Electrophoretic device and polymer pouch cover used for same

Abstract

Provided is a capillary electrophoresis device for filling a capillary with a polymer, in which bubbles are prevented from entering the capillary at the time of polymer suction.　This electrophoresis device comprises: a capillary filled with a polymer; a pump for pumping the polymer into the capillary to fill in the capillary; a polymer pouch inside which the polymer is stored; and a polymer pouch cover for pressing the polymer pouch from the outside, the polymer pouch cover having a convex wall for forming a pseudo bubble flow path inside the polymer pouch.

Description

Electrophoresis device and polymer pouch cover used therein

[0001] The present invention relates to an electrophoresis apparatus for analyzing gene sequences, and more particularly to an electrophoresis apparatus in which a polymer serving as an electrophoresis medium is supplied to the electrophoresis apparatus in a pouch container, and to a polymer pouch cover used therein.

[0002] The scope of application of DNA analysis is rapidly expanding from research to clinical fields such as hospitals. One method of DNA analysis involves separating DNA fragments by electrophoresis, which is used in criminal investigations, determining blood relationships, and diagnosing diseases. In recent years, the mainstream method involves filling a capillary with a polymer, which serves as an electrophoresis medium, using a pump unit, and electrophoresing the DNA fragments to be analyzed onto the polymer. Patent Document 1 discloses a sealed container made of a flexible material that contains the polymer, preventing alteration and deterioration of the contents of the container due to contact with air. Hereinafter, the electrophoresis apparatus will also be referred to as a capillary electrophoresis apparatus.

[0003] JP 2009-31310 A

[0004] In a capillary electrophoresis apparatus, a polymer pouch containing a polymer as an electrophoresis medium is attached to a suction tube connected to a pump for sucking the polymer before use.

[0005] There is a possibility that air bubbles may exist in the polymer contained in the polymer pouch. If these air bubbles enter the capillary from the suction tube, discharge may occur from the air bubbles due to the application of high voltage during electrophoresis, and in the worst case scenario, the capillary may be damaged. Therefore, it is desirable to prevent air bubbles from entering the capillary as much as possible.

[0006] Conventionally, the prevention of air bubble contamination has been achieved by the user visually checking for the presence of air bubbles in the pump flow path. If air bubbles remain in the flow path, they are discharged together with the polymer newly sucked from the polymer pouch. In this case, the polymer discharged together with the air bubbles is wasted. Since polymer is expensive, it is undesirable for the user to have polymer discharged unnecessarily.

[0007] An object of the present invention is to provide a capillary electrophoresis apparatus in which a polymer is filled into a capillary, in which air bubbles are less likely to get mixed into the capillary when the polymer is sucked.

[0008] The present invention has the following configurations to achieve the above object.

[0009] That is, the electrophoresis device of the present invention is an electrophoresis device comprising a capillary filled with a polymer, a polymer pouch that contains the polymer, and a pump that transfers the polymer from the polymer pouch to the capillary, and is characterized in that the electrophoresis device comprises a polymer pouch cover that holds the polymer pouch from the outside, and the polymer pouch cover has a pressing portion for forming a bubble-blocking path inside the polymer pouch by pressing the polymer pouch.

[0010] According to the present invention, it is possible to provide a capillary electrophoresis apparatus in which a polymer is filled into a capillary, in which air bubbles are less likely to get mixed into the capillary when the polymer is sucked.

[0011] FIG. 1 is a diagram illustrating an example of a capillary electrophoresis device according to the present invention; FIG. 2 is a diagram illustrating a flow of capillary electrophoresis measurement using a capillary electrophoresis device according to the present invention; FIG. 3 is an explanatory diagram illustrating a method of filling capillaries with a polymer in a capillary electrophoresis device according to the present invention; FIG. 4 is an explanatory diagram illustrating a method of filling capillaries with a polymer in a capillary electrophoresis device according to the present invention; FIG. 5 is an explanatory diagram illustrating a method of filling capillaries with a polymer in a capillary electrophoresis device according to the present invention; FIG. 6 is a diagram illustrating an example of a polymer container for a capillary electrophoresis device according to the present invention; FIG. 7 is a diagram illustrating the structure of a pouch cover of Example 1, which is a first embodiment of a pouch cover for a polymer in a capillary electrophoresis device; FIG. 8 is a diagram illustrating the configuration of Example 1, which is a first embodiment of a pouch cover for a polymer in a capillary electrophoresis device according to the present invention; FIG. 9 is a diagram viewed from a cross-sectional direction of the pouch cover in Example 1; FIG. 10 is a diagram illustrating shape variations of a pressing portion of the present invention; FIG. 11 is a diagram illustrating the three-dimensional shape of a pressing portion of the present invention; FIG. 12 is a diagram illustrating another example of the shape of a pressing portion of the present invention; FIG. 13 is a diagram illustrating the structure of a pouch cover of Example 2, which is a second embodiment of a pouch cover for a polymer in a capillary electrophoresis device according to the present invention. Fig. 1 is a diagram showing the configuration of a polymer pouch. Fig. 2 is a diagram showing a state in which a pouch cover is attached to a polymer pouch in Example 2. Fig. 3 is a diagram showing a state in which the position of an air bubble in the polymer pouch is fixed by the pouch cover in Example 2. Fig. 4 is a diagram showing the configuration of Example 3, which is a third embodiment of a polymer pouch cover for a capillary electrophoresis device according to the present invention. Fig. 5 is a diagram showing a state in which the pouch cover in Example 3 fixes an air bubble above the suction port.

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description shows specific examples of the contents of the present invention, and the present invention is not limited to these descriptions. Various changes and modifications can be made by those skilled in the art within the scope of the technical ideas disclosed in this specification. Furthermore, in all drawings used to explain the present invention, parts having the same function are designated by the same reference numerals, and repeated explanations thereof may be omitted.

[0013] 1 shows an example of the configuration of a capillary electrophoresis apparatus according to the present invention. The capillary electrophoresis apparatus of this example comprises a pump unit 10, an autosampler unit 20, an irradiation / detection unit 30, a high-voltage power supply unit 40, and a thermostatic bath unit 50.

[0014] The pump unit 10 includes a syringe 101, a polymer block 102, a check valve 104, a flow path switching valve 106, a polymer bottle 108, and a buffer container 109, and fills the capillaries with a separation medium such as a polymer. The buffer container 109 is provided with an anode electrode 402. The operation of the pump unit will be described in detail later.

[0015] A tube 111 attached to a capillary head 112 at the tip of the capillary array 110 is connected to the polymer block 102 , and a capillary sample introduction end side electrode 401 is provided at the lower end of the capillary array 110 .

[0016] The autosampler unit 20 has an autosampler 203 that transports a sample container 201 into which a sample is dispensed, a buffer reservoir 202 that contains a buffer solution containing dissolved electrolytes, or a container containing cleaning water for cleaning the capillary tip or a container containing waste liquid to or from the capillary sample introduction end 204.

[0017] The irradiation / detection unit 30 has a light source such as a laser or LED that irradiates the capillary detection section 301 with excitation light 302, and a signal detection mechanism 303 that detects fluorescence from the capillary detection section 301. The high-voltage power supply unit 40 has a high-voltage power supply 403 that applies a high voltage between the capillary sample introduction end side electrode 401 and the anode side electrode 402. The thermostatic bath unit 50 has a thermostatic bath 501 that houses the capillary array 110.

[0018] The operation of the capillary electrophoresis apparatus according to the present invention will be described with reference to Figure 2. In step S201, the autosampler 203 transports a waste liquid container to the capillary sample introduction end 204. This waste liquid container contains water for dissolving the waste separation medium pushed out from the capillary. In step S202, the syringe 101 is operated to push out the used separation medium into the waste liquid container and inject new separation medium into the capillary.

[0019] In step S203, the autosampler 203 transports the wash water container to the capillary sample introduction end 204 to wash the capillary sample introduction end 204. In step S204, the buffer container is transported to the capillary sample introduction end 204. In step S205, a voltage is applied to the capillary without injecting a sample, to perform a preliminary electrophoresis.

[0020] In step S206, the autosampler 203 transports the cleaning water container to the capillary sample introduction end 204 to clean the capillary sample introduction end 204. In step S207, the autosampler 203 transports the sample container to the capillary sample introduction end 204, and the capillary sample introduction end 204 is immersed in the sample solution in the sample container.

[0021] In step S208, a voltage is applied to the capillary to electrodynamically inject the sample into the capillary. In step S209, the autosampler 203 transports a wash water container to the capillary sample introduction end 204 to wash the capillary sample introduction end 204. In step S210, the autosampler 203 transports a buffer container to the capillary sample introduction end 204. In step S211, a migration voltage is applied to the capillary to perform electrophoresis.

[0022] The operation of the pump unit will be described in detail with reference to Figures 3 to 5. The pump unit has a polymer block 102 having a thin tube 103 formed therein. A syringe 101 is connected to the upper end of the polymer block 102. Tubes 105 and 107 are connected to the lower end of the polymer block 102. The tube 105 has a check valve 104, and its lower end is inserted into a polymer bottle 108. The tube 107 has a flow path switching valve 106, and its lower end is inserted into a buffer container 109. A tube 111 is connected to a side end of the polymer block 102, and a capillary head 112 is connected to the tube 111. The syringe 101, the tubes 105 and 107, and the tube 111 are connected to the thin tube 103 of the polymer block 102.

[0023] In this example, a syringe 101 is used as a means for sucking and discharging the polymer to fill the capillary with the polymer, but other polymer sucking and discharging means such as a pump may also be used. The flow path switching valve 106 may be of any type, such as a pin valve or a rotary valve. The anode electrode 402 is immersed in the buffer in the buffer container 109.

[0024] 3 shows a state in which the flow path switching valve 106 is closed and the syringe 101 is aspirated. The polymer in the polymer bottle 108 flows into the syringe 101 via the tube 105, the check valve 104, and the thin tube 103 in the polymer block 102. As a result, the syringe 101 is filled with the polymer.

[0025] 4 shows a state in which the flow path switching valve 106 is opened and the syringe 101 is pushed out. The polymer in the syringe 101 flows into the buffer container 109 via the capillary tube 103 in the polymer block 102 and the flow path switching valve 106. As the polymer flows into the buffer container 109, negative pressure is created on the discharge side of the check valve 104, and the polymer in the polymer bottle 108 flows into the capillary tube 103 in the polymer block 102 via the check valve 104. As a result, the capillary tube 103 in the polymer block 102 is filled with the polymer, and air bubbles are removed.

[0026] 5 shows the state in which the flow path switching valve 106 is closed again and the syringe 101 is pushed out. The polymer in the syringe 101 flows into the tube 111 via the thin tube 103 in the polymer block 102, and then into the capillary. Because the flow path switching valve 106 is closed, the polymer does not flow into the buffer container 109. As the polymer flows into the capillary, negative pressure is created on the discharge side of the check valve 104, and the polymer in the polymer bottle 108 flows into the thin tube 103 in the polymer block 102 via the check valve 104.

[0027] As the polymer flows into the capillary, the used polymer in the capillary is discharged from the sample introduction end of the capillary.

[0028] In this example, the capillary is filled with the polymer by pressurizing the thin tube 103 in the polymer block 102 from the syringe 101 side. However, the method for filling the capillary with the polymer is not limited to this. For example, the capillary may be filled with the polymer by immersing the sample introduction end 204 of the capillary in a container containing new polymer and depressurizing the thin tube 103 in the polymer block 102 from the syringe 101 side.

[0029] An example of a polymer container according to the present invention will now be described with reference to Figure 6. The polymer container according to the present invention is used in place of the polymer bottle 108.

[0030] A first example of a polymer container according to the present invention will be described with reference to Figure 6. The polymer container 60 of this example is formed in the shape of a bag or pouch made of flexible, preferably pliable, plastic. Instead of plastic, a material with enhanced light-blocking properties, for example, laminated with aluminum, may be used. Alternatively, other flexible materials may be used. An opening 61 is formed at the top of the polymer container 60, and a cap 62 is attached to the opening 61. A thread is formed on the outer surface of the opening 61, which engages with the threads on the cap 62.

[0031] As shown in Figure 6(a), before use, the polymer container 60 is filled with a polymer, which is a separation medium. The polymer container 60 is filled only with the polymer, and no air is enclosed within. In other words, the polymer is vacuum-sealed within the polymer container 60. When in use, as shown in Figure 6(b), the cap 62 is removed and the polymer suction tube 105 is inserted into the opening 61. Next, the fastening cap 63 attached to the tube 105 is engaged with the opening 61. The inner surface of the fastening cap 63 is threaded to engage with the threads of the opening 61. In this way, by engaging the fastening cap 63 with the opening 61 at the top of the polymer container 60, the interior of the polymer container 60 is sealed.

[0032] As shown in Figure 3, when the pump is in suction mode, the inside of the polymer container 60 is suctioned through the tube 105. This causes the polymer inside the polymer container 60 to flow out into the tube 105. As the amount of polymer inside the polymer container 60 decreases, the pressure inside the polymer container 60 decreases, and the polymer container 60 collapses due to atmospheric pressure. However, air does not flow into the polymer container 60. In this way, the polymer container 60 shrinks and deforms until all of the polymer inside the polymer container 60 is suctioned. Hereinafter, the polymer container will be referred to as a "polymer pouch" in this specification.

[0033] As described above, the present invention is premised on the assumption that the polymer bottle 108 is a polymer pouch 60 made of a flexible material, such as soft plastic.

[0034] 7A, 7B, and 7C show an example of a cover (polymer pouch cover) 701 that covers the polymer pouch 60 from the outside. As shown in Fig. 7A, the polymer pouch cover 701 has a convex portion 702 formed on the inner wall surface of the inside of the cover, the convex portion being a continuous line that protrudes toward the inside of the cover. The convex portion 702 has the following characteristics.

[0035] When the polymer pouch 60 is covered with the polymer pouch cover 701, the convex portion 702 presses the polymer pouch 60 toward the inner wall surface on the opposite side, thereby forming a pseudo flow path inside the polymer pouch 60.

[0036] The cover can be fixed to the polymer pouch without external support by using a so-called snap fit 703, Velcro (registered trademark), screws, etc. when the cover is closed.

[0037] Next, the operation of this embodiment will be described with reference to FIGS. 7A, 7B, and 7C. First, as shown in FIG. 7B, the polymer pouch is attached to the tube 105 of the device. Then, as shown in FIG. 7C, the polymer pouch 60 is sandwiched between the polymer pouch cover 701. At this time, a convex portion 702 formed on the inner wall surface of the polymer pouch cover is pressed against the polymer pouch 60, thereby forming a pseudo-flow path within the polymer pouch 60. This allows the polymer 70, which is the content of the polymer pouch 60, to be sucked first from the bottom portion. In other words, by pressing the pressing portion against the polymer pouch from the outside, a pseudo-flow path is formed within the polymer pouch, making it possible to suck the polymer from the bottom portion, which is an area of ​​the polymer pouch that does not contain air bubbles 71.

[0038] When the polymer is sucked in this state, the polymer is preferentially sucked from the bottom where there are very few air bubbles, preventing the air bubbles from being sucked in along with the polymer. As a result, as shown in Figure 7C, the air bubbles 71 that were present in the polymer pouch are retained inside the polymer pouch.

[0039] According to this embodiment, it is possible to effectively prevent air bubbles from being mixed into the flow path in the pump block when the polymer is sucked in. Therefore, it is possible to prevent damage to the flow path due to air bubbles and reduce the amount of polymer consumed.

[0040] Figures 7A, 7B, and 7C illustrate a pressing portion shaped like an eight, but this pressing portion may have any shape as long as it can press the polymer pouch from the outside to form a bubble-blocking path inside the polymer pouch so that air bubbles are not sucked into the polymer suction pipe.

[0041] FIG. 8A shows an example (first example) of the shape of the pressing portion. Since it is sufficient to prevent bubbles that rise to the top due to differences in specific gravity from being sucked into the tube (hereinafter also referred to as the suction pipe) 105, an upwardly open V-shape such as (1)(1)' may be used. In this case, it is preferable that the shape is line-symmetrical about the suction pipe. Linear symmetry allows the polymer pouch to be pressed evenly in the left-right direction, thereby enabling the bubble blocking effect to be symmetrical on the left and right. Similarly, any combination of (2)(2)', (3)(3)', (4)(4)', or (5)(5)' may be used. It is desirable to minimize gaps in the pressing portion near the suction pipe 105. Eliminating gaps makes it possible to avoid the problem of bubbles passing through.

[0042] FIG. 8B shows another example (second example) of the shape of the pressing portion. FIG. 8B shows an example in which a pressing portion is located at the position (3)(3)' in FIG. 8A, particularly showing the three-dimensional structure of the pressing portion. As shown in FIG. 7C, even when the pouch cover 701 is closed, there is a gap between the opposing pouch covers. Therefore, the suction pipe 105 is configured to surround the suction pipe to prevent air bubbles from slipping through the gap between the pressing portion and the suction portion. Providing a pressing portion at the position (3)(3)' in FIG. 8A has the advantages of a simple structure and a small dead volume of polymer due to the small volume of pressure. In this second example, the suction port is located at the top of the pouch, but if the air bubbles are sufficiently large, it is possible to suppress air bubbles from escaping from the edge of the convex portion. Furthermore, since the suction port does not need to be configured to face downward, the pressing portion can function to suppress air bubble suction even when the suction port is open to the side of the suction pipe, for example.

[0043] Figure 8C shows yet another example (third example) of the shape of the pressing portion. Figure 8C shows an example in which a pressing portion is located at the position (5)(5)' in Figure 8A, and particularly shows the three-dimensional structure of the pressing portion. When the pressing portion is extended to a position corresponding to the vicinity of the bottom surface of the polymer pouch where no air bubbles are contained in the polymer, as in this third example, the polymer can be selectively sucked from the bottom surface of the polymer pouch. Therefore, even if the suction port is located at the top of the pouch, it is possible to prevent air bubbles from being sucked in from the edge of the convex portion, regardless of the size of the air bubbles, i.e., even if the air bubbles are small, which is an advantage.

[0044] 9A, 9B, 9C, and 9D are diagrams showing an example of a polymer pouch cover in Example 2, which is a modified example of Example 1. Unlike Example 1, this Example has one or more substantially linear convex walls 805 on the inside of a polymer pouch cover 804, as shown in Fig. 9A, and does not have the linear convex portion that protrudes inward toward the cover as shown in Fig. 9A. The other parts are the same as those in Example 1.

[0045] The operation of this embodiment is as follows. First, a polymer pouch filled with a polymer is prepared as shown in FIG. 9B. When the polymer pouch is placed with its inlet facing up, any air bubbles trapped inside it will gather near the inlet. Next, the polymer pouch 60 is rotated so that its inlet faces downward, as shown in FIG. 9C. The air bubble 71 inside the polymer pouch 60 is moved from end A near the inlet of the polymer pouch 60 to end B, which is farther away. The cover 804 is then placed to hold the air bubble in place. By placing the cover 804, one or more substantially linear, convex walls act to hold the polymer pouch 60, fixing the position of the air bubble at end B. After confirming that the air bubble 71 has been held down and fixed near the bottom edge on the side opposite the inlet, the polymer pouch 60 is attached to the tube 105 of the device, as shown in FIG. 9D, and the polymer is aspirated.

[0046] By suppressing the air bubbles with cover 804, even when the pouch is inserted into the inlet of polymer pouch 60 with the inlet facing up, the air bubbles remain fixed near the bottom side opposite the inlet. Therefore, even when the polymer is sucked in, it is less likely that the air bubbles will be sucked in along with the polymer.

[0047] According to this embodiment, even when a cover is used in which the inner wall surface of the cover does not have a linear convex portion that is raised inward, it is possible to effectively prevent air bubbles from entering the flow path in the pump block during polymer suction. Therefore, with a simpler cover configuration, it is possible to prevent damage to the flow path due to air bubbles and reduce polymer consumption.

[0048] 10A and 10B are diagrams showing an example of a polymer pouch cover in Example 3, which is a modified example of Example 1. Unlike Example 1, this example has one or more substantially linear convex walls on the inside of a polymer pouch cover 804, and does not have the convex portion shown in FIG. 7A , which is a continuous line of convex portions that protrude toward the inside of the cover. The other parts are the same as those in Example 1.

[0049] The operation of this embodiment is as follows. First, as shown in FIG. 10A, the polymer pouch is attached to the tube (hereinafter also referred to as the suction tube) 105 on the device side. This connects the device side and the polymer pouch 60 to each other. Then, the polymer pouch cover is placed over the polymer pouch. Furthermore, as shown in FIG. 10B, by pushing the cover up near the entrance of the polymer pouch, the polymer is pushed up and the air bubbles are fixed at a position higher than the air bubble suction port. Therefore, even when the polymer is sucked through the suction tube 105, it is less likely that the air bubbles will be sucked in along with the polymer.

[0050] According to this embodiment, even when a cover is used in which the inner wall surface of the cover does not have a linear convex portion that is raised inward, it is possible to effectively prevent air bubbles from entering the flow path in the pump block during polymer suction. Therefore, with a simpler cover configuration, it is possible to prevent damage to the flow path due to air bubbles and reduce polymer consumption.

[0051] 10...pump unit, 20...autosampler unit, 30...irradiation / detection unit, 40...high-voltage power supply unit, 50...thermostat unit, 60...polymer container, 61...mouth, 62...cap, 63...fastening cap, 70...polymer, 71...air bubble, 72...cap, 80...wide-mouth bottle, 81...lid, 91...liquid level, 92...drop lid, 101...syringe, 102...polymer block, 103...narrow tube, 104...check valve, 105...tube, 106...flow path switching valve, 107...tube, 108...polymer bottle, 109...buffer container, 110...capillary array, 111...tube, 112...capillary head, 201...sample container, 202...buffer reservoir, 203...autosampler, 204...capillary sample introduction end, 301...capillary detection unit, 302...excitation light, 303...signal detection mechanism, 401...capillary sample introduction end side electrode, 402...anode side electrode, 403...high voltage power supply, 501...thermostat

Claims

1. An electrophoresis apparatus comprising: a capillary filled with a polymer; a polymer pouch containing the polymer; and a pump for transferring the polymer from the polymer pouch to the capillary, wherein the electrophoresis apparatus further comprises a polymer pouch cover for holding the polymer pouch from the outside, the polymer pouch cover having a pressing portion for forming an air bubble blocking path inside the polymer pouch by pressing the polymer pouch.

2. An electrophoresis device as claimed in claim 1, characterized in that a suction pipe for sucking the polymer from the polymer pouch is inserted into the polymer pouch, and the pressing part has a portion extending from the vicinity of the suction pipe towards the outside of the polymer pouch.

3. An electrophoretic device according to claim 2, characterized in that the outwardly extending portion is continuous and linear.

4. An electrophoresis device as claimed in claim 2, characterized in that the outwardly extending portion is shaped like an inverted V-shape that opens downwards when viewed from the top surface of the polymer pouch cover, and the upper portion is closed by the suction pipe.

5. An electrophoresis device according to claim 1, wherein the outwardly extending portion has a horizontal line shape when viewed from the top surface of the polymer pouch cover.

6. An electrophoresis apparatus comprising: a capillary filled with a polymer; a polymer pouch containing the polymer; and a pump for transferring the polymer from the polymer pouch to the capillary, wherein the electrophoresis apparatus further comprises a polymer pouch cover for holding the polymer pouch from the outside, and the polymer pouch cover has a convex portion on its inner wall surface that is a linear series of portions that are convexly raised toward the inside of the cover, and when the polymer pouch cover sandwiches the polymer pouch, the convex portion presses against the polymer pouch to form a bubble-blocking path inside the polymer pouch.

7. An electrophoresis device as described in claim 6, characterized in that the polymer pouch cover clamps the polymer pouch at a position spaced a predetermined distance or more from the entrance thereof, and while the convex wall acts to press down on the polymer pouch, the wall is pushed up towards the polymer suction port, thereby fixing the air bubble at a position spaced a predetermined distance or more from the polymer suction port.

8. An electrophoresis device according to any one of claims 1 to 7, characterized in that the polymer pouch cover is made of a pair of members that sandwich the polymer pouch, and the pair of members has an engaging member that engages with a part of the electrophoresis device.

9. An electrophoresis device according to any one of claims 1 to 6, characterized in that the polymer pouch cover is made of a pair of members that sandwich the polymer pouch, and the pair of members have engaging members that engage when brought together.

10. A polymer pouch cover for use in the electrophoresis device according to any one of claims 1 to 7.

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