High-voltage electric power supply device for microchip electrophoresis device, and microchip electrophoresis device

Abstract

This high-voltage electric power supply device capable of supplying a high voltage to a microchip electrophoresis device comprises a substrate, a plurality of high-voltage generation circuits that are arranged on an upper surface (first surface) of the substrate, and a plate-form shield member that is disposed on the first-surface side of the substrate. Each high-voltage generation circuit has a transformer, a plurality of the high-voltage generation circuits are arranged between the first surface of the substrate and the shield member 2, and the plate surface of the shield member is disposed parallel to the coil axis of each transformer.

Description

High-voltage power supply for microchip electrophoresis device and microchip electrophoresis device

[0001] The present invention relates to a power supply device that supplies a high voltage to a microchip electrophoresis device, and to a microchip electrophoresis device equipped with the power supply device.

[0002] A method for analyzing samples using microchip electrophoresis is known. In a microchip electrophoresis device, a sample solution is injected into a minute channel formed on a microchip. Then, electrophoresis occurs when a high voltage (several kV or tens of kV) is applied to both ends of the channel into which the sample solution has been injected. Electrophoresis separates components (charged substances) contained in the sample solution due to differences in mobility based on their size. The components separated by electrophoresis are detected by a detector. Microchip electrophoresis can be used to analyze substances such as DNA and proteins.

[0003] Patent Document 1 below discloses a microchip electrophoresis device.

[0004] JP 2023-105739 A

[0005] The microchip electrophoresis device includes a high-voltage power supply for applying a high voltage to terminals provided on the microchip. Since a plurality of terminals are provided in the flow channel formed on the microchip, the high-voltage power supply is provided with a plurality of high-voltage generating circuits corresponding to the plurality of terminals.

[0006] Each of the multiple high-voltage generation circuits has a high-voltage output terminal. When a single high-voltage generation circuit outputs a high voltage, even if the output voltage stability and response speed are within the specification range, when multiple high-voltage generation circuits output a high voltage from their respective output terminals, the ripple in the output voltage becomes large. This is because adjacently arranged high-voltage generation circuits are affected by noise from each other. In microchip electrophoresis, analysis is performed while a high voltage is applied to multiple electrode terminals on the microchip, so the ripple in the voltage output from the high-voltage generation circuit becomes large. If the ripple in the output voltage of the high-voltage generation circuit becomes large, the speed of substances moving by electrophoresis becomes unstable, which reduces the accuracy of sample separation.

[0007] Specifically, the transformers used in high-voltage generating circuits emit inductive noise when generating high voltage, which affects adjacent high-voltage generating circuits. While it may be possible to reduce the impact of noise by increasing the distance between the circuits, there are also restrictions imposed by the size of the device, making it difficult to ensure sufficient distance to reduce the impact of inductive noise.

[0008] An object of the present invention is to reduce the influence of noise from adjacent high voltage generating circuits in a power supply device that supplies high voltage to a microchip electrophoresis device.

[0009] A high-voltage power supply device for a microchip electrophoresis device according to one aspect of the present invention is a high-voltage power supply device capable of supplying a high voltage to a microchip electrophoresis device, and includes a substrate, a plurality of high-voltage generation circuits arranged on a first surface of the substrate, and a plate-shaped shield member arranged on the first surface side of the substrate. Each high-voltage generation circuit has a transformer, and the plurality of high-voltage generation circuits are arranged between the first surface of the substrate and the shield member, and the plate surface of the shield member is arranged parallel to the coil axis of each transformer.

[0010] The present invention is also directed to a microchip electrophoresis device equipped with the above-mentioned high-voltage power supply device.

[0011] According to the present invention, in a power supply device that supplies a high voltage to a microchip electrophoresis device, it is possible to reduce the influence of noise from adjacent high voltage generating circuits.

[0012] Fig. 1 is an overall view of a microchip electrophoresis device according to this embodiment. Fig. 2 is a diagram showing the internal structure of the microchip. Fig. 3 is a plan view showing a high-voltage power supply device according to this embodiment. Fig. 4 is a side cross-sectional view of the high-voltage power supply device shown in Fig. 3 taken along line IV-IV.

[0013] Next, the configurations of a high-voltage power supply device 1 for a microchip electrophoresis device and a microchip electrophoresis device ME according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0014] (1) Overall Configuration of Microchip Electrophoresis Apparatus Fig. 1 is an overall view showing a microchip electrophoresis apparatus ME according to this embodiment. The microchip electrophoresis apparatus ME includes a high-voltage power supply device 1, a supply unit 6, a microchip 7, a detector 8, and a control unit 9. The high-voltage power supply device 1 is an example of a high-voltage power supply device for a microchip electrophoresis apparatus according to the present invention.

[0015] The high-voltage power supply 1 applies a high voltage to multiple electrode terminals provided on the microchip 7. The supply unit 6 supplies the sample solution to be analyzed, a separation buffer, a cleaning solution, etc. to the microchip 7. The microchip 7 holds the sample solution to be analyzed. Components (charged substances) contained in the sample solution held in the microchip 7 migrate and separate by electrophoresis. The detector 8 detects the components that have migrated and separated by electrophoresis in the microchip 7. The control unit 9 controls each functional unit of the microchip electrophoresis apparatus ME, including the high-voltage power supply 1, the supply unit 6, and the detector 8.

[0016] (2) Microchip Configuration The configuration of the microchip 7 will be described with reference to Figures 1 and 2. As shown in Figure 1, the microchip 7 is composed of a substantially rectangular plate-shaped member. Four electrode terminals 71a, 71b, 71c, and 71d are arranged on the plate surface of the microchip 7. The four electrode terminals 71a to 71d are each connected to the high-voltage power supply device 1. This allows a high voltage to be applied to each of the electrode terminals 71a to 71d by the high-voltage power supply device 1.

[0017] Fig. 2 is a diagram showing the internal structure of the microchip 7. As shown in Fig. 2, two flow paths (capillaries) 73 and 74 for holding sample solutions are formed inside the microchip 7. The flow paths 73 and 74 intersect with each other to form a cross-shaped flow path as a whole. The flow path 73 is used to guide the sample solution to be analyzed to the flow path 74. The flow path 74 is used as a separation flow path that separates the sample solution to be analyzed by electrophoresis.

[0018] Reservoirs 75a, 75b are provided at both ends of flow channel 73. Reservoirs 75c, 75d are provided at both ends of flow channel 74. Reservoirs 75a, 75b, 75c, and 75d are spaces for supplying and aspirating separation buffer and sample solution. Reservoirs 75a, 75b, 75c, and 75d have cylindrical spaces extending perpendicular to the plate surface of microchip 7. Flow channels 73, 74 and reservoirs 75a to 75d configured as described above are formed inside microchip 7.

[0019] 1, electrode terminals 71a and 71b are respectively arranged in reservoirs 75a and 75b provided at both ends of flow channel 73. That is, electrode terminals 71a and 71b are respectively arranged at the ends of reservoirs 75a and 75b extending in a direction perpendicular to the plate surface of microchip 7. Furthermore, electrode terminals 71c and 71d are respectively arranged in reservoirs 75c and 75d provided at both ends of flow channel 74, as shown in FIG. 1. Similarly, electrode terminals 71c and 71d are respectively arranged at the ends of reservoirs 75c and 75d extending in a direction perpendicular to the plate surface of microchip 7.

[0020] In the microchip electrophoresis apparatus ME, electrophoresis is performed by applying a voltage from a high-voltage power supply 1 to electrode terminals 71a to 71d provided in the flow channels 73 and 74. The voltage applied to the electrode terminals 71a to 71d is controlled by a control unit 9.

[0021] The analysis of a sample using the microchip electrophoresis device ME is performed as follows. First, the supply unit 6 fills the entire interior of the channels 73 and 74 with a separation buffer. The separation buffer, which also serves as a "separation medium," contains, for example, a pH buffer and a water-soluble polymer (such as a cellulose-based polymer). Next, the supply unit 6 supplies a sample solution to be analyzed to the reservoir 75a of the channel 73. A fluorescent dye is mixed into the sample solution. Then, the high-voltage power supply 1 applies a predetermined voltage to the electrode terminals 71a to 71d, creating an electric field gradient within the channels 73 and 74. This causes the sample solution to move within the channel 73 to the position where the channels 73 and 74 intersect. Then, the magnitude of the voltage applied to each of the electrode terminals 71a to 71d by the high-voltage power supply 1 is changed, causing the sample solution to move toward the electrode terminal 71d (reservoir 75d) within the channel 74 while being separated by electrophoresis. For example, when the sample is a gene, the gene has a negative charge and therefore moves toward the anode when an electric field is applied.

[0022] In an analysis process using electrophoresis, components contained in a sample solution move within the flow channel 74 at different speeds depending on their size. For example, the migration speed of a gene is inversely proportional to the radius of the gene. This makes it possible to identify the size of a gene from the applied voltage value and arrival time. In the microchip electrophoresis apparatus ME, the components that arrive in order at the detection position 76 within the flow channel 74 are detected by the detector 8. In this way, the microchip electrophoresis apparatus ME detects the components contained in the sample solution according to the degree of separation (degree of migration).

[0023] The detector 8 detects the fluorescence of components separated by electrophoresis, for example. The detector 8 has an LED (light-emitting diode) that irradiates a detection position 76 of the flow path 74 with excitation light. The excitation light from the LED irradiates each component moving through the flow path 74 while being separated by electrophoresis, thereby exciting the component and causing it to emit fluorescence. The detector 8 detects the components separated by electrophoresis by measuring this fluorescence with a photomultiplier tube, for example, via an optical fiber and a filter member.

[0024] (3) Configuration of the High-Voltage Power Supply Device Next, the configuration of the high-voltage power supply device 1 according to this embodiment will be described with reference to Figures 3 and 4. Figure 3 is a plan view showing the high-voltage power supply device 1 according to this embodiment. Figure 4 is a side cross-sectional view of the high-voltage power supply device 1 shown in Figure 3 taken along line IV-IV. Although there is no particular vertical direction or the like in the high-voltage power supply device 1, for convenience in the following description, the XY plane in Figures 3 and 4 will be the horizontal direction of the high-voltage power supply device 1, and the Z direction will be the upward direction of the high-voltage power supply device 1.

[0025] As shown in Figures 3 and 4, four high-voltage generation circuits 11 are arranged on an upper surface 10U of a substrate 10 of the high-voltage power supply device 1. The upper surface 10U of the substrate 10 is an example of the first surface of the present invention. The substrate 10 is arranged parallel to the XY plane. Therefore, the upper surface 10U (first surface) of the substrate 10 is also parallel to the XY plane. Each of the four high-voltage generation circuits 11 has a transformer 12. The four high-voltage generation circuits 11 correspond to the four electrode terminals 71a to 71d of the microchip 7 described above. The control unit 9 individually controls the four high-voltage generation circuits 11, thereby applying a high voltage to the four electrode terminals 71a to 71d.

[0026] An input terminal 17 and an output terminal 18 are provided on the substrate 10 of the high-voltage power supply device 1. Power input from the input terminal 17 is converted into voltage by the transformer 12 of the high-voltage generating circuit 11 and then output from the output terminal 18. The output terminal 18 is connected via an output line to the electrode terminals 71a to 71d of the microchip 7 shown in FIG.

[0027] As shown in Fig. 3, the high-voltage power supply device 1 is provided with two spacers 15. Holes for providing the spacers 15 are arranged in two locations on the substrate 10. As shown in Fig. 4, the spacers 15 are cylindrical members, and the two spacers 15 support the shielding member 2. The shielding member 2 is a rectangular plate in a plan view. In this embodiment, the shielding member 2 is made of a copper member. The two spacers 15 are made of conductive members, and the lower ends of the spacers 15 are connected to GND via conductive members formed on the substrate 10.

[0028] In this embodiment, the substrate 10 and the shielding member 2 are arranged in parallel, and therefore the shielding member 2 is also parallel to the XY plane. In other words, the upper surface (first surface) 10U of the substrate 10 and the plate surface of the shielding member 2 are arranged in parallel. The length of the shielding member 2 in the Y direction is approximately the same as the length of the substrate 10 in the Y direction, and the shielding member 2 covers the entire substrate 10 in the Y direction. In contrast, the length of the shielding member 2 in the X direction is shorter than the length of the substrate 10 in the X direction, and the shielding member 2 is long enough to cover the transformers 12 in the X direction. As a result, the shielding member 2 is arranged to overlap with the four transformers 12 in a plan view.

[0029] The direction D shown in FIG. 3 indicates the axial direction of the transformer 12. That is, the coil of the transformer 12 is wound around its axis, with the direction D as its center. In this embodiment, the direction D coincides with the Y direction. Therefore, the axial direction D of the transformer 12 is parallel to the upper surface 10U of the substrate 10 and the plate surface of the shielding member 2. In this embodiment, the axial directions of all four transformers 12 are in the direction D. That is, the axial directions of all four transformers 12 are in the Y direction.

[0030] As described above, in the high-voltage power supply device 1 of the present embodiment, the shield member 2 is provided above the transformers 12, thereby reducing the ripple in the voltage output from each high-voltage generation circuit 11. This is because a portion of the induced noise radiated from the transformers 12 is converted into energy and consumed inside the shield member 2. In particular, in this embodiment, multiple transformers 12 are disposed between the upper surface (first surface) 10U of the substrate 10 and the shield member 2, and the plate surface of the shield member 2 is disposed parallel to the coil axis of each transformer 12. This effectively reduces the mutual influence of noise between the high-voltage generation circuits 11. In other words, the induced noise reaching each other between adjacent high-voltage generation circuits 11 is reduced, and the ripple in the output voltage can be reduced, similar to when a single high-voltage generation circuit 11 outputs a high voltage from a single output terminal.

[0031] Furthermore, in the above embodiment, the coil axes of the transformers 12 are all arranged along direction D (the common first direction), which more effectively reduces mutually reaching induced noise between adjacent high-voltage generation circuits 11. Furthermore, when viewed from a direction perpendicular to the top surface (first surface) 10U of the substrate 10, the shielding member 2 and all four transformers 12 overlap. In other words, the shielding member 2 covers the entire four transformers 12 in a plan view, so that induced noise radiated from the transformers 12 is effectively consumed by the shielding member 2.

[0032] In addition, in this embodiment, the shielding member 2 is connected to the GND of the substrate 10 via the spacer 15, so that the energy of the induced noise radiated from the transformer 12 flows from the shielding member 2 to the GND via the spacer 15.

[0033] (4) Other Embodiments In the above embodiment, a microchip electrophoresis device ME including one set of a microchip 7 and a high-voltage power supply device 1 has been described as an example. The present invention is similarly applicable to a case where the microchip electrophoresis device ME includes a plurality of microchips 7. When the microchip electrophoresis device ME includes a plurality of microchips 7, a plurality of high-voltage power supply devices 1 are provided corresponding to the plurality of microchips 7. By having the plurality of high-voltage power supply devices 1 include the configuration described in the above embodiment, the high-voltage generation circuit 11 included in each high-voltage power supply device 1 can supply a voltage with small ripple to each microchip 7.

[0034] As described in the above embodiment, the shielding member 2 is made of a conductive material such as copper to direct the energy of induced noise to the GND of the substrate 10. Therefore, for example, the shielding member 2 may be made using part of the substrate material used to manufacture the substrate 10. This allows for the use of part of the waste material generated when manufacturing the substrate 10, which also contributes to cost reduction.

[0035] In the above embodiment, the Y-direction length of the shielding member 2 has been described as being the same as the Y-direction length of the substrate 10. The Y-direction length of the shielding member 2 is not limited to this example, and may be shorter or longer than the Y-direction length of the substrate 10. However, it is desirable that the Y-direction length of the shielding member 2 be long enough to overlap all of the transformers 12 when viewed from a direction perpendicular to the top surface 10U of the substrate 10.

[0036] (5) Aspects It will be understood by those skilled in the art that the exemplary embodiments described above are specific examples of the following aspects.

[0037] (Item 1) A high-voltage power supply device for a microchip electrophoresis device according to one aspect of the present invention is a high-voltage power supply device capable of supplying a high voltage to a microchip electrophoresis device, and comprises: a substrate; a plurality of high-voltage generation circuits arranged on a first surface of the substrate; and a plate-shaped shielding member arranged on the first surface side of the substrate, each high-voltage generation circuit having a transformer, and the plurality of high-voltage generation circuits are arranged between the first surface of the substrate and the shielding member, and the plate surface of the shielding member is arranged parallel to the coil axis of each transformer.

[0038] In a power supply device that supplies a high voltage to a microchip electrophoresis device, the influence of noise on a high voltage generating circuit can be reduced.

[0039] (Item 2) In the high-voltage power supply device for a microchip electrophoresis device according to item 1, the coil axes of the transformers may be arranged along a common first direction.

[0040] The influence of noise on the high voltage generating circuit can be effectively reduced.

[0041] (Item 3) In the high-voltage power supply device for a microchip electrophoresis device according to item 1, the coil axis of each transformer may be arranged parallel to the first surface.

[0042] The substrate and the shielding member are arranged in parallel, which effectively reduces the influence of noise on the high-voltage generating circuit.

[0043] (4) In the high-voltage power supply device for a microchip electrophoresis device according to the first aspect, the shielding member and each transformer may overlap when viewed from a direction perpendicular to the first surface.

[0044] Since each transformer is covered with a shielding member, the influence of noise on the high voltage generating circuit can be effectively reduced.

[0045] (Item 5) In the high-voltage power supply device for a microchip electrophoresis device according to item 1, the shielding member may be connected to the GND of the substrate via a spacer.

[0046] The energy of the noise received by the shielding member can be released to the substrate side.

[0047] (Item 6) In the high-voltage power supply device for a microchip electrophoresis device described in Item 1, each high-voltage generation circuit may be used to supply a high voltage to any one of a plurality of electrode terminals provided at an end of a flow channel provided in the microchip electrophoresis device.

[0048] The ripple in the voltage supplied to each electrode terminal of the microchip is reduced, improving analytical accuracy.

[0049] (Item 7) In the high-voltage power supply device for a microchip electrophoresis device according to item 1, the shielding member may contain copper.

[0050] It can effectively consume the induction noise generated by the transformer.

[0051] (Item 8) In the high-voltage power supply device for a microchip electrophoresis device according to item 1, the shielding member may include the same material as the substrate.

[0052] It is possible to effectively utilize waste materials generated during the manufacture of substrates.

[0053] (Item 9) A microchip electrophoresis device according to another aspect of the present invention includes the high-voltage power supply device for a microchip electrophoresis device according to any one of items 1 to 8.

[0054] It is possible to provide a microchip electrophoresis device with high analytical accuracy.

Claims

1. A high-voltage power supply device for a microchip electrophoresis device capable of supplying a high voltage to a microchip electrophoresis device, comprising: a substrate; a plurality of high-voltage generation circuits arranged on a first surface of the substrate; and a plate-shaped shielding member arranged on the first surface side of the substrate, each high-voltage generation circuit having a transformer, the plurality of high-voltage generation circuits being arranged between the first surface of the substrate and the shielding member, and the plate surface of the shielding member being arranged parallel to the coil axis of each transformer.

2. A high-voltage power supply device for a microchip electrophoresis device according to claim 1, wherein the coil axes of the transformers are arranged along a common first direction.

3. A high-voltage power supply device for a microchip electrophoresis device according to claim 1, wherein the coil axis of each transformer is disposed parallel to said first plane.

4. A high-voltage power supply device for a microchip electrophoresis device according to claim 1, wherein said shielding member and each transformer overlap when viewed in a direction perpendicular to said first surface.

5. The high-voltage power supply device for a microchip electrophoresis device according to claim 1, wherein said shielding member is connected to the GND of said substrate via a spacer.

6. A high-voltage power supply device for a microchip electrophoresis device as described in claim 1, wherein each high-voltage generating circuit is used to supply a high voltage to one of a plurality of electrode terminals provided at the end of a flow path provided in the microchip electrophoresis device.

7. The high voltage power supply device for a microchip electrophoresis apparatus according to claim 1, wherein said shielding member comprises copper.

8. The high voltage power supply device for a microchip electrophoresis device according to claim 1, wherein said shielding member comprises the same material as said substrate.

9. A microchip electrophoresis device comprising the high-voltage power supply device for a microchip electrophoresis device according to any one of claims 1 to 8.

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