JP2020038233A - Capillary electrophoresis device - Google Patents

Abstract

To balance miniaturization with performance to cause no discharge even in a component configuration in which a creeping distance and a space distance cannot be sufficiently secured in a capillary electrophoresis device.SOLUTION: An electrophoresis device for analyzing a sample by electrophoresis includes: a capillary 02; a heater 62 as a heat source; a conductive member 63 at least a part of which is made of metal; and a heater assembly 60 for heating the capillary. The conductive member 63 is brought into contact with a ground section and subjected to insulation processing.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an electrophoresis apparatus using a capillary, and more particularly to a technique for reducing the size and reducing the risk of discharge.

  In recent years, the application range of DNA analysis has rapidly expanded from research use to clinical fields such as hospitals. As a means of DNA analysis, there is a method of separating a DNA fragment of a sample by electrophoresis, which is used for criminal investigation, determination of blood relation, and diagnosis of disease.

  In capillary electrophoresis, charged DNA is separated for each base length by applying a high voltage to a capillary filled with a separation medium at a constant temperature. The base sequence of the sample can be read by irradiating the capillary with excitation light and detecting the fluorescence emitted from the fluorescent dye label of the DNA passing through the capillary.

  In recent years, demands have been diversified with the diversification of various users. One is miniaturization of the device, and the other is to obtain the results of DNA analysis as soon as possible.

  As for the miniaturization of the apparatus, it is conceivable to actively reduce the excess space inside the apparatus and reduce the size of the apparatus itself. If a conductive component having a potential difference exists near the cathode end of the capillary, there is a possibility that a discharge may occur in nearby components other than the capillary. Therefore, in a conventional capillary electrophoresis apparatus, a design has been made such that a conductive component is not disposed near the cathode end of the capillary in order to avoid discharge. However, if the device is miniaturized, the cathode end of the capillary and the conductive component are inevitably arranged close to each other, and the possibility of discharge increases.

  This is a problem that is also mentioned in Patent Document 1. In Patent Document 1, even when a conductive component is arranged near the cathode end of the capillary, the spatial distance and creepage distance from the electrode of the capillary to the conductive component are reduced. A structure that increases the size is disclosed.

  On the other hand, with regard to speeding up the DNA analysis, a method of shortening the time required to start electrophoresis and a method of increasing the electrophoresis speed itself are conceivable. Patent Literature 2 discloses an electrophoresis apparatus including a capillary, a support on which the capillary is arranged on the surface, a temperature control heater that directly contacts the capillary, an optical system, and a high-voltage power supply. With the structure in which the capillary is brought into direct contact with the heater, the time required to raise the temperature to a predetermined temperature during electrophoretic analysis can be reduced.

  Patent Document 2 is an effective means for shortening the time required until capillary electrophoresis is started, thereby speeding up the analysis result. In addition, as one of the methods for speeding up the capillary electrophoresis to accelerate the analysis result, for example, increasing the voltage applied to the capillary is one of the methods. However, if the applied voltage is increased, the above-mentioned potential difference is further increased, and this may also cause a possibility that electric discharge occurs in components other than the capillary.

JP 2010-249579 A JP 2006-284530 A

  As described above, in realizing the demand for downsizing the capillary electrophoresis apparatus and increasing the speed of DNA analysis, measures common to both of them include measures against a discharge phenomenon. If the voltage applied to the capillary is increased, the risk of discharge to nearby components also increases. To reduce this, it is necessary to increase the spatial distance and creepage distance from the high voltage part to the nearby conductive parts, but simply increasing the distance increases the internal capacity of the device, Conflicts with the miniaturization of

  As a method of increasing the creepage distance, a method of processing a part corresponding to the creepage distance into a complicated shape to increase the surface area is often used. This is a method of increasing the creepage distance by providing irregularities even where a simple surface shape is sufficient. However, the risk of discharge increases or decreases depending on the presence or absence of cutting traces, molding traces, and the like on the surface of the component, and the state of the ambient temperature and humidity in the apparatus. Also, due to a phenomenon called tracking, a place where a discharge has occurred once may easily become a state of recurrence as a discharge path, and it is difficult to take measures against the discharge only by complicating the components.

  In addition to simply keeping the distance, a method of insulating by closing the space is also used. If the electrodes of the capillary are spatially shielded from the outside, it is easy to block the space including the high voltage part. However, since the capillary is a consumable and a component that must be replaced after performing a certain number of electrophoresis, the capillary electrode must also be in a space accessible to the replacing user, Spatial isolation is also difficult.

  An object of the present invention is to solve the above-mentioned problems and to provide a capillary electrophoresis apparatus in which a discharge risk is reduced even in a component configuration in which a creepage distance and a space distance cannot be sufficiently obtained.

  To achieve the above object, in the present invention, an electrophoresis apparatus that has a capillary and analyzes a sample by electrophoresis has a heater as a heat source and a conductive member at least partially made of a metal, An electrophoretic device is provided, wherein the conductive member is in contact with a ground portion and is insulated.

  According to the present invention, it is possible to provide a capillary electrophoresis apparatus in which a discharge risk is reduced in a component configuration in which a creepage distance and a space distance cannot be sufficiently obtained.

FIG. 1 is a schematic diagram showing one configuration of a capillary electrophoresis device according to each embodiment. FIG. 2 is a top view of the capillary electrophoresis apparatus of FIG. AA sectional drawing of the apparatus of FIG. FIG. 2 is a diagram illustrating one configuration of a capillary cartridge according to the first embodiment. FIG. 2 is an exploded view of the capillary cartridge according to the first embodiment. FIG. 3 is a schematic diagram of mounting the capillary cartridge according to the first embodiment. FIG. 2 is a configuration diagram of the vicinity of the capillary in which the risk of discharge is reduced according to the first embodiment. FIG. 3 is a diagram illustrating an example of a shape of a conductive member according to the first embodiment. FIG. 3 is a configuration diagram for explaining an insulating process of the conductive member according to the first embodiment. FIG. 9 is a configuration diagram near a capillary in which a discharge risk is reduced according to the second embodiment. FIG. 9 is a configuration diagram near a capillary in which a discharge risk is reduced according to a third embodiment. FIG. 9 is a configuration diagram near a capillary in which a discharge risk is reduced according to a fourth embodiment. FIG. 9 is a diagram illustrating a graph 1 for explaining effects of the configuration of the third embodiment. FIG. 9 is a diagram illustrating a graph 2 for explaining effects of the configuration of the third embodiment. FIG. 9 is a diagram illustrating a graph 3 for explaining effects of the configuration of the third embodiment. FIG. 14 is a diagram illustrating a graph 4 for explaining effects of the configuration of the third embodiment.

  Hereinafter, various embodiments of the present invention will be described with reference to the drawings. In all the drawings for describing various embodiments, components having the same function are denoted by the same reference numerals.

  Embodiment 1 Embodiment 1 is an embodiment of a capillary electrophoresis apparatus in which a discharge risk is reduced even in a component configuration in which a creepage distance and a space distance cannot be sufficiently obtained. That is, Example 1 is a capillary electrophoresis apparatus that analyzes a sample by electrophoresis using a capillary, and includes at least one heater for heating the capillary, an electrode holder for holding the capillary electrode and connecting to the high-voltage section. This is an embodiment of the electrophoresis apparatus in which the portion is made of metal, includes a conductive member grounded to a low potential, and the electrode holder and the conductive member are in contact with each other by a structure, and the structure is an insulating member. The first embodiment will be described below with reference to FIGS.

  FIG. 1 illustrates a configuration example of the capillary electrophoresis apparatus according to the first embodiment. The present apparatus can be roughly divided into two units, an irradiation detection / constant temperature bath unit 40 at the upper part of the apparatus and an autosampler unit 20 at the lower part of the apparatus.

  In an autosampler unit 20 as an injection mechanism, a Y-axis driving body 23 is mounted on a sampler base 21 and can be driven in the Y-axis. The Z-axis driving body 24 is mounted on the Y-axis driving body 23, and can drive on the Z-axis. A sample tray 25 is mounted on the Z-axis driving body 24, and a user sets an electrophoresis medium container 28, an anode-side buffer solution container 29, a cathode-side buffer solution container 33, and a sample container 26 on the sample tray 25. . The sample container 26 is set on the X-axis driving body 22 mounted on the sample tray 25, and only the sample container 26 can be driven on the sample tray 25 in the X-axis. A liquid feeding mechanism 27 is also mounted on the Z-axis driving body 24. The liquid feeding mechanism 27 is disposed below the electrophoresis medium container 28.

  The irradiation detection / constant temperature bath unit 40 includes a constant temperature bath unit 41 as a constant temperature bath and a constant temperature bath door 43, and the inside thereof can be maintained at a constant temperature. An irradiation detection unit 42 serving as a detection unit is mounted behind the thermostat unit 41, and can perform detection during electrophoresis. A user sets a capillary cartridge, which will be described in detail later, in the thermostat unit 41, performs electrophoresis while keeping the capillary at a constant temperature in the thermostat unit 41, and performs detection with the irradiation detection unit 42. Further, the thermostat unit 41 is also provided with an electrode (anode) 44 for dropping to GND when a high voltage for electrophoresis is applied. The thermostat unit 41 has a mounting surface 50 for a capillary cartridge described later.

  As described above, the capillary cartridge is fixed to the thermostat unit 41. The electrophoresis medium container 28, the anode-side buffer solution container 29, the cathode-side buffer solution container 33, and the sample container 26 can be driven in the YZ axes by the autosampler unit 20, and only the sample container 26 is further driven in the X axis. I can do it. The electrophoresis medium container 28, the anode buffer solution container 29, the cathode buffer solution container 33, and the sample container 26 can be automatically connected to an arbitrary position by the movement of the autosampler unit 20 to the capillary of the fixed capillary cartridge. I can do it.

  FIG. 2 shows a diagram of the capillary electrophoresis apparatus shown in FIG. 1 as viewed from above. The anode-side buffer solution container 29 set on the sample tray 25 includes an anode-side washing tank 30, an anode-side electrophoresis buffer tank 31, and an anode-side sample introduction buffer tank 32. The cathode-side buffer solution container 33 includes a waste solution tank 34, a cathode-side washing tank 35, and a cathode-side electrophoresis buffer solution tank 36.

  The electrophoresis medium container 28, the anode buffer solution container 29, the cathode buffer solution container 33, and the sample container 26 are arranged in a positional relationship as shown in FIG. Accordingly, when the capillary cartridge in the thermostat unit 41 is connected to the capillary 02, the positional relationship between the anode side and the cathode side is "electrophoresis medium container 28-waste liquid tank 34", "anode cleaning tank 30-cathode side". The washing tank 35 ", the" anode-side electrophoresis buffer 31-cathode-side electrophoresis buffer 36 ", and the" anode-side sample introduction buffer 32-sample container 26 ".

  FIG. 3 is a cross-sectional view of the capillary electrophoresis apparatus shown in FIG. The electrophoresis medium container 28 is set on the sample tray 25. The liquid feeding mechanism 27 is arranged such that a plunger built in the liquid feeding mechanism 27 is below the electrophoresis medium container 28.

  In electrophoresis, the right side in FIG. 3 is the cathode side of the capillary 02, and the left side is the anode side. The autosampler unit 20 moves to the position of “anode-side electrophoresis buffer solution tank 31-cathode-side electrophoresis buffer solution tank 36” shown in FIG. 2, and a high voltage is applied to the capillary 02 on the electrode (cathode) 08 side. Then, electrophoresis is performed by flowing to GND at the electrode (anode) 44 via the cathode side buffer solution container 33 and the anode side buffer solution container 29. Note that the apparatus may have a structure in which the position of the sample tray 25 is fixed and the irradiation detection / constant temperature bath unit 40 is movable.

  FIG. 4 shows a schematic diagram of one configuration of the capillary cartridge in the present embodiment. The capillary cartridge 01 includes a capillary 02, a support body 03, a radiator 04, an electrode holder 05, a detection unit 06, a capillary head 07, an electrode (cathode) 08, and a handle 09 serving as a holding unit. Further, the electrode (cathode) 08 may have a structure directly fixed to the support body 03. 4, the capillary cartridge 01 is arranged from the near side in FIG. 4 in the order of a support 03 provided with a handle 09, a radiator 04, and a capillary 02.

  The capillary head 07 is an end of the capillary 02, and is an injection end or a discharge end that bundles and holds the capillaries 02 and fills the electrophoresis medium. In this embodiment, when the capillary cartridge 01 is attached to the electrophoresis apparatus, the capillary head 07 is connected to the container storing the electrophoresis medium, thereby functioning as an injection end. The capillary head 07 is set in a state of being bent in the electrophoresis apparatus.

  FIG. 5 is an exploded view of the capillary cartridge 01 in the present embodiment shown in FIG. The heat radiator 04 is attached to the support body 03 by the adhesiveness or tackiness of the heat radiator 04, or by chemical bonding or a physical attachment mechanism. In addition, the capillary 02 has an integral structure by attaching the electrode holder 05 and the detection unit 06 to the support body 03. The electrode holder 05 holds an electrode (cathode) 08 and is fixed to the support 03 by passing an electrode holder fixing pin 10 formed on the electrode holder 05 through the electrode holder fixing hole 11 of the support 03. It has become. Further, the support 03 is provided with a detection unit fixing frame 12 for fixing the detection unit 06. The detection unit 06 is fixed to the support 03 by being fitted into the detection unit fixing frame 12 formed on the support 03. You.

  The capillary 02 is a circular channel provided with a coating for maintaining light shielding and strength, and is, for example, a quartz glass tube having an inner diameter of about 50 μm and a polyimide coating. This tube is filled with an electrophoresis medium to provide an electrophoresis path for electrophoretically separating a sample. Since the capillary 02 and the heat radiator 04 are in close contact with each other, heat generated from the capillary 02 when a high voltage is applied can be released to the support 03 by the heat radiator 04, and the temperature inside the capillary 02 can be prevented from rising. it can.

The electrodes (cathodes) 08 are provided corresponding to the number of the capillaries 02, and by applying a voltage, a charged sample is introduced into the capillaries 02, and electrophoretic separation can be performed for each molecular size. The electrode (cathode) 08 is, for example, a stainless steel pipe having an inner diameter of about 0.1 to 0.5 mm, into which the capillary 02 is inserted.

  The detection unit 06 is located at an intermediate portion of the capillary 02, and the capillaries 02 are arranged in a plane with a certain accuracy. The detection unit 06 is a place where the fluorescence of the sample passing through the capillary 02 is detected, and it is necessary to align the position of the detection system of the apparatus with high accuracy.

  FIG. 6 shows an example of a detailed view of the attachment of the capillary cartridge 01 of the present embodiment. The upper part of the drawing shows the state before the attachment, and the lower part shows the state after the attachment to the thermostat unit 41. When the positioning pin 13 of the detection unit 06 is attached to the mounting surface 50 of the electrophoresis apparatus on the side of the thermostat unit 41 and is pushed through the positioning hole 14 of the support 03, the detection unit 06 is temporarily fixed by the clip 51. At the same time, the taper-shaped electrode holder positioning pin 15 on the thermostat unit 41 side of the mounting device automatically enters the electrode holder positioning hole 16 of the support body 03, so that the capillary cartridge 01 can be moved in one operation by the thermostat unit. 41 is temporarily fixed. Note that the electrode holder positioning pins 15 and the electrode holder positioning holes 16 may be mounted at opposite positions. That is, the electrode holder 05 and the support body 03 can be fixed by passing the electrode holder positioning pins provided on one side through the electrode holder positioning holes provided on the other side.

  FIG. 7 shows a configuration example of the vicinity of the capillary 02 in the capillary electrophoresis apparatus according to the present embodiment in which the risk of discharge is reduced. The heater assembly 60 is attached to the constant temperature bath base 67. In the same figure, for easy understanding, the heater assembly 60 is shown separated from the thermostatic bath base 67. Hereinafter, the same applies.

  The heater assembly 60 includes a heat insulating rubber 61, a resistance heater 62, a conductive member 63, and a heat radiating rubber 64 constituting a structure including an insulating member, and these are fixed to each other by a method such as adhesion, welding, or screwing. . In the present embodiment, the heat generated by the resistance heater 62 is transmitted to the capillary 02 of the capillary cartridge 01 through the conductive member 63 and the heat radiation rubber 64 to heat the capillary 02. Further, a heat insulating material 61 is attached to the constant temperature bath base 67 side of the heater assembly 60 so as not to dissipate the heat of the resistance heater 62.

  Since the heat radiation rubber 64 needs to efficiently transmit the heat generated from the resistance heater 62 to the capillary 02, it is desirable that the heat radiation property be excellent. Further, it is desirable that the material be soft so as not to damage the capillary 02 in contact.

  The temperature of the resistance heater 62 is controlled by a temperature sensor such as a thermistor attached to the heater assembly 60. The attachment position of the thermistor (not shown) may be any of the heat insulating material 61, the resistance heater 62, the conductive member 63, and the heat radiation rubber 64, but is preferably on the heat radiation rubber 64.

  A low-potential portion contacts the conductive member 63. The low potential portion is generally called ground or GND (ground), and has a virtual zero potential by being connected to the power supply of the device. In this embodiment, an earth plate 66 is attached to the thermostat base 67 as a low potential portion that comes into contact with the conductive member 63. This ground plate 66 is grounded to the conductive member 63 avoiding the surfaces of the heat insulating material 61 and the resistance heater 62. As the shape of the low potential portion, a shape such as a ground line or a frame GND via a frame of the device may be used instead of the ground plate.

FIG. 8 shows a structure in which chamfering processing 70 is performed as a specific example of the shape of the conductive member 63 in the present embodiment. The conductive member 63 is a member excellent in conductivity including at least a part of a metal. For example, a single metal plate such as aluminum, iron, brass, and stainless steel is one preferable example. Alternatively, a resin plate or an elastomer mixed with metal powder or metal filler may be used. Furthermore, a metal surface, a metal sheet, a metal thin film, or the like that is deposited on the resistance heater 62 or the heat radiation rubber 64 may be used.

  The conductive member 63 similarly has a zero potential by being grounded to the ground plate 66 having a zero potential as described above. Since the conductive member 63 has a zero potential, it has the effect of lowering the potential of the nearby components and the function of determining the point at which the potential falls to a portion to which high voltage is applied. But it is good. One of the preferable examples is a single-plate shape to realize space saving. However, in order to avoid electric field concentration, it is desirable to avoid sharp shapes as much as possible, and to reduce the risk of electric discharge by chamfering 70 at edges. The specific example of FIG. 8 is an example in which a plate shape is formed in accordance with the shape of the heater assembly 60 and the electric field concentration is avoided by performing the chamfering processing 70.

  FIG. 9 shows an example in which the conductive member 63 shown in FIG. 8 is subjected to an insulation treatment. It is desirable that the conductive member 63 be insulated so that discharge does not occur directly to the conductive member 63. For example, it is a preferable example that the entire conductive member 63 is wrapped with a polyimide sheet, an insulating elastomer, a resin, or the like.

  FIG. 9 shows a specific example in which the thickness of the insulating member is changed in proportion to the distance from the high-voltage portion, and a method for performing an optimal insulating process is performed. The upper part of the conductive member 63 is wound with one insulating material 80 because the distance from the high-voltage part is farthest, and the middle part is wound with two insulating materials 81 thicker than the upper part. The lowermost part, which is close to the high voltage part, is wound with three thickest insulating materials 82. Insulating materials typified by polyimide sheets are generally expensive, and thermal conductivity decreases as the thickness increases, so this configuration is lower in cost and heat than attaching an insulating material with a uniform thickness throughout. A function that suppresses a decrease in conductivity can be realized. Instead of changing the number of turns of the insulating material, a gradation may be given to the insulating performance and the thermal conductivity in one insulating material. It is needless to say that if the cost and the decrease in the thermal conductivity are within the allowable range, an insulating material having a uniform thickness can be attached to the whole. However, in any case, it is necessary to perform the insulation treatment in a form in which the conductive member 63 has a function of grounding the ground plate 66. In addition, the surface where the thermostatic bath base 67 and the conductive member 63 are in contact may be protruded so that a sufficient creepage distance can be obtained between the conductive member 63 and the conductive member 63.

  In the configuration of the present embodiment, when the electrophoresis is started by the capillary electrophoresis apparatus in which the conductive member 63 shown in FIGS. 8 and 9 is included in the thermostat base 67 of FIG. A high voltage is applied to the high voltage portion in the holder 05. Since the discharge phenomenon occurs due to the potential difference, the discharge occurs at this time to the ground plate 66 or the conductive member 63 having zero potential. However, in the configuration of the present embodiment, the conductive member 63 and the thermostatic bath base 67 are in contact at the lower side of the conductive member 63, and the thermostatic bath base 67 and the electrode holder 05 are in contact with each other so as to enclose the electrode plug 65.

  At this time, since the thermostatic bath base 67 and the electrode holder 05 are insulating members, the high-voltage portion and the low-voltage portion at zero potential are in contact with each other by a plurality of insulated structures. Then, the potential gradually decreases from the portion to which the high voltage is applied to the conductive member 63 having zero potential using the thermostat base 67 as a dielectric. The conductive member 63, which is grounded to the ground plate 66, which is a low potential portion, has a virtual zero potential of the device like the ground plate 66. In general, a high potential is generated in a portion where a high voltage is applied and in the vicinity thereof. However, since the potential of components located in the vicinity of the conductive member 63 and the conductive member 63 having zero potential decreases, the electrode plug 65 and the electrode holder In this configuration, no discharge occurs from the high-voltage part 05 to parts other than the conductive member 63.

Here, as the conductive member 63 is structurally larger, the potential of components near the conductive member 63 is also likely to decrease. For example, the fact that the area of the conductive member 63 is larger than the area of a member to which a high voltage is applied by, for example, a capillary electrode held by an electrode holder is one of the factors that increase the effect of suppressing discharge to a nearby part. .

  Embodiment 2 Embodiment 2 is another embodiment of the capillary electrophoresis apparatus in which the discharge risk is reduced even in a component configuration in which a creepage distance and a space distance cannot be sufficiently obtained.

  As shown in FIG. 10, the same components as those in the first embodiment shown in FIG. 7 are provided, but the order of the conductive surface and the resistance heater 62 included in the heater assembly 60 is different. That is, the conductive member 63 is arranged adjacent to the heat insulating material 61, and then the resistance heater 62 is arranged. This is because the conductive surface of the conductive member 63 and the conductive surface of the conductive member 63 are replaced with each other, thereby shortening the distance between the conductive surface of the conductive member 63 and the thermostatic bath base 67, so that the conductive surface of the conductive member 63 is smaller than when the resistance heater 62 is interposed. And the electric potential of the thermostatic bath base 67 are brought close to each other. With the configuration of the present embodiment, it is expected that the potentials of the thermostatic bath base 67 and the components in the vicinity thereof can be further reduced. Further, as in the first embodiment, the conductive member 63 is provided with an insulation measure so as to prevent direct discharge from occurring in the conductive member 63.

  As shown in the first embodiment and the second embodiment, the order of the components configured to improve the performance may be changed, and the shape may be changed accordingly.

  The third embodiment is an embodiment of a configuration in which a heat retention function is further provided in a capillary electrophoresis apparatus in which a discharge risk is reduced even in a component configuration in which a creepage distance and a space distance cannot be sufficiently obtained. That is, Example 3 is a capillary electrophoresis apparatus for analyzing a sample by electrophoresis using a capillary, and includes at least one heater for heating the capillary, an electrode holder for holding the capillary electrode and connected to the high-voltage section. Capillary electrophoresis in which a part is made of metal and has a conductive heat storage plate grounded to a low potential, and the electrode holder and the conductive heat storage plate are in contact with each other by a structure, and the structure is an insulating member. It is an Example of an apparatus.

  In the present embodiment shown in FIG. 11, a heat storage function is also provided by using a conductive heat storage plate 90 instead of the conductive member 63 in the embodiment shown in FIG. The conductive heat storage plate 90, which is a conductive member, is a member having excellent conductivity including at least a part of metal and having a large heat capacity. For example, a single metal plate made of aluminum, iron, brass, stainless steel, or the like having a thickness of about 1.0 mm to 10.0 mm is a preferable example in terms of conductivity and heat capacity. In addition, among resin plates and elastomers mixed with metal powder or metal filler, those having high heat capacity are preferable. As in the case of the conductive member 63 of the first embodiment, insulation measures are taken to prevent direct discharge from occurring in the conductive heat storage plate 90. Further, the structure between the conductive heat storage plate 90 and the electrode holder 05 is in contact with the heat radiation rubber 64 as a structure made of an insulating member, similarly to the first embodiment.

  In the configuration of the present embodiment using the conductive heat storage plate 90, for example, when the capillary cartridge 01 is replaced, an effect is obtained that the temperature does not easily drop even if the user opens and closes the thermostatic chamber door 43. This is because the conductive heat storage plate 90 as a conductive member has a function of sufficiently storing heat generated from the resistance heater 62 due to a high heat capacity, in addition to a function of lowering a discharge risk.

  The effect of the present embodiment, together with the actual verification results based on the configuration of the present embodiment, will be described with reference to FIGS.

  First, FIG. 13 is a graph showing one of the ideal states in which there is no floating metal around the electrode holder 05 which is a high voltage application part, and all the insulated structures in contact with the electrode holder 05 function as dielectrics. The horizontal axis indicates the distance and the vertical axis indicates the potential. The distance x at the position of the electrode holder 05 to which -20 kV is applied is set to zero. At this time, as shown in the upper part of the figure, the potential gradually drops from -20 kV to 0 kV, and no discharge occurs.

  The right side of FIG. 14 shows the result of an electrophoresis test performed by removing the conductive heat storage plate 90 from the configuration in the vicinity of the capillary in FIG. 11 of the present embodiment. As shown in the figure, while the applied voltage of the device was applied stepwise from 0 kV to −20 kV, both the current value of the device power supply and the capillary current value fluctuated greatly. A large discharge occurs around 18 kV from both the power supply and the capillary. This indicates that electric discharge occurs from the electrode holder 05, which is a high-voltage application unit, in a gap of about 10 mm formed due to the absence of the internal conductive heat storage plate 90.

  The left side of FIG. 14 shows an example in which the phenomenon that occurred at this time was predicted from the viewpoint of the potential and the electric field. The electric field is concentrated through the gap and breaks the pressure resistance of air, so that electric discharge occurs. At this time, the potential drops sharply.

  Next, on the right side of FIG. 15, a conductive heat storage plate 90 and an electrode holder 05 are provided, and in a state where a gap of 1 mm or less is provided between the insulated structure and the conductive heat storage plate 90, The results obtained when an electrophoresis test was performed are shown. Although an extreme current value fluctuation does not occur as compared with FIG. 14, a minute current value fluctuation intermittently occurs even in a low voltage environment, and a large current value increases when a -19 kV or -20 kV voltage is applied. Shaking is occurring.

  The left side of FIG. 15 is an example in which the phenomenon that occurred at this time is predicted from the viewpoint of the potential and the electric field. Since the conductive heat storage plate 90 has zero potential, the potential drops toward it, but no discharge occurs because it is insulated. Further, electric field concentration occurs in a minute gap of 1 mm or less, but does not lead to a large discharge phenomenon. However, since the gap is 1 mm or less, which is smaller than the example shown in FIG. 14, intermittent fluctuation of the current value occurs. In addition, when a high voltage of -19 kV or more is applied, discharge eventually occurs.

  Finally, the right side of FIG. 16 shows the results when an electrophoresis test was performed using the structure of this example. The gap provided in FIG. 15 is eliminated, and the conductive heat storage plate 90 and the electrode holder 05 are continuously in contact with one or a plurality of insulated structures without any gap. Fluctuation of the current value is hardly observed in both the device power supply and the capillary.

  The left side of FIG. 16 is an example in which the phenomenon that occurred at this time was predicted from the viewpoint of the potential and the electric field. Since the conductive heat storage plate 90 has zero potential, the potential drops toward it, but no discharge occurs because it is insulated. Further, since there is no gap, the structure, which is an insulating member, becomes a dielectric even after passing the conductive heat storage plate 90, and the potential gradually decreases.

  Fourth Embodiment A fourth embodiment is another embodiment in which the capillary electrophoresis apparatus in which the risk of discharge is reduced is further provided with a heat retaining function even in a component configuration in which a creepage distance and a space distance cannot be sufficiently obtained. That is, Example 4 is a capillary electrophoresis apparatus, in which a heater for heating a capillary, a non-conductive heat storage plate, an electrode holder that holds a capillary electrode and is connected to a high-voltage part, and at least a part of which is made of metal, This is an embodiment of an electrophoresis apparatus having a configuration in which a conductive member grounded to a low potential is provided, and the electrode holder and the conductive member are in contact with each other by a structure serving as an insulating member.

As shown in FIG. 12, of the structure shown in FIG. 11, a conductive heat storage plate 9 having a heat storage function is provided.
0 is a non-conductive heat storage plate 100, and a conductive member 63 is attached as a conductive surface. As the non-conductive heat storage plate 100, using one non-conductive heat storage plate such as alumina or a glass plate having a thickness of, for example, about 1.0 mm to 10.0 mm is one of preferable examples from the viewpoint of heat capacity. is there. As the conductive member 63 to be attached to the non-conductive heat storage plate 100, one metal plate such as aluminum, iron, brass, and stainless steel mentioned in the previous embodiment, or a resin plate mixed with metal powder or metal filler , An elastomer, a metal surface or metal sheet to be deposited, a metal thin film, and the like. Also in the present embodiment, it is desirable that the conductive member 63 be insulated so that discharge does not occur directly in the conductive member 63.

  In FIG. 12, the conductive surface of the conductive member 63 is sandwiched between the resistance heater 62 and the non-conductive heat storage plate 100. However, the non-conductive heater combining the resistance heater 62 and the conductive heat storage plate 90 is used. For example, it is desirable that the above-mentioned conductive member 63 is adhered to what is generally called a ceramic heater or a glass heater, and is insulated so as not to cause direct discharge.

  According to the present invention described in detail above, a conductive member that is at least partially made of metal and is grounded to a low potential generally called a ground or a ground can be considered to have a substantially zero potential. Since the insulating member functions as a dielectric, the potential difference can be gradually reduced even if there is a potential difference in a component that is in contact with the conductive member by the insulating member.

  The electrode holder that holds the capillary electrode has a high potential to connect to the high voltage section. Therefore, when the electrode holder and the conductive member are in contact with each other by the insulating member, the potential can be gradually decreased even when a high voltage is applied to the capillary via the electrode.

  For example, if there is a sufficient creepage distance or space distance between the electrode holder and the low-potential structure, no discharge occurs during this time. If a sufficient distance cannot be secured for miniaturization, it is conceivable to insert an insulating member. However, if there is a gap between the insulating member and the electrode holder or the low-potential body, discharge occurs in this gap. This uses an insulating member as a dielectric, and the potential gradient gradually drops in this dielectric, but the potential gradient between the insulating member and the air gap becomes steeper than when nothing is inserted, so discharge tends to occur. It is because it becomes. Therefore, it is desirable that the electrode holder and the conductive member are continuously contacted by a single or a plurality of insulating members without any gap.

  In addition, if the structure is not an insulating member, it does not have a property as a dielectric, and thus does not have a function of gradually reducing the potential difference. Therefore, the structure is composed of an insulating member composed of a single layer or a plurality of layers.

  Furthermore, for example, when the conductive member is a simple metal plate or a vapor-deposited metal surface and is not in contact with the ground or the ground, it is a metal floating in the air, so that the potential difference does not drop and is only kept constant. . Further, if the conductive member does not exist, the destination where the high potential of the high voltage portion falls is not determined. Then, the discharge or the discharge location changes depending on the surface condition of the nearby component or a change in the distance due to driving. From these facts, it is difficult to take countermeasures against discharge unless at least a part of the present invention is made of metal and there is no conductive member grounded to a low potential and a surface containing a metal grounded to a low potential.

  Note that the present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiments have been described in detail for better understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of one embodiment can be added to the configuration of another embodiment. Also, for a part of the configuration of each embodiment, it is possible to add, delete, or replace another configuration.

01: Capillary cartridge, 02: Capillary, 03: Support, 04: Heat radiator, 05: Electrode holder, 06: Detector, 07: Capillary head, 08: Electrode (cathode), 09: Handle, 10: Electrode holder fixed Pin, 11: Electrode holder fixing hole, 12: Detection unit fixing frame, 13: Detection unit positioning pin, 14: Positioning hole, 15: Electrode holder positioning pin, 16: Electrode holder positioning hole, 20: Autosampler unit, 21: Sampler base, 22: X-axis drive, 23: Y-axis drive, 24: Z-axis drive, 25: sample tray, 26: sample container, 27: liquid transfer mechanism, 28: electrophoresis medium container, 29: anode side Buffer solution container, 30: anode side washing tank, 31: anode side electrophoresis buffer solution tank, 32: anode side sample introduction buffer solution tank, 33: cathode side buffer solution container, 34: Liquid tank, 35: Cathode side washing tank, 36: Cathode side electrophoresis buffer tank, 40: Irradiation detection / constant temperature bath unit, 41: Constant temperature bath unit, 42: Irradiation detection unit, 43: Constant temperature bath door, 44: Electrode (anode), 50: mounting surface, 51: clip, 60: heater assembly, 61: heat insulating material, 62: resistance heater, 63: conductive member, 64: heat radiation rubber, 65: electrode plug, 66: ground plate, 67: constant temperature bath base, 70: chamfering, 80: one insulating material, 81: two insulating materials, 82: three insulating materials, 90: conductive heat storage plate, 100: non-conductive heat storage plate

Claims (9)

In an electrophoresis apparatus having a capillary and analyzing a sample by electrophoresis,
A heater as a heat source;
And a conductive member at least partially made of metal,
The electrophoretic device according to claim 1, wherein the conductive member is in contact with a ground portion and is insulated. The electrophoretic device according to claim 1,
An electrophoretic device comprising a structure made of an insulating member between the conductive member and the capillary. The electrophoretic device according to claim 2,
An electrophoresis apparatus, wherein the structure is a heat radiation rubber. The electrophoresis apparatus according to any one of claims 1 to 3,
An electrophoretic device, wherein the conductive member is chamfered. The electrophoretic device according to claim 4,
A high voltage portion to which the electrode plug is connected,
The electrophoresis apparatus according to claim 1, wherein the insulating treatment of the conductive member is performed stepwise according to a distance from a high voltage part. The electrophoresis apparatus according to any one of claims 1 to 4,
The heater and the thermostatic bath base to which the conductive member is attached and made of an insulating member,
A high voltage portion to which the electrode plug is connected,
The electrophoresis apparatus, wherein the thermostat base is located between the conductive member and the high-voltage section. The electrophoresis apparatus according to any one of claims 1 to 4,
A high voltage portion to which the electrode plug is connected,
An electrophoretic device, wherein the conductive member and the high voltage portion are in contact with each other via a structure made of an insulating member, which is composed of a single layer or a plurality of layers. The electrophoretic device according to claim 1,
The heater has a constant temperature bath base to which the conductive member is attached,
An electrophoresis apparatus comprising a heat insulating material located between the constant temperature bath base and the conductive member and in contact with the constant temperature bath base. The electrophoretic device according to claim 1,
The electrophoretic device according to claim 1, wherein the conductive member is a metal plate having a thickness of 1.0 to 10 mm.

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