JP2008008808A - Capillary electrophoretic system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized capillary electrophoretic system constituted so as to facilitate capillary replacing work. <P>SOLUTION: The capillary electrophoretic system is equipped with an electrophoretic part 3 wherein electrodes are arranged to both end parts of a capillary 2, a sample liquid feed part 7 for feeding a sample liquid to both end parts of the capillary 2, a capillary holding part 4 constituted so as to hold the capillary 2 and composed of two plates detachable from the capillary electrophoretic system, a sample liquid detecting part 5 having the through-hole provided to a part of the capillary holding part 4 and acquiring the data of electrophoresis from the through-hole and a temperature control part 6 for controlling the temperature of the capillary holding part 4. Since the top surface of the housing 1 provided to the upper part of the capillary holding part 4 is openable and closable, the detachment of the capillary 2 can be easily performed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a capillary electrophoresis apparatus, and more particularly to a technique for facilitating capillary replacement work.

  Hereinafter, a conventional capillary electrophoresis apparatus will be described. As shown in FIG. 4, a conventional capillary electrophoresis apparatus has a flexible capillary 42 attached in an inverted U shape in a constant temperature layer 43 provided at the center of a housing 41. There is a type in which a sample solution is electrophoresed from one end to the other end to analyze the molecular weight of a biological sample, for example.

  Hereinafter, the configuration of the apparatus will be described in the order of the analysis operation. Both ends of the capillary 42 are immersed in the sample liquid holding containers 44a, 44b, 44c, and 44d supported by the rotating tray when the sample liquid transporting portion 47 made of the rotating tray rotates and moves up and down. Then, the sample solution in the container is introduced into the capillary 42 by being sucked or pressurized by the pump 49.

  Thereafter, the introduced sample solution migrates in the capillary 42 in the vicinity of both ends of the capillary 42 by the voltage applied from the electrode 45 that is also immersed in the sample solution.

  In order to control the temperature inside the capillary 42 when the sample liquid is migrated, the temperature of the capillary 42 is covered with the thermostatic chamber 43, and air for heating or cooling is sent from the temperature control unit 46 attached to a part of the thermostatic chamber 43. The temperature of the capillary 42 was controlled by heat transfer using air.

  The sample liquid detection unit 48 for detecting the sample liquid that migrates in the capillary 42 has a through hole in a part of the thermostatic chamber 43, and changes in light while irradiating laser light or lamp light to the through hole. Was measured with a photodiode or the like, and the relationship between the migration time of the sample solution and the change in light was displayed as a graph or the like.

As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
JP 2003-185629 A

  However, in such a conventional capillary electrophoresis apparatus, it is very difficult to attach or remove the capillary 42 to or from the housing 41. That is, the capillary 42 is attached to and detached from the casing 41 by opening the side face of the casing 41 and further opening the side face of the thermostatic chamber 43, and then the operator thrusts both arms into the constant temperature layer 43. The capillary 42 is attached to the hole for guiding it through the capillary 42, and conversely, it is removed.

  Since the work is performed at the back of the inside of the housing 41, there is a problem that the coating on the surface of the capillary 42 is damaged or the capillary itself is broken. In addition, the operator touches the electrodes 45 located at both ends of the capillary 42, and there is a problem of damaging the apparatus such as bending the electrodes.

  Accordingly, the present invention has been made to solve such problems, and an object of the present invention is to provide a capillary electrophoresis apparatus that is particularly easy to replace a capillary.

  In order to achieve this object, the capillary electrophoresis apparatus of the present invention is detachable from the casing from a casing having a lid that opens at the top and the top of the casing that is opened by the lid. And a capillary holding part for horizontally holding at least a part of the capillary on which electrophoresis is performed, and an electrode for holding the both ends of the capillary and applying a voltage for performing the electrophoresis A sample solution holding unit in which both ends of the capillary and the electrodes are respectively immersed, a temperature control unit disposed below the capillary holding unit and performing temperature control of the capillary via the capillary holding unit, The state of electrophoresis performed in the capillary located below the capillary holder and above it is optically detected. It is characterized in further comprising a sample liquid detection unit for, a.

  According to the capillary electrophoresis apparatus of the present invention, the capillary holding part for holding the capillary is provided on the upper part of the casing, and the capillary holding part can be detached from the upper part of the opened casing. The replacement work can be made very easy, and the intended purpose can be achieved.

  Hereinafter, embodiments of a capillary electrophoresis apparatus of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an overall configuration diagram of a capillary electrophoresis apparatus according to an embodiment of the present invention. The front cover is removed for easy understanding of the internal configuration of the apparatus.

  In FIG. 1, reference numeral 1 denotes a casing constituting a capillary electrophoresis apparatus, and the top surface has a lid structure that can be freely opened and closed. Reference numeral 2 denotes a capillary. In this embodiment, a capillary tube coated with polyimide on a glass tube having an inner diameter of 0.05 mm to 0.1 mm and an outer diameter of 0.3 mm can be used.

  Reference numeral 3 denotes an electrophoresis unit, which has both ends fixed to the capillary 2 and electrodes immersed in the sample solution together with the end of the capillary 2. Reference numeral 4 denotes a capillary holding unit that holds a part of the capillary 2 between the two plates and holds it horizontally at the top of the housing 1.

  Reference numeral 5 denotes a sample liquid detection unit that optically detects the state of electrophoresis in the capillary 2 from below the capillary holding unit 4. A temperature control unit 6 is in contact with the lower surface of the capillary holding unit 4 and controls the temperature of the capillary 2 sandwiched between the capillary holding units 4. Reference numeral 7 denotes a sample liquid transport unit, which includes a tray for holding a container for storing a sample liquid such as a biological sample, and supports the tray so as to be movable in the xyz direction. Note that the sample liquid transport unit does not necessarily have to be configured to be movable in the xyz direction. The sample transport unit 7 is arranged symmetrically with respect to the capillary electrophoresis apparatus, and has a structure bridged by a sheet metal so that the capillary holding unit 4 can be attached to the upper part.

  Reference numeral 8 denotes a high voltage power supply unit for performing electrophoresis, and applies a voltage of −10 kV to 10 kV. Reference numeral 9 denotes a suction pump for filling the sample liquid into the capillary 2 immersed in the container of the sample liquid transport unit 7.

  The operation of the capillary electrophoresis apparatus configured as described above will be described below. Prior to the measurement, the measurement sample is installed in the sample transport unit 7. After the front cover of the housing 1 is opened, the sample transport unit 7 is automatically lowered to the lower limit and then slid to the outside of the front apparatus. For this reason, the user can install the container into which the sample solution has been dispensed without putting the hand inside the apparatus, and the user can install without touching the electrode for electrophoresis protruding inside the apparatus. This eliminates electrode breakage and user damage.

  The capillary 2 is set in the capillary electrophoresis apparatus 1 with its central portion held by the capillary holder 4. Prior to sandwiching the capillary 2 with the capillary holding part 4, only the middle part of the capillary 2 is peeled off from the polyimide coated on the capillary 2, and the peeled part is aligned with the opening of the capillary holding part 4. The capillary 2 is attached by being installed in the groove of the capillary holding part 4. The method of attaching the capillary 2 to the apparatus is to open the top cover of the capillary electrophoresis apparatus 1 and insert it into the hole of the electrophoresis part 3 while bending both ends of the capillary 2 on both sides of the capillary holding part 4. Installation is complete.

  When introducing a sample solution to be subjected to capillary electrophoresis into the capillary 2, the sample solution transport unit 7 moves up and down, left and right, and back and forth, and is pressed against the lower side of the electrophoresis unit 3 to perform electrophoresis with the sample solution container. A sealed space is formed between the portions 3. By sucking with the suction pump 9 from one hole of the electrophoresis unit 3, the sample solution in which the mouth of the capillary 2 opposite to the suction pump is immersed can be introduced into the capillary 2.

  The sample solution introduced into the capillary 2 is moved to the positive electrode side when the sample solution is an anion and to the negative electrode side when the sample solution is a cation by applying a voltage to the electrophoresis unit 3. At this time, due to the difference in flow velocity between the electroosmotic flow and electrophoresis generated in the capillary 2, those having a small molecular weight move fast and those having a large molecular weight move slowly, so that they can be divided by their respective molecular weights.

  In the apparatus of FIG. 1, a negative electrode is disposed on the right side and a positive electrode is disposed on the left side, and the state in which the capillary 2 is electrophoresed from right to left is analyzed. And since the high-voltage power supply unit 8 for performing electrophoresis is arranged below the positive electrode part of the electrophoresis unit 3, the noise transmitted to the power supply line because the power supply line to the positive electrode part is connected at the shortest distance, Conductive noise that is noise transmitted from the power supply line and radiation noise radiated from the power supply line to the air can be minimized, and the influence of noise on the sample liquid detection unit 5 of the capillary electrophoresis apparatus can be prevented. There is an advantage.

  In order to detect the migrating sample solution, the sample solution and the fluorescent material are modified before the sample solution is introduced into the capillary 2, so that the sample solution flowing in the capillary 2 is sampled. The detection unit 5 can detect fluorescence. In the sample liquid detection unit 5, the fluorescence of the fluorescent material modified in the sample liquid can be converted into an electric signal by a photodiode and viewed as a detection result. In the apparatus shown in FIG. 1, Cy5 (a red fluorescent dye has a maximum absorption wavelength of 650 nm and a maximum fluorescence wavelength of 670 nm) is used as the fluorescent dye, and therefore a semiconductor laser of 630 nm is used as the excitation light source. It has been broken. This device can detect fluorescent dyes in various wavelength regions by selecting an excitation light source and a filter suitable for the fluorescent dye.

  As described above, in the capillary electrophoresis apparatus of the present embodiment, the capillary holding unit 4 is located at the uppermost stage of the housing 1, and the sample solution detection unit 5, the temperature control unit 6, and the sample solution transport unit 7 are disposed below. Therefore, the replacement work of the capillary 2 that is easy to break and very difficult to handle can be performed very easily.

  Next, the configuration of the capillary holding unit 4, the temperature control unit 6, and the sample liquid detection unit 5 will be described. 2 and 3 are a top view and a side sectional view of the temperature control unit 6 with the capillary holding unit 4 attached thereto.

  In the figure, the capillary holding part 4 is composed of two plates, and a groove having the same width as that of the capillary 2 is attached to the lower plate, and the capillary 2 is placed in the groove to be easily sandwiched. The capillary 2 can be positioned and held. The groove in which the capillary 2 is fitted may be formed on either of the two plates. The material of the plate 2 is preferably made of metal such as aluminum or cast iron, which has a good heat transfer rate that allows easy transmission of heat from the temperature control unit, but discharge occurs inside the apparatus because a high voltage is applied during electrophoresis. In order to prevent this, resin-made ABS (acetonitrile, butadiene, styrene) resin, acrylic, polycarbonate, etc. are used, the shape is rectangular, the longitudinal direction with a groove to hold the capillary tube is 85 mm, and other directions The size of 55 mm, the thickness of the two plates being 2 mm, and a thickness sufficient to hold the capillary tube can be used.

  In FIG. 3, when the capillary holder 4 is installed on the temperature controller 6, the Peltier element 14 of the temperature controller 6 is pressed against the plate of the capillary holder 4 by the compression spring 10. For this reason, the temperature control of heating and cooling can be efficiently performed by the Peltier element 14. Further, the casing of the temperature control unit 6 is made of a heat insulating material, and this heat insulating material covers only the space including the sample liquid detection unit 5 below the capillary holding unit 4, so that a very small space is not covered. The temperature can be controlled efficiently.

  Heat that is heated or cooled by the Peltier element 14 is transmitted to the capillary holding part 4 that is in contact with the Peltier element 14 by heat transfer, and is further transferred to the inside of the capillary 2 that is in contact with the capillary holding part 4. The electrophoresis speed of the sample solution that is being electrophoresed by the heat transferred to the inside of the capillary 2 becomes slow when cooled, becomes faster when heated, and can be divided according to the molecular weight according to the speed difference from the electroosmotic flow. Is known. The sample liquid separated at the place where the capillary holder 4 and the Peltier element 14 are in contact with each other is subjected to electrophoresis while being separated, and is arranged downstream of the Peltier element 14 with respect to the direction of migration of the sample liquid. The sample liquid detection unit 5 is detected. The capillary holding unit 4 is in contact with the temperature control unit 6 on the upstream side of the sample liquid migration direction, and a part of the optical system of the sample liquid detection unit 5 is arranged on the downstream side. The sample detection unit 5 detects the fluorescence 12 by irradiating the excitation light 11 upward from a light source provided below the capillary holding unit 4.

  A part of the heat insulating material constituting the temperature control unit 6 is constituted by a transparent member 15 that transmits the excitation light 11, and focuses on the capillary 2 through the objective lens 13. The capillary holding part 4 irradiated with the excitation light 11 has a through hole 16 having a diameter of 6 mm or more with respect to the elliptical diameter (major axis 0.7 mm, minor axis 0.2 mm) of the excitation light 11. The excitation light that has passed through the capillary tube shears and spreads in a fan shape and is reflected by the holding plate 2 in the vicinity of the irradiation section because the curved surface of the capillary tube acts like a lens. Therefore, by making the opening diameter of the through hole larger than the light diameter of the excitation light in this way, the light spreading in a fan shape is not reflected to the detection unit installed in the same direction as the irradiation side. Therefore, detection noise can be reduced, and the detection limit of fluorescence detection can be increased, so that the amount of the sample to be detected can be reduced.

  According to the capillary holding part 4 configured as described above, a flexible capillary can be easily held straight by sandwiching the capillary 2 between two flat plates, The area where the detection is performed can be protected from trauma, and the attachment / detachment of the apparatus while being held by the hand is facilitated.

  Further, since the capillary 2 heats or cools only the portion where the capillary holding unit 4 and the Peltier element 14 are in contact with each other, the configuration of the temperature control unit 6 is reduced, and a small device can be manufactured. In addition, since only the portion where the Peltier element 14 is in contact is temperature-controlled, the temperature response speed is improved and temperature control with little temperature error is possible.

  Further, since the capillary holder 4 has a through-hole 16 in the portion irradiated with the excitation light 11 of the sample solution detector 5, the sample solution detector by autofluorescence of the capillary holder 4 and refraction of the light of the capillary 2 is provided. The influence of the background noise on 5 can be reduced.

  As described above, according to the present invention, when a capillary is exchanged or when a sample solution is installed in a main body, the operation can be easily performed, which is suitable for a capillary type electrophoresis apparatus.

The perspective view which shows the internal structure of the capillary electrophoresis apparatus in Example 1 of this invention. Plan view of capillary holding part constituting the capillary electrical device Cross-sectional view of the capillary holder Side view of a conventional capillary electrophoresis device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case 2 Capillary 3 Electrophoresis part 4 Capillary holding part 5 Sample liquid detection part 6 Temperature control part 7 Sample liquid conveyance part 8 High voltage power supply part 9 Intake pump 10 Compression spring 11 Excitation light 12 Fluorescence 13 Objective lens 14 Peltier element

Claims (10)

A housing having a lid that opens the top;
A capillary holding part that is detachably attached to the case from the upper part of the case opened by the lid, and that holds at least a portion of the capillary that undergoes electrophoresis horizontally;
An electrophoresis unit having electrodes for holding the both ends of the capillary and applying a voltage for performing the electrophoresis;
A sample solution holding part in which both ends of the capillary and the electrode are immersed,
A temperature control unit arranged below the capillary holding unit and performing temperature control of the capillary via the capillary holding unit;
A sample liquid detection unit that is disposed below the capillary holding unit and optically detects the state of electrophoresis performed in the capillary located above the capillary holding unit;
Capillary electrophoresis apparatus comprising: 2. The capillary electrophoresis apparatus according to claim 1, wherein the capillary holding part is composed of two plates, and a part of the capillary is held horizontally between the two plates. The capillary electrophoresis apparatus according to claim 2, wherein a groove in which the capillary is fitted is formed in at least one of the two plates of the capillary holding portion. The capillary electrophoresis apparatus according to claim 2, wherein the capillary holding part has a through hole at a position facing the sample liquid detecting part, and a capillary is disposed in the through hole. The capillary electrophoresis apparatus according to claim 4, wherein the through-hole has an opening larger than a diameter of irradiation light irradiated from the sample detection unit. 2. The capillary electricity according to claim 1, wherein a temperature control unit and a sample liquid detection unit are arranged in parallel below the capillary holding unit in order from the upstream side to the downstream side of electrophoresis. Electrophoresis device. The capillary electrophoresis apparatus according to claim 1, wherein the temperature control unit includes a Peltier element in contact with the capillary holding unit. 2. The capillary electrophoresis apparatus according to claim 1, wherein a high-voltage power source for performing electrophoresis is disposed below the positive electrode part of the electrophoresis part. The capillary electrophoresis apparatus according to claim 1, wherein the electrode of the electrophoresis unit is configured to be detachable from the housing. The sample solution holding part is held horizontally so that the capillaries and the electrodes are immersed from the opened upper surface, and further, the sample solution holding part is arranged in the outward direction of the side surface of the opened housing. 2. The capillary electrophoresis apparatus according to claim 1, wherein the capillary electrophoresis apparatus is configured to be slidable and detachable from the housing.

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