a thermostat and a culture cassette stored in the canister.

[0003] In the cell culture apparatus disclosed in Patent Document 1, the culture cassette has a culture bag containing cells to be cultured and is inserted into the canister. Then, the cells in the culture bag are cultured in an independent culture environment for each canister.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] However, the above-described conventional cell culture apparatus has the following problems. That is, in the cell culture apparatus disclosed in the above publication, no consideration is given to the generation of leakage current due to dew condensation between measurement electrodes generated on the surface of a sensor used in a high-temperature and high-humidity environment. For example, when a sensor that was placed in an environment at room temperature (25 degrees) is immersed in a medium placed in a culture vessel and then placed in a high-temperature and high-humidity environment (37 degrees, humidity 90% or more) in an incubator, for some time, the surface of the sensor remains at a temperature close to room temperature and thus becomes lower than the temperature in the incubator. Therefore, on the surface of the sensor, the space between the measurement electrodes may be electrically connected by the condensed moisture, resulting in current leakage.

[0006] When such current leakage occurs between the measurement electrodes, in a cell culture analysis apparatus that measures minute currents for analyzing cell culture and the like, there is a risk that various measurements cannot be accurately performed. An object of the present invention is to provide a sensor unit capable of effectively suppressing the generation of leakage current caused by condensation even when used in a high-temperature and high-humidity environment, and a cell culture analysis apparatus equipped with the same. (Means for Solving the Problem) The sensor unit according to the first invention is a sensor unit for measuring components of a liquid sample placed in a culture vessel, and includes a sensor, a connection part, and a connection part holder. The sensor includes a main body part, a detection part disposed on the main body part and immersed in the liquid sample, and a connection terminal part including a plurality of electrodes that are electrically connected to the detection part and to which a predetermined voltage is applied when measuring the components of the liquid sample. The connection part abuts against the electrodes of the connection terminal part of the sensor to apply a predetermined voltage. The connection part holder holds the connection part so that the connection part protrudes toward the connection terminal part of the sensor, and has an opposing surface disposed opposite to the connection terminal part of the sensor. A non-capillary space is formed between the opposing surface and the connection terminal part of the sensor to communicate a space where a plurality of electrodes adjacent to each other of the connection terminal part of the sensor face. (Effect of the Invention) According to the sensor unit of the present invention, even when used in a high-temperature and high-humidity environment, the generation of leakage current caused by condensation can be effectively suppressed.

Brief Description of the Drawings

[0007]

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Embodiments for Carrying Out the Invention

[0008] The cell culture analysis apparatus 1 equipped with the sensor unit 28 according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 26 as follows. <Overview of the cell culture analysis apparatus 1> The cell culture analysis apparatus 1 electrochemically detects the concentration of a specific component (for example, glucose, lactic acid, etc.) contained in the culture medium X (see FIG. 9) with a part of the sensor 30 (see FIG. 8 etc.) immersed in the culture medium X (liquid sample) placed in the well plate 25 (see FIG. 7) including a plurality of wells (culture containers) 25a, and analyzes the culture state. As shown in FIG. 1, the cell culture analysis apparatus 1 includes an analysis unit 2, a culture incubator 3 on which the analysis unit 2 is placed in the internal space, and a control unit 4 that controls the analysis unit 2 and displays the analysis results. Further, the analysis unit 2 and the control unit 4 are connected by an electric cable 5.

[0009] The analysis unit 2 is set in the internal space by opening the transparent door 3a that is openably attached to the front of the culture incubator 3. And the control unit 4 connected to the analysis unit 2 via the electric cable 5 is arranged outside the culture incubator 3. Thereby, the user can prevent air pollution due to contamination in the culture incubator 3 by analyzing the culture state in the culture incubator 3 by the control unit 4 without opening and closing the door 3a of the culture incubator 3.

[0010] The analysis unit 2 is designed to be short in the horizontal (width) direction, low in the height direction, and long in the depth direction so that a plurality of units can be installed in the culture incubator 3. As shown in FIGS. 2 and 3, the analysis unit 2 includes a culture module 20 with a sensor, a main body 21, a drawer 22, and a lifting mechanism 23. Note that as shown in FIG. 1, the main body 21 is pre - placed in the culture incubator 3 and connected to the control unit 4 by the electric cable 5. When performing cell culture analysis, the assembled culture module 20 with sensors is set by the user on the main body 21 inside the culture incubator 3 as shown in FIG. 3.

[0011] The analysis unit 2 is configured to be lifted toward the probe holder (connection part holder) 10, which will be described later, by the lifting mechanism 23 with the culture module 20 with sensors drawn into the main body 21 by the drawer part 22. As shown in FIG. 4, for example, the culture module 20 with sensors is assembled after the well plate 25 is filled with the medium X (see FIG. 9) and seeded with cells in a safety cabinet C1 at room temperature (for example, air temperature of 25 degrees). The assembled culture module 20 with sensors is set in the analysis unit 2 inside the culture incubator 3 maintained at a high - temperature and high - humidity environment (37 degrees, humidity of 90% or more). That is, the assembled culture module 20 with sensors is moved from a room - temperature environment to a high - temperature and high - humidity environment (for example, air temperature of 37 degrees, humidity of 90% or more).

[0012] Note that the configuration for suppressing the generation of leakage current due to condensation that occurs when the culture module 20 with sensors moves from a room - temperature environment to a high - temperature and high - humidity environment will be described in detail later. As shown in FIGS. 5(a) and 5(b), the lifting mechanism 23 includes a mounting table 23a arranged inside the main body 21 and a link mechanism formed by connecting a plurality of arms 23b, 23c, 23d, 23e.

[0013] The mounting table 23a has the culture module 20 with sensors drawn into the internal space of the main body 21 by the drawer part 22 that can advance and retreat with respect to the external space from the main body 21 placed thereon, and moves up and down when the link mechanism is driven. Specifically, in the lifting mechanism 23, when the arm 23c is driven counterclockwise in the figure by a drive unit (not shown), the right end in the figure of the arm 23b connected via the arm 23d connected to the other end side of the arm 23c with one end as the rotation center is pushed down. At this time, the left end in the figure of the arm 23b is connected to the side surface of the mounting table 23a.

[0014] As a result, the arm 23b has its right end pushed down and its left end pushed up around the rotation center 23ba, so that the mounting table 23a on which the sensor-equipped culture module 20 is placed can be lifted upward. At this time, in the space above where the sensor-equipped culture module 20 in the analysis unit 2 is lifted, there is provided a probe holder 10 with a probe (connection part) 10a protruding downward.

[0015] As a result, the lifting mechanism 23 can lift the sensor-equipped culture module 20 so that the probe 10a abuts against the electrode 31c of the sensor 30 included in the sensor-equipped culture module 20. As shown in FIG. 6, the sensor-equipped culture module 20 is arranged in the order of an adapter bottom 24, a well plate 25, an adapter top 26, a bottom plate 27, a sensor 30, and a top plate 29 from below.

[0016] The adapter bottom 24 is connected to the adapter top 26 via a hinge part 24a, and holds the well plate 25 sandwiched between it and the adapter top 26. As shown in FIG. 7, the well plate 25 is configured to include a total of 24 wells (culture containers) 25a arranged in 4 rows and 6 columns vertically. The well plate 25 has several types including general-purpose products, and the adapter bottom 24 and the adapter top 26 are used appropriately according to the type.

[0017] The adapter top 26 is attached to the adapter bottom 24 via the hinge portion 24a so as to be openable and closable as described above. The adapter top 26 has through holes 41a provided in accordance with the positions of a plurality of wells 25a included in the well plate 25, and positioning through holes 41b provided at four flat corners. The through holes 41a are provided in four vertical rows and six horizontal rows in accordance with the positions of the 24 wells 25a included in the well plate 25. Each sensor 30 is immersed in the culture medium X in the well 25a through the through hole 41a.

[0018] The positioning of the plurality of sensors 30 with respect to the wells 25a is performed by inserting the leg portions 40 of the bottom plate 27, to which the plurality of sensors 30 are attached, into the through holes 41b. The bottom plate 27 is arranged to overlap the upper surface of the adapter top 26 with a plurality of sensors 30 attached to its upper surface (first surface). The sensor 30 is configured, for example, by forming a carbon electrode layer on the upper surface of a PET (polyethylene terephthalate) film, which is a resin material, by sputtering. And as shown in FIG. 8, the sensor 30 has a main body portion 31, a detection portion 31a, a connection terminal portion 31b, a bending portion 32, and a connecting portion 33.

[0019] The main body portion 31 is a substantially rectangular flat plate-shaped member, and is connected to the bending portion 32 at its upper end portion. As shown in FIG. 9, the detection portion 31a is provided on the surface of the wide portion at the lower end of the main body portion 31 having a substantially T-shaped downward, and includes measurement electrodes (working electrode, counter electrode, reference electrode). The detection portion 31a measures the concentration of a specific component (for example, glucose, lactic acid, etc.) contained in the culture medium X electrochemically by applying a predetermined voltage to each measurement electrode in a state of being immersed in the culture medium X placed in the well 25a.

[0020] Each measurement electrode included in the detection unit 31a is formed by evaporating the electrode layer with a laser and dividing it. Note that each measurement electrode may have an electrode pattern formed by screen printing in order to improve the insulation between wirings. Here, when measuring the concentration of glucose contained in the culture medium X, the reagent layer immobilized on the surface of the working electrode may contain, as glucose oxidase, for example, glucose oxidase (GOx), glucose dehydrogenase (GDH), and further a redox mediator.

[0021] The concentration of glucose is measured by converting the electrons generated by the oxidation reaction of the reduced form of the redox mediator or hydrogen peroxide, which is generated when glucose permeating from the culture medium X through the protective film is oxidized by the enzyme (e.g., GOx, GDH) in the reagent layer to form gluconolactone, into a current value. As shown in FIG. 8, the bending portion 32 is a portion connecting between the main body portion 31 and the connecting portion 33, and is bent substantially at a right angle along a predetermined bending line. Thereby, the connecting portion 33 is arranged substantially at a right angle with respect to the main body portion 31.

[0022] As shown in FIG. 8, the connecting portion 33 connects the upper end portions of the main body portions 31 of the four sensors 30 arranged in the lateral direction to each other via the bending portion 32. The connection terminal portion 31b has four electrodes 31c arranged corresponding to each measurement electrode of the detection unit 31a of one sensor 30 in a set of four. The four electrodes 31c are electrically connected to each measurement electrode (working electrode, counter electrode, reference electrode) included in the detection unit 31a arranged at the lower part of the main body portion 31 of the sensor 30.

[0023] As shown in FIG. 8, the plurality of sensors 30 included in the sensor unit 28 of the present embodiment include a main body portion 31, a detection unit 31a arranged on the lower end side of the main body portion 31 and immersed in the culture medium X to measure the components of the culture medium X, and a connecting portion 33 connecting the plurality of sensors 30 on the upper end side of the main body portion 31. As a result, the plurality of sensors 30 are attached to the upper surface of the bottom plate 27 while being connected to each other by the connecting portion 33, so that the positions of the sensors 30 connected to each other can be accurately defined.

[0024] Therefore, the positional accuracy (position, angle, etc.) of each sensor 30 with respect to the plurality of wells (culture vessels) 25a included in the well plate 25 can be improved. As a result, since the immersion depth of each sensor 30 in the medium X placed in the well 25a becomes substantially constant, stable measurement results can be obtained. As shown in FIGS. 6 and 10, the top plate 29 is disposed so as to cover the upper surface of the sensor 30 attached to the upper surface of the bottom plate 27. The top plate 29 has a pressing portion 29a that presses the upper side of the bent portion 32 of the sensor 30 downward and a through hole 29b.

[0025] Here, as shown in FIG. 10, the sensors 30 are stacked so as to be sandwiched between the upper surface of the bottom plate 27 and the lower surface of the top plate 29 in a state where the connecting portion 33 is bent. At this time, each sensor 30 is held between the support portion 27b on the bottom plate 27 side and the pressing portion 29a on the top plate 29 side as shown in FIG. 10.

[0026] That is, a support portion 27b that supports the lower side of the bent portion 32 of the sensor 30 is provided at the opening edge of the through hole 27a of the bottom plate 27. A pressing portion 29a that presses the upper side of the bent portion 32 of the sensor 30 downward is provided at a portion of the top plate 29 facing the support portion 27b. As a result, the upper surface of the sensor 30 is supported by the pressing portion 29a provided on the lower surface side of the top plate 29, and the lower surface of the sensor 30 is supported by the support portion 27b provided on the upper surface side of the bottom plate 27.

[0027] As shown in FIG. 10, the support portion 27b has an upper surface curved portion shape including a curved surface on the upper surface. Further, as shown in FIG. 10, the pressing portion 29a has a lower surface curved portion shape including a curved surface on the lower surface. As a result, as shown in FIG. 10, when the sensor 30 is sandwiched vertically between the top plate 29 and the bottom plate 27, the bent portion 32 of the sensor 30 is held in a state of being sandwiched vertically by the support portion 27b and the pressing portion 29a.

[0028] Therefore, since the bent angle of the sensor 30 is accurately defined, the detection portion 31a provided at the lower end portion of the main body portion 31 of the sensor 30 is arranged in a stable state. <Structure for suppressing generation of leakage current caused by moisture generated by condensation> Here, as described above, a configuration for suppressing the generation of leakage current caused by condensation that occurs when the culture module 20 with sensor is brought from a room temperature environment to a high temperature and high humidity environment will be described.

[0029] That is, when the culture module 20 with sensor assembled at room temperature (for example, air temperature 25 degrees) is set in the analysis unit 2 in the culture incubator 3 maintained in a high temperature and high humidity environment (37 degrees, humidity 90% or more), the surface of the sensor 30 close to room temperature becomes lower than the temperature in the culture incubator 3, and there is a possibility of condensation occurring on the surface of the sensor 30 (see FIG. 17). And when the electrodes 31c of the sensor 30 are connected by condensation, current leakage may occur, and there is a possibility that measurement using a minute current (analysis of cell culture) cannot be appropriately performed.

[0030] Therefore, the cell culture analysis apparatus 1 of the present embodiment suppresses the generation of leakage current by the following configuration. That is, as shown in FIGS. 6 and 8, in the culture module 20 with sensor, the top plate 29 has a plurality of through holes 29b provided in accordance with the positions of the connection terminal portions 31b of the respective sensors 30 as described above.

[0031] When viewed from the upper surface side of the top plate 29, as shown in FIG. 11, the connection terminal portions 31b of the plurality of sensors 30 attached to the upper surface of the bottom plate 27 are arranged so as to be exposed in the plurality of through holes 29b. That is, the connection terminal portions 31b are arranged at the bottom portions of the plurality of through holes 29b. Then, as shown in FIGS. 15 and 16, with the tip of the probe 10a described above in contact with the plurality of electrodes 31c constituting the connection terminal portion 31b through the through hole 29b of the top plate 29, a voltage is applied, whereby the medium X is measured by the measurement electrodes electrically connected to the respective electrodes 31c of the connection terminal portion 31b.

[0032] The probe 10a inserted into the through hole 29b is held, for example, by a probe holder 10 formed of resin. As shown in FIG. 12, the probe holder 10 is provided in a state integrated with the metal plate 12 such that a plurality of probes 10a project from the metal plate 12. As shown in FIG. 13, the probe holder 10 has a metal plate 12 attached to its lower surface side and a box-shaped probe box 10b having an upper opening on its upper surface side.

[0033] On the bottom surface of the probe box 10b, a substrate 11 to which a plurality of probes 10a are fixed by soldering is arranged. That is, as shown in FIG. 14, the plurality of probes 10a project from the bottom surface of the probe box 10b, and the substrate 11 is soldered in a state set on the bottom surface of the probe box 10b (see the portion of the broken-line circle in FIG. 16), thereby being electrically connected to the substrate 11.

[0034] Note that the upper and lower surfaces of the substrate 11 may be resin-molded for waterproof and moisture-proof purposes (see the portion hatched with dots in FIG. 16). When the probe holder 10 is set on the upper surface of the top plate 29 with a plurality of probes 10a fixed to the substrate 11 by soldering, as shown in FIG. 15, the tips of the plurality of probes 10a come into contact with the respective electrodes 31c included in the connection terminal portions 31b of the plurality of sensors 30.

[0035] That is, when the probe holder 10 in which a plurality of probes 10a project downward is held on the upper surface of the top plate 29, as shown in FIG. 16, the plurality of probes 10a are inserted into the through holes 29b of the top plate 29 and come into contact with the respective electrodes 31c constituting the connection terminal portions 31b of the plurality of sensors 30 arranged at the bottom portions of the through holes 29b. Note that the probe 10a is biased downward by a spring (not shown), moves upward by coming into contact with the electrode 31c, and the contact state with the electrode 31c is maintained.

[0036] At this time, as shown in FIG. 16, a predetermined space S1 is formed between the upper surface of the top plate 29 and the lower surface (metal plate 12) of the probe holder 10. The top plate 29 is provided with through holes 29b that communicate the predetermined space S1 side and the bottom plate 27 side. Thereby, the connection terminal portions 31b of the sensors 30 are exposed in the predetermined space S1 through the through holes 29b on the bottom plate 27.

[0037] Note that only the probe 10a that projects downward from the probe holder 10 exists in the space S1 formed between the upper surface of the top plate 29 and the lower surface of the probe holder 10. Here, the space S1 is formed such that, for example, its height is larger than the thickness of the top plate 29. Thereby, an open space S1 is formed above each electrode 31c that constitutes the connection terminal portion 31b to which a voltage is applied via the probe 10a.

[0038] Therefore, even when dew condensation occurs on the surface of the culture module 20 with a sensor when it is moved from a room temperature environment into the culture incubator 3 in a high temperature and high humidity environment, the breathability can be ensured by the open space S1. For this reason, the vicinity of the connection terminal portion 31b is easily adapted to a high temperature and high humidity environment, and the growth of the condensed moisture can be suppressed by the good breathability, and the electrical connection between the adjacent electrodes 31c can be suppressed.

[0039] As a result, the generation of leakage current due to dew condensation that occurs when the culture module 20 with a sensor is moved from a room temperature environment to a high temperature and high humidity environment can be suppressed, and highly accurate measurement can be performed. Further, in the configuration of the present embodiment, the probe holder 10 has a diameter-reduced portion 10c having an outer diameter smaller than that of its upper portion at a portion that holds the vicinity of the tips of the plurality of probes 10a.

[0040] Thereby, the volume of the tip portion of the probe holder 10 occupying the space S1 above each electrode 31c constituting the connection terminal portion 31b with which the tip of the probe 10a abuts is minimized, and the space S1 can be ensured as wide as possible. Therefore, the growth of the moisture condensed around the plurality of electrodes 31c constituting the connection terminal portion 31b of the sensor 30 can be prevented, and the generation of leakage current can be effectively suppressed.

[0041] Furthermore, in the present embodiment, the through hole 29b of the top plate 29 into which the probe 10a is inserted is formed so as to communicate the space above where two adjacent electrodes 31c face. That is, the through hole 29b is formed so that one hole covers the range of two electrodes 31c. Thereby, the space S1 formed above the electrode 31c can be opened wider, and the growth of the moisture condensed on the electrode surface on which the plurality of electrodes 31c are arranged can be effectively suppressed.

[0042] Further, as shown in Fig. 17(a), the electrodes 31c constituting the connection terminal portion 31b of the sensor 30 are provided such that the distance L between the electrodes 31c is larger than the width W of each electrode 31c. This increases the distance between the electrodes 31c, and by suppressing the water film formed by the condensed moisture from electrically connecting between the electrodes 31c, it is possible to suppress the leakage current from flowing between the electrodes 31c.

[0043] Furthermore, a water-repellent resist (water-repellent layer) 35 having water repellency is provided on the surface of the base material 34 (PET sheet) of the sensor 30. As a result, the moisture condensed on the electrode surface of the sensor 30 becomes spherical water droplets W1 due to the water repellency of the water-repellent resist 35, as shown in Fig. 17(b). Therefore, it is possible to effectively suppress the water droplets W1 from connecting between the electrodes 31c to form a water film and the leakage current from flowing.

[0044] Furthermore, the water-repellent resist 35 is formed such that its thickness is larger than the thickness of the electrode 31c. This can extend the creepage distance between the electrodes 31c and more effectively suppress the occurrence of leakage current between the electrodes 31c. In addition, since the surface of the electrode 31c is at a position lower than that of the water-repellent resist 35, it is possible to suppress the connection between the moisture condensed on the surface of the electrode 31c and the moisture condensed on the surface of the water-repellent resist 35.

[0045] Furthermore, the water-repellent resist 35 is provided with convex portions 35a protruding upward at the edge portions adjacent to the outer peripheral portion of the electrode 31c. This can suppress the connection with the electrode 31c side by retaining the moisture condensed on the surface of the water-repellent resist 35 on the surface of the water-repellent resist. Note that the convex portions 35a formed at the edge portions of the water-repellent resist 35 may be formed, for example, by utilizing the step formed in the punching cross-section when punching out the water-repellent resist 35 formed on the base 52 using a pinnacle (common name) 51, as shown in Fig. 18.

[0046] Alternatively, as shown in Fig. 19(a), with the resist material R1 placed in the mold 53 positioned on the base 55, the water-repellent resist 35 may be formed by screen printing while pressing the plate material 54 against the upper surface of the mold 53 as shown in Fig. 19(b). In this case, as shown in Fig. 19(b), when lifting the mold 53 from the base 55, the protruding portion formed at the end of the water-repellent resist 35 due to the saddle phenomenon may be used as the convex portion 35a.

[0047] Such a protruding portion will naturally bulge at both ends due to the saddle phenomenon as the water-repellent resist 35 becomes thicker, so the bulged portion can be utilized as the convex portion 35a. <Main features> In order to suppress the generation of leakage current caused by condensation and perform appropriate analysis, the sensor unit 28 of this embodiment includes a sensor 30, a bottom plate 27, a top plate 29, and a probe holder 10 as shown in Fig. 16. The sensor 30 has a connection terminal portion 31b including a detection portion 31a and a plurality of electrodes 31c that are electrically connected and to which a predetermined voltage is applied when measuring the components of the culture medium X. The bottom plate 27 has an upper surface to which the connection terminal portion 31b is attached and a lower surface opposite to the upper surface. The top plate 29 has a through hole 29b into which a probe 10a for applying a predetermined voltage in contact with the plurality of electrodes 31c is inserted, and is arranged so as to sandwich the connection terminal portion 31b together with the bottom plate 27. The probe holder 10 holds the probe 10a so that the probe 10a protrudes toward the connection terminal portion 31b, and has a metal plate 12 disposed opposite to the connection terminal portion 31b of the sensor 30, and is arranged so that a predetermined space S1 is formed between the lower surface of the metal plate 12 and the top plate 29.

[0048] As a result, dew condensation occurs on the surface of the sensor unit 28 placed in a high-temperature and high-humidity environment from a room-temperature environment, but a predetermined space S1 is formed in a portion facing the connection terminal portion 31b including the plurality of electrodes 31c. For this reason, as shown in Fig. 20(a), it is possible to suppress the growth of moisture (water droplets W1) condensed on the surface of the sensor 30 until it electrically connects between the electrodes 31c.

[0049] Therefore, even when used in a high-temperature and high-humidity environment, as shown in Fig. 20(b), it is possible to effectively suppress the leakage current generated when the moisture condensed between the electrodes 31c becomes a water film W2, and various measurements related to the analysis of cell culture can be accurately performed. The main part of the sensor unit 28 of the present embodiment will be further described in detail below. Fig. 21(a) shows a cross-sectional view of the sensor unit 28 immediately before replacing the used sensor 30.

[0050] The sensor unit 28 of the present embodiment is a device that constitutes the cell culture analysis apparatus 1 disposed in the culture incubator 3. The sensor unit 28 is configured to include a disposable part (a member below the broken line in Fig. 21(a)) and a reusable part (a member above the broken line in Fig. 21(a)). The cell culture analysis apparatus 1 measures the metabolic components of the culture medium using the sensor unit 28 while culturing target cells in the culture medium in a plurality of wells (culture containers) 25a in the culture incubator 3, and estimates the culture state of the cells. When replacing the target cells, the well (culture container) 25a of the sensor unit 28 and the part mainly composed of the sensor 30 are replaced, and the connection part (a member above the broken line in the figure) electrically connected to the other sensors 30 is reused.

[0051] The disposable part (below the broken line in the figure) mainly includes the sensor 30, the culture medium 60 as a liquid sample in which the detection part 31a of the sensor 30 is immersed for measurement, and the well (culture container) 25a that holds the culture medium. The reuse part (above the dashed line in the figure) mainly includes a probe (connection part) 10a that directly contacts the electrode 31c of the connection terminal part 31b of the sensor 30 and a probe holder (connection part holder) 10.

[0052] Here, the disposable part and the reuse part are detachably configured, and the user performs the replacement operation of the disposable part in the culture incubator 3. As described above, the inside of the culture incubator 3 is an environment of high temperature and high humidity (37 °C, humidity 90%). In such an environment of high temperature and high humidity, when replacing the disposable part, the disposable part is in a state of being stored in a refrigerator or at room temperature immediately before the start of use. Therefore, in the environment of high temperature and high humidity inside the culture incubator 3, due to the temperature difference between the inside of the culture incubator 3 and the disposable member, condensation is likely to occur on the disposable member.

[0053] In addition, if the reuse part is not allowed sufficient time to adapt to the internal temperature after being installed in the culture incubator 3, there is a risk of condensation occurring on their surfaces. In particular, the probe 10a included in the reuse part is formed of a conductive metal and has a large heat capacity, so it takes time for the temperature to adapt to the inside of the culture incubator 3, and thus moisture is likely to adhere. For this reason, if the reuse part is used in the culture incubator 3 without allowing sufficient time after installation, a large amount of condensed probe 10a and the electrode 31c, which is still close to room temperature, will be electrically connected.

[0054] As a result, after replacing the disposable part, there is a risk of short - circuit or leakage current occurring between the electrical contacts due to the moisture adhering to the reuse part and the occurrence of condensation accompanying the temperature change in the disposable part. If the connection terminal portion 31b of the sensor 30, which is an electrical contact portion, and the probe 10a that abuts against the connection terminal portion 31b are sealed with a waterproof structure, when replacing, the moisture adhering to the reusable (reuse) portion will be sealed within the waterproof structure. Therefore, the possibility of short - circuit or leakage current occurring between electrical contacts due to the sealed moisture is further increased.

[0055] Therefore, in the sensor unit 28 of the present embodiment, the periphery of the connection terminal portion 31b of the sensor 30, which is an electrical contact portion, and the probe 10a that abuts against the connection terminal portion 31b is open to the atmosphere of the culture incubator 3. As a result, even when condensation occurs, the moisture generated at that time can be dried by the circulating air flow within the culture incubator 3.

[0056] FIG. 21(b) shows a cross - sectional view of the sensor unit 28 after the sensor 30 is replaced. As shown in FIG. 21(b), the sensor unit 28 measures the components of the culture medium 60 in a state where the lower end portion of the sensor 30 is immersed in the culture medium 60 as a liquid sample placed in the well (culture vessel) 25a. Here, the configuration of the disposable portion of the sensor unit 28 will be described.

[0057] As shown in FIG. 8, the sensor 30 has a main body portion 31, a detection portion 31a disposed on the main body portion 31 and immersed in the culture medium 60, and a connection terminal portion 31b including a plurality of electrodes 31c (see FIG. 11) that are electrically connected to the detection portion 31a and to which a predetermined voltage is applied when measuring the components of the culture medium 60. Next, the configuration of the reusable portion of the sensor unit 28 will be described.

[0058] The probe 10a applies a predetermined voltage to the connection terminal portion 31b while being in contact with the connection terminal portion 31b of the sensor 30. The probe holder 10 holds the upper portion of the probe 10a so that the probe 10a protrudes toward the connection terminal portion 31b of the sensor 30. Further, the probe holder 10 has a facing surface 61 disposed to face the connection terminal portion 31b of the sensor 30. Therefore, a space S1 is formed between the facing surface 61 and the connection terminal portion 31b of the sensor 30, which communicates the spaces facing a plurality of electrodes 31c adjacent to each other of the connection terminal portion 31b of the sensor 30.

[0059] As described above, the probe holder 10 holds the probe 10a so that the probe 10a protrudes toward the connection terminal portion 31b. Therefore, a predetermined height is formed between the facing surface 61 and the connection terminal portion 31b of the sensor 30, and thus the space S1 becomes a non-capillary space where capillary action does not act on the liquid near the space S1. Since the space S1 is a non-capillary space, moisture is not sucked between the facing surface 61 and the connection terminal portion 31b of the sensor 30. Therefore, it is possible to prevent extra moisture from entering the periphery of the connection terminal portion 31b due to capillary action.

[0060] The space S1 is configured to be a space open to the outside of the apparatus in a substantially horizontal direction in the cell culture analyzer 1. Thereby, a circulating air flow in the culture incubator 3 also occurs in the space S1. Therefore, since the space facing a plurality of electrodes 31c adjacent to each other of the connection terminal portion 31b of the sensor 30 is communicated in the substantially horizontal direction by the space S1, moisture generated around the plurality of electrodes 31c can be evaporated and dried. As a result, short circuits between electrical contacts and leakage current can be effectively prevented.

[0061] FIG. 22 shows a perspective view of the probe 10a and the probe holder 10 with the probe 10a facing upward. Here, in the connection terminal portion 31b on the sensor 30 side with which the probe 10a abuts, four electrodes 31c are provided for each sensor 30. Similarly, as shown in FIG. 22, the probes 10a are also provided in groups of four, and are provided in four rows in the X direction and six columns in the Y direction.

[0062] Then, a plurality of adjacent probes 10a are provided in a mutually communicating space. Also, the plurality of probes 10a are provided in a space open to the outside of the apparatus so that air circulating in the direction indicated by the arrow can easily flow with respect to the X direction and Y direction in FIG. 22 (i.e., the substantially horizontal direction of the apparatus in the use state). As a result, in the space S1, the space where a plurality of mutually adjacent electrodes 31c included in the connection terminal portion 31b of the sensor 30 and a plurality of mutually adjacent probes 10a of the probe holder 10 face each other is communicated. Therefore, moisture generated around the plurality of electrodes 31c and the plurality of probes 10a corresponding thereto can be evaporated and dried, and the occurrence of short circuits and leakage currents between electrical contacts can be effectively prevented.

[0063] FIG. 23 shows a cross-sectional view of a state in which the sensor 30 placed on the well plate 25 and the probe holder 10 are set. As shown in FIG. 23, the probe 10a is directly visible from the side surface of the apparatus, that is, since the space S1 is an open space in the substantially horizontal direction of the apparatus in the use state, it serves as a passage for the circulating air flow of the culture incubator 3.

[0064] Furthermore, moisture generated around the plurality of electrodes 31c provided in the space communicated in the space S1 and the plurality of probes 10a corresponding thereto is effectively evaporated and dried by the circulating air flow. As a result, the occurrence of short circuits and leakage currents between electrical contacts can be effectively prevented. FIG. 24(a) shows a perspective view of the connection terminal portion 31b of the sensor 30.

[0065] FIG. 24(b) shows a cross-sectional view taken along the line A - A' of the connection terminal portion 31b in FIG. 24(a). As shown in FIGS. 24(a) and 24(b), the plurality of electrodes 31c included in the connection terminal portion 31b are arranged such that the interval between adjacent electrodes 31c is larger than the width of the electrode 31c. Further, it is composed of the electrode 31c portion and the water-repellent resist 35 portion between the electrodes 31c, 31c. However, the portion of the electrode 31c is located at a lower position than the portion of the water-repellent resist 35 between the electrodes 31c, 31c. As a result, the electrode 31c is disposed in the recess formed in the base material 34, and the portion of the water-repellent resist 35 between the electrodes 31c, 31c is formed on the convex portion of the base material 34.

[0066] That is, the length of the water-repellent resist 35 in the substantially horizontal direction is larger than the length of the electrode 31c in the substantially horizontal direction, and the thickness of the water-repellent resist 35 is larger than the thickness of the electrode 31c. As a result, the moisture generated by condensation accumulates in the recess of the base material 34 where the electrode 31c is provided, so that the occurrence of a short circuit or leakage current between the electrodes 31c, 31c can be effectively prevented. In addition, since the length of the water-repellent resist 35 in the substantially horizontal direction is larger than the length of the electrode 31c in the substantially horizontal direction, a sufficient distance between the electrodes 31c, 31c can be ensured, and the occurrence of a short circuit or leakage current between the electrodes 31c, 31c can be effectively prevented.

[0067] FIG. 25(a) shows an enlarged cross-sectional view of the sensor unit 28 immediately before replacing the used sensor 30. Sodium, potassium, chlorine, etc. adhere to the probe 10a due to long-term use. Therefore, dew condensation water W3 to which a leakage current in which an electrolyte component is eluted easily flows adheres to the probe 10a. Further, dew condensation water W3 also adheres to the connection terminal portion 31b of the lower sensor 30.

[0068] Here, the probe 10a is biased downward in the figure by an elastic member such as a spring and slides inside the probe holder 10 by contacting the electrode 31c. As a result, even when the heights of the plurality of electrodes 31c vary, the probe 10a can absorb the variation in the position and obtain a stable electrical connection. On the other hand, when the probe 10a and the electrode 31c are electrically connected, the probe 10a slides so as to enter the inside of the smaller-diameter portion 10c of the probe holder 10. Therefore, the condensed water W3 containing the electrolyte component attached to the probe 10a is scraped off toward the electrode 31c by the lower end of the smaller-diameter portion 10c.

[0069] Therefore, as shown in FIG. 25(b), in a state where the probe 10a and the electrode 31c are electrically connected (sensor unit 28 after replacing the sensor 30), a plurality of condensed water droplets W3 attached to the probe 10a are scraped off by the lower end of the smaller-diameter portion 10c, aggregate on the electrode 31c, and form a single droplet. As shown in FIG. 25(b), the diameter of the tip of the probe 10a in contact with the electrode 31c is smaller than the radial size of the electrode 31c.

[0070] Thereby, the condensed water W3 aggregated by the above-described sliding operation can be held in the recess provided with the electrode 31c. As a result, it is possible to effectively prevent the occurrence of a short circuit or leakage current between the electrodes 31c and 31c due to condensation. In addition, as described above, the probe holder 10 has a smaller-diameter portion 10c on the lower end portion (first end portion) on the electrode 31c side in the portion holding the probe 10a, and the outer diameter of holding the probe 10a is smaller than that on the upper end portion (second end portion) side opposite to the lower end portion.

[0071] Thereby, a gap 63 can be formed between the smaller-diameter portion 10c and the electrode 31c. As a result, even when the amount of the condensed water W3 increases, a large adsorption force due to the meniscus (liquid bridge) generated in the gap 63 can hold a large amount of moisture in the gap 63. Therefore, it is possible to effectively prevent the occurrence of a short circuit or leakage current between the electrodes 31c and 31c.

[0072] FIG. 25(c) shows an enlarged view of the tip of the probe 10a. The probe 10a has a crown shape including a plurality of sharp protrusions 10aa at its tip. As a result, the sharp protrusions 10aa can penetrate the oxide film formed on the surface of the electrode 31c or the probe 10a, ensuring electrical connection between the electrode 31c and the probe 10a.

[0073] Furthermore, for example, it is possible to effectively prevent the occurrence of poor electrical connection caused by the intrusion of dust (detached fibers) adhering to the probe 10a due to long-term use. Also, even when the electrode 31c is a material such as carbon or solder that is easily transferred, the self-cleaning effect can prevent these materials from depositing on the tip of the probe 10a.

[0074] Here, the probe 10a is preferably formed of a highly corrosion-resistant material such as a SUS alloy, Pd alloy, palladium, rhodium, iridium, tungsten, titanium, etc. that is resistant to moisture corrosion. Thereby, even when electrical connection is made in an environment where high-temperature and high-humidity contact failure occurs in the culture incubator 3, a highly reliable electrical connection can be achieved.

[0075] FIG. 26 shows a graph of the relationship between the elapsed time when replacing the disposable sensor 30 and the temperature of the disposable part including the sensor 30. After replacing with a new sensor 30, dew condensation occurs on the surface of the disposable part including the new sensor 30 until it reaches the outdoor temperature in the process of gradually approaching the temperature in the culture incubator 3 in a high-temperature and high-humidity environment. In this process, as described above, moisture such as dew condensation water W3 is actively drawn into the recess where the electrode 31c of the connection terminal portion 31b is provided.

[0076] After the disposable part including the sensor 30 reaches the temperature inside the culture incubator 3, as described above, the moisture in the space S1 open to the outside evaporates and dries due to the circulating air flow along the substantially horizontal direction formed inside the culture incubator 3. As a result, moisture such as the condensed water W3 generated in the space S1 grows before the sensor unit 28 reaches the outdoor temperature, but after reaching the outdoor temperature, the generated condensed water and the like can be evaporated and dried by the circulating air flow generated inside the culture incubator 3.

[0077] As a result, it is possible to effectively prevent the occurrence of a short circuit or leakage current between the electrodes 31c, 31c disposed in the space S1. As described above, in the sensor unit 28 of the present embodiment, after replacing the sensor 30, the occurrence of a short circuit or leakage current between the electrodes 31c, 31c can be effectively prevented by the above-described two-stage contrivance (holding of the condensed water W3, evaporation / drying).

[0078] [Other Embodiments] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention. (A) In the above embodiment, an example has been described in which a water-repellent resist 35 having water repellency is formed on the electrode surface on which a plurality of electrodes 31c constituting the connection terminal portion 31b of the sensor 30 are arranged. However, the present invention is not limited to this.

[0079] For example, the configuration may be such that the electrode surface where the connection terminal portion is provided does not have a water-repellent layer. However, as described in the above embodiment, from the viewpoint of suppressing the occurrence of leakage current between the electrodes by making the condensed moisture into water droplets and making it difficult to form a water film by providing a water-repellent layer on the electrode surface, a configuration provided with a water-repellent layer is more preferable. (B) In the above-described embodiment, an example has been described in which the through-hole 29b of the top plate 29 into which the probe 10a is inserted is formed so as to communicate the upper spaces facing the two adjacent electrodes 31c. However, the present invention is not limited to this.

[0080] For example, the through-holes of the top plate may be provided one by one for each electrode, or may be provided one by one for three or more electrodes. (C) In the above-described embodiment, an example has been described in which the upper ends of the four sensors 30 are connected by the connecting portion 33 so that the four sensors 30 form a set. However, the present invention is not limited to this.

[0081] For example, the number of sensors connected by the connecting portion may be three or less, or may be five or more. In any case, since the positions between the sensors connected to each other are accurately defined, the position accuracy of the sensors can be improved. (D) In the above-described embodiment, an example has been described in which the sensor 30 is used in a bent state at the bent portion 32. However, the present invention is not limited to this.

[0082] For example, the sensor may be used without being bent. Even in this case, by adopting a configuration in which a plurality of sensors are connected by a connecting portion at the upper end portion of the main body portion of the sensor, the same effect as described above of improving the position accuracy of the sensors can be obtained. (E) In the above-described embodiment, an example has been described in which the sensor 30 having a substantially T-shaped reverse is used. However, the present invention is not limited to this.

[0083] For example, a sensor having a substantially I-shaped or substantially L-shaped may be used. (F) In the above-described embodiment, an example was given in which the culture module 20 with a sensor, which had been placed in an environment at room temperature (25 degrees), was placed in a high-temperature and high-humidity environment (37 degrees, humidity 90% or more) inside the culture incubator 3. However, the present invention is not limited to this.

[0084] For example, the environment in which it is placed before being placed in a high-temperature environment is not limited to room temperature, and it may be an environment suitable for the pretreatment of the sensor module before culturing. Alternatively, even when the sensor module that has been pretreated in a temperature environment lower than room temperature is placed in an environment at room temperature or a high-temperature and high-humidity environment higher than room temperature, the same effects as described above can be obtained.

Industrial Applicability

[0085] Since the sensor unit of the present invention can effectively suppress the generation of leakage current caused by condensation even when used in a high-temperature and high-humidity environment, it can be widely applied to various sensor units used for cell culture analysis.

Explanation of Reference Numerals

[0086] 1 Cell culture analyzer 2 Analysis unit 3 Culture incubator 3a Door 4 Control unit 5 Electric cable 10 Probe holder (connection part holder) 10a Probe (connection part) 10aa Protrusion 10b Probe box 10c Small-diameter part 11 Substrate 12 Metal plate 20 Culture module with sensor 21 Main body part 22 Draw-out part 23 Lifting mechanism 23a Mounting table 23b, 23c, 23d, 23e Arm 23ba pivot center 24 adapter bottom 24a hinge part 25 well plate 25a well (culture vessel) 26 adapter top 27 bottom plate 27a through-hole 27b support part 28 sensor unit 29 top plate 29a pressing part 29b through-hole 30 sensor 31 main body part 31a detection part 31b connection terminal part 31c electrode 32 bending part 33 connecting part 34 base material (PET sheet) 35 water-repellent resist (water-repellent layer) 35a convex part 40 leg part 41a through-hole 41b through-hole 51 pinnacle 52 base 53 formwork 54 plate material 55 base 60 culture medium 61 opposing surface 62 gap 63 gap C1 safety cabinet L distance R1 resist material S1 space W width W1 water droplet W2 water film W3 condensed water X culture medium

Claims

1. A sensor unit for measuring components of a liquid sample placed in a culture container, comprising: a main body; a detection part disposed on the main body and immersed in the liquid sample; and a connection terminal part including a plurality of electrodes that are electrically connected to the detection part and to which a predetermined voltage is applied when measuring the components of the liquid sample. a connection part that contacts the electrodes of the connection terminal part of the sensor and applies a predetermined voltage; a connection part holder that holds the connection part so that the connection part protrudes toward the connection terminal part of the sensor, and that has an opposing surface disposed opposite to the connection terminal part of the sensor, and forms a non-capillary space that communicates the space facing the plurality of electrodes adjacent to each other of the connection terminal part of the sensor between the opposing surface and the connection terminal part of the sensor; A sensor unit comprising the above.

2. The connection part holder has a diameter-reduced part on a first end on the electrode side in a part that holds the connection part, the outer diameter of which for holding the connection part is smaller than that of a second end on the opposite side of the first end. The sensor unit according to Claim 1.

3. A plurality of the diameter-reduced parts are provided in a one-to-one correspondence with the plurality of connection parts. The sensor unit according to Claim 2.

4. The non-capillary space is a space that is open to the outside in a substantially horizontal direction in a usage state. The sensor unit according to Claim 1.

5. The sensor is a disposable member, the connection part and the connection part holder are reusable members, and the sensor is configured to be detachable from the connection part and the connection part holder. The sensor unit according to Claim 1.

6. The plurality of electrodes included in the connection terminal part are arranged such that the distance between adjacent electrodes is larger than the width of the electrodes. The sensor unit according to Claim 1.

7. The connection part has a crown shape including a plurality of protrusions at the tip. The sensor unit according to Claim 1.

8. The material of the connection part includes any one of SUS alloy, Pd alloy, palladium, rhodium, iridium, tungsten, and titanium. The sensor unit according to Claim 1.

9. The sensor further includes a water-repellent layer formed on an electrode surface on which the electrodes of the sensor are arranged and having water repellency. The sensor unit according to Claim 1.

10. The thickness of the water-repellent layer is larger than the thickness of the electrodes. The sensor unit according to claim 9.

11. The plurality of electrodes are provided in a recess formed by a difference in thickness between the water-repellent layer and the electrodes. The sensor unit according to claim 10.

12. The water-repellent layer has a convex portion protruding in a direction away from the electrodes at an edge portion adjacent to the electrodes. The sensor unit according to claim 10 or 11.

13. The diameter of the connection portion that contacts the plurality of electrodes is smaller than the diameter of the electrodes. The sensor unit according to claim 10 or 11.

14. A connecting portion for connecting a plurality of the sensors on the upper end side of the main body portion; A bent portion where a plurality of the sensors are bent such that the connecting portion is bent with respect to the main body portion along a bent line substantially parallel to the longitudinal direction of the connecting portion; further comprising. The sensor unit according to claim 1.

15. Comprising the sensor unit according to claim 1, Cell culture analysis apparatus.

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