JPH01132952A - Electrophoresis apparatus - Google Patents

Abstract

PURPOSE:To make it possible to prevent the deactivation and the denaturation of a sample, by forming the surface of a cooling plate in a projecting surface, and bringing the surface and a film on which gel is attached into close contact. CONSTITUTION:A film 8 is mounted on a cooling plate 2, and a cap 10 is placed. Then, a curved part 9a of a pushing part compresses both parts of the film 8 to the plate 2 so as to fix both parts. At this time, the film 8 is in close contact with a projecting surface 2a of the cooling plate 2. Both end parts 8 and 8a are immersed in buffer liquid 5. Therefore, gel 7, which is supported with the film 8 is directly in contact with the buffer liquid 5, and an electric bridge for energization is not required. When a voltage is applied to an electrode line 6, the gel 7 is energized by the buffer liquid 5 directly, and electrophoresis is started. Since the gel 7 is uniformly conducted, an electric field in the gel 7 becomes uniform. Disturbance in electrophoresis pattern is eliminated. A cooling device 3 cools the plat 2 by the energization. Joule's heat, which is generated during the electrophoresis of the gel 7, is cooled. Therefore, the deactivation and the denaturation of a sample can be prevented beforehand.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to an electrophoresis apparatus, and particularly to a constant temperature electrophoresis apparatus that has a cooling device and does not use a battery case.

"Prior art and its problems" Electrophoresis is a method of analysis by applying a voltage to a charged sample. A typical embodiment of the electrophoresis method involves coating or casting a film-forming material inert to the sample, such as agar, cellulose acetate, starch, silica gel, or polyacrylamide, on a support such as glass or plastic film. to impregnate the electrophoresis carrier with buffer solution,
The sample to be analyzed is added onto this, and the electrophoresis carrier (
A DC voltage is applied to both ends of the gel (hereinafter referred to as gel).

Then, the charged component of the sample moves within the gel or on its surface depending on its charge, isoelectric point, molecular weight, etc. This movement speed varies depending on the properties of the components in the sample, so by applying a voltage for a certain period of time, an electrophoresis pattern in which each component is separated can be obtained.

In recent years, this electrophoresis method has been widely used in the field of biochemistry to analyze proteins that are physiologically active substances, and in the field of clinical testing to diagnose pathological conditions through analysis of body fluids such as blood and spinal fluid.

In sample analysis using the electrophoretic method described above, it is important to (1) prevent inactivation and denaturation of the sample during electrophoresis, and (2) reproducibility of the electrophoretic pattern.

First, the problem of (1) arises due to the deactivation and denaturation of the sample and the generated Joule heat. As mentioned above, electrophoresis is performed by applying a DC voltage to both ends of the gel and passing a current through the gel, but in recent years there has been a trend to apply higher voltages in order to shorten the electrophoresis time. The voltage reaches several kilovolts. For this reason, the generated Joule heat becomes large, and this heat can cause samples such as proteins to become inactivated or denatured, and if this happens, accurate sample analysis cannot be performed.

Further, factors affecting the reproducibility of (2) are that the temperature distribution in the gel is not uniform and that the electric field in the gel is disturbed. In order to make the temperature distribution in the gel uniform, the problem can be solved by uniformly cooling the gel. However, in order to make the electric field uniform, the voltage must be uniformly applied to the gel. Conventionally, as a means of applying voltage to the gel in a planar electrophoresis device, loose conductors such as carbon rods and platinum wires that do not easily cause electrolysis have been used. Gj solution, first, electricity is applied to the buffer solution, and then a salt bridge made of filter paper or porous sponge impregnated with the buffer solution is created between the buffer solution and the gel to create an electrical connection. Ta. However, with this method, it is very difficult to bring the filter paper or sponge into uniform contact with the gel surface, and the areas with poor contact are not sufficiently energized, which causes disturbances in the electric field in the gel, and as a result, the migration pattern changes. It exhibits a phenomenon commonly referred to as a waving pattern. Furthermore, since filter paper and sponge are consumable items, new ones must be prepared each time electrophoresis is performed, which tends to make operations complicated.

In order to improve this problem, an apparatus has been disclosed in which a gel is placed on an arcuate concave surface and both ends of the gel are brought into direct contact with a buffer solution. However, since the plate on which the gel is placed has an arcuate concave surface, it is structurally very difficult to cool this concave plate, and it is also inconvenient to handle, so it is virtually impossible to incorporate a cooling function.

``Object of the Invention'' An object of the present invention is to provide a constant temperature air phoresis device that is less likely to cause deactivation or denaturation of a sample and that can provide highly reproducible results without disrupting the electrophoresis pattern.

"Summary of the Invention" The present invention provides that the plate on which the gel is placed has a cooling function,
Since the plate surface has an arcuate convex surface, both ends of the gel placed on it directly touch the buffer solution in which the electrode rod is immersed, and the gel is electrically energized directly from the buffer solution. I'm doing it.

In this case, since the plate has an arcuate convex surface, a cooling mechanism can be easily incorporated. In addition, since the plate has a cooling function, the Joule heat generated during electrophoresis can be offset, so the sample will not be deactivated or denatured, and the gel will be cooled uniformly. This problem can be solved by making the heat capacity of the cooling plate sufficiently large compared to the Joule heat generated.

The surface of the cooling plate on which the gel is placed has an arcuate convex surface, and the gel placed on it is in close contact with the surface of the cooling plate, forming a curve, and both ends of the gel are directly connected to the buffer solution in which the electrode rod is immersed. Since the gel is in contact with the gel, electricity is applied directly to the gel from the buffer solution. Therefore, unlike in the past, there is no need for an electric bridge that electrically connects the buffer solution and the gel, and as a result, the gel is uniformly energized, the electric field in the gel is uniform, and the migration pattern is not disturbed. .

The plate on which the gel used in the present invention is placed is made of a material with good thermal conductivity such as aluminum or copper, and the surface is covered with an electrical insulator such as epoxy resin, fluorine resin, acrylic resin, or ceramic. This prevents the flow through the gel from flowing toward the plate.

The surface has an arcuate convex shape as described above. The radius of curvature can be increased arbitrarily as long as it does not impede operability.
The length is preferably equal to or less than the length of a commonly used gel in the migration direction. There is also a cooling device attached to the bottom of the second plate.

Although all known methods can be used as the cooling device used in the present invention, an electronic cooling device using a thermo module is preferably suitable.

The gel used in the present invention is usually held on a carrier made of a film such as polyester. Therefore, it is difficult to adhere such a gel to a plate as it is because the film is elastic. Therefore, a presser is required to hold it tightly against the plate.

This presser foot must be made of an electrically insulating elastic material; if it is not electrically insulating, there is a risk that the current flowing through the gel will short-circuit. Further, the shape is an arc along the convex surface of the plate, and has a radius of curvature slightly smaller than the plate surface, and by pressing this against the gel, the gel is brought into close contact with the plate by the elasticity of the presser foot. In addition, other shapes include a flat plate shape that is pressed by utilizing the elasticity generated when a long and thin flat elastic body is pressed and bent. Examples of the material for these elastic bodies include plastics such as polypropylene and hard polyethylene.

Although this presser foot can be provided independently from the main body of the electrophoresis device, it is preferably integrated with the lid of the electrophoresis device, and the presser foot works when the lid is closed.
It is desirable to have a mechanism that brings the gel into close contact with the plate.

[Examples] The present invention will be explained in more detail below with reference to illustrated examples.

FIG. 1 is a perspective view of an outline of an electrophoresis device according to the present invention, and FIG. 2 is a sectional view taken along the line I-I', in which a cooling plate is fixed to the center of the main body case l.

The cooling plate 2 is made of a material with good thermal conductivity such as aluminum or copper, and the surface 2a is formed into an arcuate convex surface, and is made of an electrical insulator such as epoxy resin, acrylic resin, fluororesin, or ceramic. Covered.

3 is a cooling device such as a thermo module provided at the lower part of the cooling plate 2, and is designed to efficiently cool the cooling plate 2. Reference numeral 4 denotes a container containing a buffer solution 5, which is disposed along both edges of the cooling plate 20 slightly below.

Reference numeral 6 denotes an electrode rod that is immersed in the buffer solution 5 and placed inside the container 4, and is made of a conductor such as a carbon rod or a platinum wire. 7 is a gel, and a film 8 of polyester or the like
This film 8 is provided on the cooling plate 20.
It is placed in close contact with the surface 2a by a presser 9. A pair of presser feet 9 are attached to the back side of the lid 10 of the main body case 1, and are made of an electrically insulating elastic material and have a curved portion 9a, and the radius of curvature of this curved portion is the same as that of the convex surface of the cooling plate 2. The radius of curvature is set slightly smaller than the radius of curvature of 2a.

The electrophoresis apparatus according to the present invention is constructed as described above, and when the film 8 is placed on the cooling plate 2 and the lid IO is closed, the curved part 9a of the presser foot pushes both measuring parts of the film 8 onto the cooling plate 2. Can be fixed by crimping. At this time, the film 8 is in close contact with the convex surface 2a of the cooling plate, and both ends 8
a is immersed in the buffer solution 5. Therefore, film 8
The gel 7 supported on the buffer solution 5 comes into direct contact with the buffer solution 5, and a conventional electrical container is not required.

When a voltage is applied to the electrode wire 6, the gel 7 is energized directly from the buffer solution 5 and electrophoresis is started. In this case, the gel 7 is energized uniformly, so the electric field in the gel becomes uniform. Disturbances in migration patterns are eliminated.

The cooling device 3 has the function of cooling the cooling plate 2 by applying electricity, and as a result cools the Joule heat generated during i'li aerophoresis of the gel 7, thereby preventing deactivation and denaturation of the sample, It becomes possible to perform accurate sample analysis.

[Effects of the Invention] As explained above, according to the present invention, the surface of the cooling plate is formed into an arcuate convex surface, so when a film on which gel is adhered is closely attached to the convex surface, both ends of the gel are buffered. It is immersed in a liquid and electrically connected directly to the gel, eliminating the need for a conventional battery case, and has excellent effects such as applying a uniform voltage to the gel and preventing disturbances in the electric field within the gel. .

In addition, a cooling device is installed at the bottom of the cooling plate, which quickly removes Joule heat generated during electrophoresis and prevents sample deactivation and denaturation due to heat. It is also possible to shorten the time.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along line 1-1' in FIG. 1, and FIG. 3 is a schematic perspective view of a conventional example. l... Main body case 2... Cooling plate 3...
Cooling device 4... Container 5... Buffer solution 6... Electrode rod 7... Gel
8...Film 9...Holder lO・
... Lid 11 ... Shiobashi Patent Applicant Biomate Co., Ltd. Figure 1 Figure 2

Claims (3)

[Claims] (1) The surface of the plate on which the electrophoretic carrier is placed is an arcuate convex surface so as to be in direct contact with the buffer solution that applies voltage at both ends of the electrophoretic carrier placed on it, and the plate is equipped with a cooling device. A constant temperature electrophoresis apparatus comprising: (2) Claim (1) characterized in that the electrophoretic carrier is provided with an electrophoretic carrier presser made of an electrically insulating elastic material so that the electrophoretic carrier placed on the cooling plate is brought into close contact with the cooling plate. thermostatic electrophoresis device. (3) A thermostatic electrophoresis apparatus according to claim (2), characterized in that a presser for the electrophoresis carrier is attached to a lid of the electrophoresis apparatus.