Electrophoresis device

Abstract

The purpose of the present invention is to provide an electrophoresis device in which deterioration of analysis performance is suppressed and the degree of freedom of selection of a laser device is high. To this end, the present invention is an electrophoresis device that irradiates laser light from both ends of a capillary array in which a plurality of capillaries are arranged and detects light from the plurality of capillaries, and an optical isolator is provided on an optical path from a light source of the laser light to the capillary array. Thus, even if laser light is not irradiated in a state of being inclined with respect to the capillary axis, the reflection of return light can be suppressed, and an electrophoresis device having high analysis performance can be provided. In addition, the transmitted return light and the reflected return light can be reliably suppressed, so that the degree of freedom of selection of the laser device becomes high.

Description

Technical Field

[0001] The present invention relates to an electrophoresis device. Background Art

[0002] In a multi-focusing capillary electrophoresis device, a capillary array consisting of a plurality of capillaries arranged in a row is irradiated with laser light from both ends, and uniform signal intensity is detected from all capillaries. In such a multi-focusing method, reflected return light and transmitted return light from the capillaries may return to the laser unit as a light source, resulting in unstable laser oscillation, which may adversely affect analytical performance.

[0003] Patent document 1 describes an electrophoresis device that suppresses reflected return light and transmitted return light. For example, FIG. 11 (Example 6) of Patent document 1 discloses a technique of using a polarizer and a half-wave plate to make the laser light irradiated from both ends to the capillary array perpendicular to the capillary axis and suppress the transmitted return light. In addition, FIG. 12 (Example 7) of Patent document 1 discloses a technique of irradiating the capillary array with a laser light at an angle deviating from the perpendicular to the capillary axis in order to suppress the reflected return light.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: U.S. Patent Application Publication No. 2003 / 0226756 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the technology of FIG. 11 of Patent Document 1, when the polarization state of the laser is destroyed when passing through the capillary array, the light after passing through the half-wavelength plate also produces a deviation in the polarization angle, and a part of the components pass through the polarizer, so it is difficult to completely block the transmitted return light. In addition, in this technology, it is difficult to suppress the reflected return light, so it is necessary to use a laser unit with strong resistance to the return light, and the degree of freedom in the selection of the laser device is low. In addition, in the technology of FIG. 12 of Patent Document 1, the laser is irradiated in a state tilted relative to the capillary axis, so the irradiation area of ​​the laser becomes wider, and it is possible to generate a false signal based on the spectrum shift. When a false signal is generated, the sample separation performance of the electrophoresis device is deteriorated.

[0009] An object of the present invention is to provide an electrophoresis device that suppresses degradation of analytical performance and has a high degree of freedom in selecting a laser device.

[0010] Means for solving problems

[0011] To solve the above problems, the present invention is an electrophoresis device that irradiates laser light from both ends of a capillary array in which a plurality of capillaries are arranged and detects light from the plurality of capillaries, wherein an optical isolator is provided on the optical path from the laser light source to the capillary array.

[0012] Effects of the Invention

[0013] According to the present invention, even if the laser is not irradiated in a tilted state relative to the capillary axis, the reflected return light can be suppressed, so that an electrophoresis device with high analytical performance can be provided. In addition, the transmitted return light and the reflected return light can be reliably suppressed, so the freedom of selection of the laser device becomes higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the electrophoresis device according to this embodiment.

[0015] Figure 2 This is a diagram showing the movement of a DNA band separated by electrophoresis in a capillary.

[0016] Figure 3 This is a graph showing an example of changes in the emission spectrum.

[0017] Figure 4 This is a diagram schematically showing the path of laser light in the optical irradiation system of the electrophoresis device of Example 1.

[0018] Figure 5A This is a diagram showing a situation where laser light is incident on a polarization-dependent optical isolator in the forward direction.

[0019] Figure 5B This is a diagram showing a situation where the return light is incident on the polarization-dependent optical isolator in the reverse direction.

[0020] Figure 6 This is a conceptual diagram showing transmitted return light and reflected return light when a capillary array is irradiated with laser light.

[0021] Fig. 7A This diagram shows the linear polarization states of laser light incident on a polarization-dependent optical isolator and irradiating the capillary array from below, and its transmitted return light.

[0022] Figure 7B This figure shows the polarization states of laser light incident on a polarization-dependent optical isolator and irradiating the capillary array from above, and its transmitted return light.

[0023] Fig. 8A This is a diagram showing the optical path of laser light that is incident on a polarization-independent optical isolator from the forward direction and the polarization direction at each position as viewed from the direction in which the light beam travels.

[0024] Figure 8BThis is a diagram showing the optical path of the return light incident on the polarization-independent optical isolator from the reverse direction and the polarization direction of each position observed from the traveling direction of the light beam.

[0025] Fig.9A This diagram shows the linear polarization states of laser light that is incident on a polarization-independent optical isolator and irradiates the capillary array from below, and its transmitted return light.

[0026] Fig. 9B This diagram shows the linear polarization states of laser light incident on a polarization-independent optical isolator and irradiating the capillary array from above, and its transmitted return light. DETAILED DESCRIPTION

[0027] use Figure 1 , the structure of the electrophoresis device according to the embodiment of the present invention is described. Figure 1 Schematic diagram of the electrophoresis device of this embodiment. Figure 1 As shown, the electrophoresis device 101 includes: a capillary array 117 composed of one or more capillaries 102; a thermostatic bath 118 for maintaining the capillary 102 at a constant temperature; a high voltage power supply 104 for applying voltage to the capillary 102; a pump mechanism 103 for injecting a polymer into the capillary 102; and a conveying mechanism 125. The conveying mechanism 125 is a mechanism for conveying a buffer container 121, a cleaning container 122, a waste liquid container 123, and a sample container 124 to a capillary cathode terminal 127.

[0028] The capillary array 117 includes a loading head 129 disposed at one end, a capillary head 112 disposed at the other end, and a detection unit 116 formed between the loading head 129 and the capillary head 112 and detecting a sample electrophoresed in the capillary 102. The capillary array 117 is composed of, for example, 24 capillaries 102, and when the measurement method is changed, the capillary array 117 is replaced with a capillary array having a different capillary length. In addition, when the capillary 102 is observed to be damaged or deteriorated in quality, it is also replaced with a new capillary array 117.

[0029] The capillary 102 is formed of a glass tube with an inner diameter of 50 μm and an outer diameter of 320 μm, and the surface is coated with polyimide to improve strength. However, the detection unit 116 in the capillary 102 that is irradiated with laser light is removed from the polyimide coating so that the light emitted from the inside is easily leaked to the outside. The interior of the capillary 102 is filled with a separation medium for imparting a migration difference during electrophoresis by the pump mechanism 103. In this embodiment, a polymer as a high-viscosity solution is used as the separation medium.

[0030] The capillary cathode ends 127 are fixed by metal hollow electrodes 126, respectively, and the front ends of the capillaries 102 protrude about 0.5 mm from the hollow electrodes 126. In addition, all the hollow electrodes 126 equipped on each capillary 102 are integrated and mounted on the loading head 129. In addition, all the hollow electrodes 126 are connected to the high-voltage power supply 104 mounted on the device body, and operate as cathode electrodes when voltage is applied during electrophoresis, sample introduction, etc.

[0031] The capillary ends on the side opposite to the capillary cathode end 127 are bundled and bonded by a capillary head 112. The capillary head 112 is connected to the block 107 in a pressure-tight manner. Then, a new polymer is filled into the capillary 102 by the pump mechanism 103. In order to improve the performance of the measurement, the polymer in the capillary 102 is refilled every time the measurement is performed.

[0032] The optical system is composed of a light irradiation mechanism 114 for irradiating the detection section 116, an array holder 105 for holding the detection section 116, a spectrometer 132 for splitting the light emitted in the detection section 116 into wavelengths, and a two-dimensional detector 115 for detecting the split light. When detecting the sample in the capillary 102 separated by electrophoresis, the detection section 116 is irradiated by the light irradiation mechanism 114, and the light emitted from the detection section 116 is split by the spectrometer 132, and then detected by the two-dimensional detector 115.

[0033] The constant temperature bath 118 is covered with a heat insulating material, and the interior thereof is controlled to a constant temperature by a heating and cooling mechanism 120. In addition, a fan 119 circulates and stirs the air in the constant temperature bath 118 to keep the temperature of the capillary array 117 uniform and constant.

[0034] The pump mechanism 103 is composed of a plunger pump 106, a block 107, a check valve 108, an electric valve 113, a polymer container 109 and an anode buffer container 110. A flow path that connects the plunger pump 106, the polymer container 109, the anode buffer container 110 and the capillary array 117 is provided in the block 107. A check valve 108 that prevents polymer backflow is provided in the flow path between the plunger pump 106 and the polymer container 109. An electric valve 113 is provided in the flow path between the block 107 and the anode buffer container 110. When the chamber 128 of the plunger pump 106 and the capillary array 117 are filled with polymer, the electric valve 113 is closed to prevent the buffer from flowing into the anode buffer container 110. When electrophoresis is performed, the electric valve 113 is opened, and the anode electrode 111 and the capillary cathode end 127 are energized.

[0035] The conveying mechanism 125 is provided with three electric motors and linear actuators not shown in the figure, and can move along three axes, namely, up and down, left and right, and depth. In addition, one or more containers can be placed on the moving table 130 of the conveying mechanism 125. In addition, the moving table 130 is provided with an electric handle 131, which can grasp and release each container. Therefore, the buffer container 121, the cleaning container 122, the waste liquid container 123, and the sample container 124 can be conveyed to the loading head 129 as needed. In addition, unnecessary containers are stored in a predetermined storage place in the device.

[0036] Here, an overview of a pseudo signal due to a spectrum shift is described. Figure 2 : is a diagram showing the state of a DNA band separated by electrophoresis moving in a capillary. The detection portion 116 of the capillary 102 is irradiated with a focused laser, and the laser has an irradiation area 702 of a predetermined width. Therefore, the signal obtained by the two-dimensional detector 115 changes during the period from when the DNA band 701 enters the irradiation area 702 of the laser to when it comes out. In addition, since the swimming direction is equal to the wavelength dispersion direction, the DNA band 701 moves in the wavelength dispersion direction while passing through the irradiation area 702 of the laser. Therefore, the emission spectrum 703 of the signal obtained by the two-dimensional detector 115 looks like this. Figure 3 Changes as shown.

[0037] Figure 3 This is a graph showing an example of changes in the emission spectrum. Figure 3 Such a spectrum shift gives the same effect as the wavelength change of the luminescence spectrum 703 over time during the period when the DNA band 701 passes through the irradiation area 702 of the laser. In the electrophoresis method, multiple fluorescent pigments are used, and each fluorescent pigment corresponds to four bases. Therefore, when the luminescence spectrum 703 changes in appearance, it is impossible to make the observed luminescence spectrum 703 completely correspond to each fluorescent pigment or each base (matrix transformation). That is, when the components of the luminescence spectrum 703 are matrix-transformed, a false signal as a residual component that cannot be transformed is generated. The false signal becomes the cause of reduced recognition ability of the fluorescent pigment or misdiagnosis. When the irradiation area 702 of the laser widens, the false signal caused by the spectrum shift becomes larger.

[0038] Example 1

[0039] Figure 41 is a diagram schematically showing the path of laser light in the optical irradiation system of the electrophoresis device of Example 1. The light irradiation mechanism 114 in this example includes: a laser unit 201 as a light source for oscillating laser light 202; a beam splitter 205 for branching the laser light 202 into two; a reflector 203 for changing the path of the laser light 202; and a condenser lens 206 for condensing the laser light 202. A polarization-dependent optical isolator 204 is inserted in the optical path from the laser unit 201 to the beam splitter 205. One of the laser light 202 branched by the beam splitter 205 is guided to the lower side of the capillary array by the reflector 203, and the other is guided to the upper side of the capillary array by the reflector 203. Then, each laser light 202 is condensed by the condenser lens 206 and enters the capillary array from the upper end or the lower end, and the fluorescence emitted from the detection unit 116 of each capillary 102 is detected by the two-dimensional detector 115.

[0040] In addition, Figure 4 207. Although only five capillaries 102 are shown in the figure, in this embodiment, the capillary array is composed of 24 capillaries 102, and each capillary 102 is arranged and fixed on the reference base 207 in the detection unit 116. In this specification, the virtual plane formed by the central axis (capillary axis) of each capillary on the reference base 207 is called the capillary arrangement plane, and the virtual straight line perpendicular to each capillary axis in the capillary arrangement plane is called the optical axis 208. In addition, in this embodiment, the capillary array is composed of 24 capillaries 102, but the number of capillaries 102 is not limited to 24.

[0041] use Figure 5A and Figure 5B , which represents the shielding principle of the polarization-dependent optical isolator 204 . Figure 5A This is a diagram showing the case where laser light is incident on a polarization-dependent optical isolator in the forward direction. Figure 5B 204 is a diagram showing a case where the return light is incident on the polarization-dependent optical isolator in the reverse direction. The polarization-dependent optical isolator 204 is composed of a first polarizer 302a, a second polarizer 302b, and a Faraday rotator 301 located between the first polarizer 302a and the second polarizer 302b. Here, the second polarizer 302b is set in a state where the transmission axis is tilted 45° relative to the first polarizer 302a. In addition, the Faraday rotator 301 rotates the polarization direction 303 by a predetermined angle regardless of the incident direction and the polarization direction. In this embodiment, the Faraday rotator 301 that rotates the polarization direction by 45° is used. However, the rotation direction of the polarization direction 303 rotated by the Faraday rotator 301 for the forward incident light is opposite to the rotation direction of the polarization direction 303 rotated by the Faraday rotator 301 for the reverse incident light.

[0042] like Figure 5AAs shown, when the laser is incident on the polarization-dependent optical isolator 204 from the forward direction, the laser passes through the first polarizer 302a, and then the polarization direction of the laser is rotated by 45° in the Faraday rotator 301, and then the laser is incident on the second polarizer 302b. The transmission axis of the second polarizer 302b is tilted by 45°, so the laser passes through the second polarizer 302b.

[0043] On the other hand, Figure 5B As shown in FIG. 1 , when the return light is incident on the polarization-dependent optical isolator 204 from the reverse direction, the return light is transmitted through the second polarizer 302b, and then the polarization direction of the return light is rotated by 45° in the Faraday rotator 301 in the direction opposite to that of the forward direction, and then the return light is incident on the first polarizer 302a. At this time, the polarization direction of the return light is perpendicular to the transmission axis of the first polarizer 302a, and thus the return light is blocked by the first polarizer 302a.

[0044] Here, use Figure 6 The outline of reflected return light and transmitted return light is described below. Figure 6 This is a conceptual diagram showing the transmitted return light and reflected return light when a laser is irradiated to a capillary array. Figure 6 In order to easily determine the transmitted light and reflected light from the capillary array, the incident light to the capillary array is shown slightly tilted from the direction perpendicular to the capillary axis for convenience.

[0045] When the laser 202 is incident on the capillary array, the laser 202 is reflected at the interface between the air and the outer wall of the capillary and at the interface between the inner wall of the capillary and the gel. In particular, at the former interface, the intensity of the reflected light increases due to the large refractive index. There are two interfaces between the air and the outer wall of the capillary for one capillary, so in the capillary array consisting of 24 capillaries, a total of 48 reflections occur at the interface between the air and the outer wall of the capillary. When the reflected return light 401 from the capillary array reaches the laser unit 201 as a light source, the laser oscillation generated by the laser unit 201 becomes unstable.

[0046] In addition, the transmitted light that passes through the capillary array and is released from the side opposite to the incident side is the transmitted return light 402. Compared with the incident light, the amount of the reflected light is attenuated in the transmitted return light 402. When the transmitted return light 402 reaches the laser unit 201, the laser oscillation generated by the laser unit 201 becomes unstable.

[0047] Fig. 7A This diagram shows the linear polarization states of laser light incident on a polarization-dependent optical isolator and irradiating the capillary array from below, and its transmitted return light. Fig. 7A The xy plane is a plane perpendicular to the direction of travel of the laser and represents the linear polarization state at each position ( Figure 7B , Fig.9A and Fig. 9B Also, in Fig. 7A In the figure, the reflecting mirror is omitted and the position of the beam splitter is indicated as point A. The laser light emitted from the laser unit 201 is incident on the polarization-dependent optical isolator 204 in a linear polarization state in the x-axis direction. The laser light incident on the polarization-dependent optical isolator 204 is incident in the forward direction, so Figure 5A As shown in FIG. 1 , the linear polarized light passes through the beam splitter (point A) in a state of being rotated by 45°. The laser light traveling straight through the beam splitter (point A) is incident on the capillary array 117 from below at a polarization angle of 45°. The transmitted return light through the capillary array 117 directly follows another laser path and is incident on the polarization-dependent optical isolator 204 again. However, since it is incident in the opposite direction, Figure 5B As shown, it is blocked by the first polarizer 302a. Fig. 7A Although not shown in the figure, the incident light enters the polarization-dependent optical isolator 204 at the same polarization angle while following the path of the incident light, and is therefore blocked in the same manner as the transmitted return light.

[0048] Figure 7B This diagram shows the polarization state of the laser beam incident on the capillary array from above and its transmitted return light after entering the polarization-dependent optical isolator. Fig. 7A The laser light emitted from the laser unit 201 enters the polarization-dependent optical isolator 204 in a linear polarization state in the x-axis direction, and passes through the polarization-dependent optical isolator 204 in a state where the linear polarization light is rotated by 45°. The laser light reflected from the beam splitter (point A) enters the capillary array 117 from above with a polarization angle of 45°. The transmitted return light that has passed through the capillary array 117 enters the polarization-dependent optical isolator 204 again after following another laser path, but the same as Fig. 7A The same is true for the case where the reflected light is blocked by the first polarizer 302a. Figure 7B Although not shown in the figure, the incident light enters the optical isolator at the same polarization angle while following the path of the incident light, and is therefore blocked in the same manner as the transmitted return light.

[0049] In this embodiment, even if the polarization state of the laser light is destroyed when irradiating the capillary array and the polarization angle of the return light is deviated, Figure 5BAs shown, only the linearly polarized light with a polarization angle of 45° passes through the second polarizer 302b and enters the Faraday rotator 301. In addition, in the Faraday rotator 301, since the polarization direction of the return light rotates oppositely to the forward direction, the return light is blocked by the first polarizer 302a. That is, the polarization-dependent optical isolator of this embodiment plays a role in reliably blocking the return light even if the state of the linearly polarized light is destroyed due to the laser irradiation to the capillary array. Therefore, a laser unit with low tolerance to the return light can also be used, and the freedom of choice of the laser device is improved. In addition, the optical axis of the laser irradiated to the capillary array from both ends is coaxial and perpendicular to the capillary axis, so the irradiation area of ​​the laser is narrowed, which can reduce the analog signal caused by the spectral shift. As a result, the sample separation performance of the electrophoresis device is improved.

[0050] Example 2

[0051] use Figures 8A to 9B The optical irradiation system of the electrophoresis device of Example 2 is described. Unlike Example 1, the light irradiation mechanism 114 of this example includes a polarization-independent optical isolator 801 as an optical isolator.

[0052] like Fig. 8A and Figure 8B As shown, the polarization-independent optical isolator 801 is composed of a first birefringent crystal 803a, a second birefringent crystal 803b, a Faraday rotator 301 located between the first birefringent crystal 803a and the second birefringent crystal 803b, a half-wavelength plate 802 located between the first birefringent crystal 803a and the second birefringent crystal 803b, and a pinhole plate 804.

[0053] Here, the Faraday rotator 301 uses the same Faraday rotator as in Example 1, but in this example, a half-wavelength plate 802 is also used. The half-wavelength plate 802 also rotates the polarization direction by 45° like the Faraday rotator 301. However, unlike the case of the Faraday rotator 301, the rotation direction of the polarization direction rotated by the half-wavelength plate 802 for the forward incident light is the same as the rotation direction of the polarization direction 303 rotated by the half-wavelength plate 802 for the reverse incident light.

[0054] Fig. 8A 803a is a diagram showing the optical path followed by the laser light incident from the forward direction to the polarization-independent optical isolator and the polarization direction of each position observed from the direction of the light beam. The laser light 202 traveling in the forward direction passes through the pinhole of the pinhole plate 804 and is incident on the first birefringent crystal 803a. The first birefringent crystal 803a separates the laser light 202 into the normal light 806 and the extraordinary light 807 whose polarization directions differ by 90° by the difference in refractive index in each axial direction. In this embodiment, it is assumed that the polarization of the normal light 806 is perpendicular to Fig. 8AAfter each light beam is rotated 45° by the Faraday rotator 301, it is further rotated 45° in the same direction by the half-wavelength plate 802, so that the polarization direction is rotated by 90° in total, and then it is recombined by the second birefringent crystal 803b.

[0055] Figure 8B 803a. The figure shows the optical path followed by the return light incident from the reverse direction to the polarization-independent optical isolator and the polarization direction of each position observed from the direction of the light beam. When the return light 808 traveling in the reverse direction is incident on the second birefringent crystal 803b, it is separated into the ordinary light 806 and the extraordinary light 807. After each light is rotated 45° by the half-wave plate 802, it is rotated 45° in the reverse direction by the Faraday rotator 301, so that the polarization direction remains in the original state and is incident on the first birefringent crystal 803a. However, since the polarization direction of each light in the first birefringent crystal 803a is the same as that after passing through the second birefringent crystal 803b, each light does not recombine and passes through the first birefringent crystal 803a in a separated state and is blocked by the pinhole plate 804.

[0056] Fig.9A 801 is a diagram showing the linear polarization state of the laser light incident on the capillary array from below after entering the polarization-independent optical isolator and the light transmitted back. The laser light incident on the polarization-independent optical isolator 801 is incident in the forward direction, so Fig. 8A As shown, the laser beam passing through the polarization-independent optical isolator 801 is incident on the capillary array 117 from below. The transmitted return light passing through the capillary array 117 directly follows another laser path and is incident on the polarization-independent optical isolator 801 again. However, since the incident light is in the opposite direction, Figure 8B As shown, it is blocked by the pinhole plate 804. In addition, although the reflected return light Fig.9A Although not shown in the figure, after following the path of the incident light, it is incident again on the polarization-independent optical isolator 801 and is blocked in the same way as the transmitted return light.

[0057] Fig. 9B This diagram shows the linear polarization state of the laser light incident on the capillary array from above and its transmitted return light after entering the polarization-independent optical isolator. Fig.9A The laser beam incident on the polarization-independent optical isolator 801 passes through the polarization-independent optical isolator 801. After that, the laser beam reflected by the beam splitter (point A) is incident on the capillary array 117 from above. The transmitted return light that has passed through the capillary array 117 directly follows another laser path and is incident on the polarization-independent optical isolator 801 again, but is blocked by the pinhole plate 804. In addition, although the reflected return light is Fig. 9BAlthough not shown in the figure, the incident light enters the polarization-independent optical isolator 801 again after following the path of the incident light, and is blocked in the same way as the transmitted return light.

[0058] In the case of the polarization-dependent optical isolator of Example 1, even if there is a deviation in the return light, the light other than the specific polarization angle can be blocked by the polarizer, so the return light suppression effect is high, but in the case of the polarization-independent optical isolator of this embodiment, the return light suppression effect can also be expected to a certain extent. That is, according to this embodiment, a laser unit with low resistance to return light can also be used, and the freedom of choice of the laser device is improved. In addition, the irradiation area of ​​the laser is narrow, which can reduce the false signal caused by the spectrum shift, so the sample separation performance of the electrophoresis device is also improved.

[0059] The present invention is not limited to the above-mentioned embodiments, and various modifications are possible. For example, in the above-mentioned embodiments, an optical isolator is provided on the optical path from the light source to the beam splitter, so that the number of optical isolators is one, but an optical isolator may be provided on each optical path after the optical path is branched by the beam splitter.

[0060] Explanation of symbols

[0061] 101 ... electrophoresis device, 102 ... capillary, 103 ... pump mechanism, 104 ... high voltage power supply, 105 ... array holder, 106 ... plunger pump, 107 ... block, 108 ... check valve, 109 ... polymer container, 110 ... anode buffer container, 111 ... anode electrode, 112 ... capillary head, 113 ... electric valve, 114 ... light irradiation mechanism, 115 ... two-dimensional detector, 116 ... detection unit, 117 ... capillary array, 118 ... constant temperature bath, 119 ... fan, 120 ... heating and cooling mechanism, 121 ... buffer container, 122 ... cleaning container, 123 ... waste liquid container, 124 ... sample container, 125 ... transport mechanism, 126 ... hollow electrode, 127 ... capillary cathode end, 128 ... chamber, 129 ... loading head, 1 30…moving stage, 131…handle, 201…laser unit, 202…laser, 203…reflector, 204…polarization-dependent optical isolator, 205…beam splitter, 206…condensing lens, 207…reference base, 208…optical axis, 301…Faraday rotator, 302a…first polarizer, 302b…second polarizer, 303…polarization direction, 401…reflected return light, 402…transmitted return light, 701…DNA strip, 702…irradiation area, 703…luminescence spectrum, 801…polarization-independent optical isolator, 802…half-wavelength plate, 803a…first birefringent crystal, 803b…second birefringent crystal, 804…pinhole plate, 806…normal light, 807…abnormal light, 808…return light.

Claims

1. An electrophoresis device, which irradiates laser light from both ends of a capillary array in which a plurality of capillaries are arranged, and detects light from the plurality of capillaries, characterized in that: An optical isolator is provided on the optical path from the laser light source to the capillary array.

2. The electrophoresis device according to claim 1, characterized in that: The optical axis of the laser beam irradiated to the capillary array from both ends is coaxial, perpendicular to the capillary axis and parallel to the arrangement plane of the capillary array.

3. The electrophoresis device according to claim 1, characterized in that: The electrophoresis device comprises: A beam splitter that splits the laser light oscillated from the light source into two beams; and A reflecting mirror guides the branched laser light to one side and the other side of the capillary array, and the optical isolator is provided on an optical path from the light source to the beam splitter.

4. The electrophoresis device according to claim 1, characterized in that: The optical isolator is a polarization-dependent optical isolator having a first polarizer, a second polarizer, and a Faraday rotator located between the first polarizer and the second polarizer.

5. The electrophoresis device according to claim 1, characterized in that: The optical isolator is a polarization-independent optical isolator having a first birefringent crystal, a second birefringent crystal, a Faraday rotator located between the first birefringent crystal and the second birefringent crystal, and a half-wavelength plate located between the first birefringent crystal and the second birefringent crystal.

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