JPH11337521A - Member for electrophoresis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an influence of an ion component formed by electrolysis in a migration buffer sump until analysis of a test sample solution is completed and keep a constant migration speed of an electrophoresis solution. SOLUTION: This member for electrophoresis applies an appropriate voltage to each of a reservoir 1, a liquid test sample introducing opening 2, a liquid test sample discharge outlet 3 and a migration solution discharge outlet 4. Migration is made to a liquid test sample, which exists at intersection of a liquid test sample introducing passage 5 and a separating passage 6, toward the migration solution discharge outlet 4 and the liquid test sample develops to the separating passage 6. A capacity of the reservoir 1 is made large sufficiently and the member for electrophoresis has a structure wherein a part of a position of an electrode 7a is formed on upper surface of an interior of the reservoir 1. Accordingly, the influence of an ion component formed by electrolysis at the reservoir 1 is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophoresis member used in an electrophoresis apparatus used for analyzing very small amounts of proteins, nucleic acids, and the like at high speed and with high resolution.

[0002]

2. Description of the Related Art In an electrophoresis apparatus using a glass capillary, two electrophoresis buffer reservoirs in which both ends of the glass capillary are filled with an electrophoresis buffer are connected to both ends of the glass capillary and electrodes for applying a high voltage connected to a high voltage power supply. Is applied, and a high voltage is applied to both ends of the glass capillary, whereby the analyte is developed in the capillary and detected by the detector. However, in an electrophoresis apparatus using a glass capillary, the outer diameter of the glass capillary is as thin as about 10 to several tens of μm and is easily broken, so that the handling when the user replaces the glass capillary is not easy, and the apparatus can be downsized. There was no problem.

Therefore, a plate-like capillary member formed by joining two substrates has been proposed. FIG.
1 shows an electrophoresis member using a conventional plate-shaped capillary.

[0004] Using photo fabrication technology,
Analysis channel groove 5 and sample injection channel groove 3 that intersect each other
And a substrate 1b on which migration buffer reservoirs 7 located at both ends of the grooves 5 and 3 are formed.
Are joined to form a plate-like capillary electrophoresis member.

[0005] Then, a potential difference is applied to the two electrophoresis buffer reservoirs 7, the electrophoresis liquid mixed with the liquid sample is developed in the analysis channel groove 5, and light is irradiated to perform analysis.

[0006]

However, in the above prior art, depending on the type of the electrophoresis solution, the electrophoresis solution in the electrophoresis buffer reservoir is ionized to such an extent that the analysis accuracy is deteriorated by the time when the analysis of the liquid sample solution is completed. As a result, the sample solution cannot be migrated at a constant speed in the flow channel for analysis 5 due to the influence of ionic components formed by electrolysis in the electrophoresis buffer reservoir, and the migration speed changes. Reproducibility of analysis when the same sample is analyzed under the same conditions is lost, and accurate measurement cannot be performed.

For example, when a migration solution having a high electric conductivity such as a phosphate buffer is used, when a migration current of 10 μA flows, 10 ^-11 mol of ions are newly generated per second. If the volume of the electrophoresis buffer is 1 μl, the concentration becomes 10 ⁻⁴ M in 10 seconds, which has a considerable effect.

The present invention has been devised to solve the above-mentioned problems, and suppresses the influence of ionic components formed by electrolysis in a migration buffer reservoir until the analysis of a sample solution is completed. It is an object of the present invention to provide an electrophoresis member capable of keeping the electrophoresis speed constant.

[0009]

In order to achieve the above object, an electrophoresis member according to the present invention is formed such that at least two flow paths intersect inside a predetermined substrate. At one end of each of the flow paths, a reservoir for storing an electrophoresis running solution or a sample is formed.The flow path and the reservoir are filled with the electrophoresis running fluid, and by applying a potential difference to both ends of each flow path, the sample of the electrophoresis is removed. In a member that performs movement or separation analysis, at least one of the reservoirs in at least one of the flow passages has an electrophoresis solution in an amount that can sufficiently suppress fluctuations in ion concentration in the reservoir even when electrophoresis is performed for a required time. It is characterized by a structure that can be stored.

[0010] In another configuration, a reservoir for storing an amount of the electrophoresis running liquid capable of keeping the fluctuation of the ion concentration sufficiently small even when electrophoresed for a required time is provided in an electrophoresis running fluid reservoir added to the outside. It is characterized by being.

Furthermore, in order to secure a sufficient amount of the electrophoresis running solution, a part of the flow path is used as a reservoir for the electrophoresis running solution in place of the reservoir.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a view showing the structure of the electrophoretic member of the present invention.

1 is a reservoir for securing a sufficient amount of electrophoresis running liquid, 2 is a liquid sample inlet, 3 is a liquid sample outlet, 4
Denotes an electrophoresis solution outlet, 5 denotes a sample liquid introduction channel, 6 denotes a separation channel for separating a liquid sample, and 7a to 7d denote electrodes.

The electrophoresis member is constituted by laminating two substrates a and b made of quartz, glass, Si, plastic or the like. On the substrate a side, a reservoir 1, a liquid sample inlet 2, a liquid sample Outlet 3, electrophoresis running fluid outlet 4, electrode 7
a to 7b are formed, and a sample liquid introduction channel 5 and a separation channel 6 are formed on the substrate b side.

The electrodes 7a to 7d are formed by depositing Cr to a thickness of about 200 to 300 angstroms by sputtering or the like, and then forming Au to a thickness of about 2000 to 3000 angstroms. As shown in the figure, the reservoir 1 has a volume required to secure a sufficient amount of the electrophoresis running solution, and the electrode 7a is not formed on the entire surface of the reservoir 1, but is formed inside the reservoir 1. It has a small area up to a predetermined depth.

The electrodes 7b to 7d are not formed on the entire inner surfaces of the through holes of the liquid sample outlet 3, the liquid sample inlet 2, and the electrophoretic solution outlet 4, but are formed only on a part of the upper inner surface. ing.

In order to perform electrophoresis, a voltage having an appropriate relationship is applied to each of the reservoir 1, the liquid sample inlet 2, the liquid sample outlet 3, and the electrophoretic solution outlet 4, and the sample liquid introduction flow path 5 The liquid sample present at the intersection of the separation channel 6 and the separation channel 6 is migrated in the direction of the electrophoretic solution discharge port 4 and is developed in the separation channel 6. Then, for example, the detection light is irradiated from above onto the liquid sample developed in the separation channel 6, and the transmitted light is detected by a sensor for analysis.

In the present invention, since the volume of the reservoir 1 is made sufficiently large and the position of the electrode 7a is partially formed on the inner upper surface of the reservoir 1, it is necessary to completely ionize the electrophoresis running solution by electrolysis. It takes a considerable amount of time, and since the electrode 7a is formed small at a location away from the entrance of the separation flow path 6, a large amount of ions due to electrolysis do not flow into the separation flow path 6 at one time. The influence of the ions formed by the decomposition becomes very small in the analysis flow path (separation flow path 6), and the migration speed of the electrophoresis liquid can be kept constant.

Next, FIG. 2 shows a structure in which a part of the flow path is used as a reservoir for the electrophoresis liquid so as to be hardly affected by the ionic components formed by electrolysis in the analysis flow path.

The same components as those in FIG. 1 are denoted by the same reference numerals. The electrophoresis liquid inlet 1a has a normal volume, but the electrophoresis liquid inlet channel 1 having a large cross section is connected to the electrophoresis liquid inlet 1a. Is connected to the small separation channel 6, and the volume of the electrophoresis liquid introduction channel 17 is preferably equal to or larger than the volume of the separation channel 6 up to the detection unit.

For example, the electrophoresis running liquid introduction channel 17 has a width of 500 μm.
m, and a depth of 20 μm.
It is composed of 0 μm and a depth of 20 μm.

With such a configuration, the electrophoresis liquid introduction channel 17 serves as a buffer, and the electrophoresis liquid inlet 1a
It takes a considerable time for the ions generated in the above to reach the separation channel 6 by the electroosmotic flow, and since the electrode 7e is formed small and far away from the electrophoresis solution introduction channel 17, the electrode 7e The ions do not flow into the separation channel 6 in large quantities at one time, and the influence of ions formed by electrolysis is very small in the analysis channel (separation channel 6).

FIG. 3 shows that an additional electrophoresis liquid reservoir is formed outside the reservoir of the electrophoresis member formed on the substrate.
This shows a structure in which the influence of ion components formed by electrolysis in the reservoir is hardly affected in the analysis channel.

FIG. 4 is a detailed view of the part A in FIG.
4A shows a top view of the portion A, and FIG. 4B shows a side view.

The external reservoir 10 is formed above the through-hole 9 and has a volume for storing an amount of the electrophoresis running fluid capable of keeping the fluctuation of the ion concentration in the reservoir 10 sufficiently small. The external reservoir 10 presses, for example, silicon rubber or the like against a substrate and adheres with an adhesive or the like. The electrode 8 is formed apart from the through hole 9, and the through hole 9 is connected to the separation channel 6.

In this manner, for the same reason as in the above embodiment, even if the electrophoresis is performed for the time required for the analysis, the influence of ions formed by the electrolysis can be caused in the analysis channel (separation channel). In 6), the size becomes very small, and the electrophoresis speed of the electrophoresis solution can be kept constant.

[0028]

According to the present invention, the electrophoresis member is provided with a reservoir having a sufficient volume and an electrophoresis liquid introduction channel for storing the electrophoresis liquid, and the electrophoresis is carried out for analysis. The analysis reproducibility is improved by making it difficult for the electrophoresis liquid in the analysis flow path to be affected by the ionic components formed by electrolysis in the reservoir within the time required for the analysis.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing another configuration of the present invention.

FIG. 3 is a diagram showing another embodiment of the present invention.

FIG. 4 is an enlarged view of a portion A in FIG. 3;

FIG. 5 is a view showing a configuration of a conventional electrophoretic member.

Claims (3)

[Claims] At least two flow paths are formed inside a predetermined substrate so as to intersect with each other, and at one end of each of the flow paths, a reservoir for storing an electrophoretic solution or a sample is formed. A channel and a reservoir are filled with an electrophoresis liquid, and a potential difference is applied to both ends of each channel, so that at least one of the reservoirs of at least one channel is necessary in a member for moving a sample by electrophoresis or performing separation analysis. An electrophoretic member having a structure capable of storing an amount of an electrophoresis running solution capable of sufficiently suppressing fluctuations in ion concentration in a reservoir even when electrophoresis is performed for a short period of time. 2. The electrophoretic member according to claim 1, wherein a reservoir for storing an amount of the electrophoresis running liquid capable of keeping the fluctuation of the ion concentration sufficiently small even when the electrophoresis is performed for a required time is added to the outside. A member for electrophoresis, wherein the member is an electrophoresis liquid reservoir. 3. At least two channels are formed inside a predetermined substrate so as to intersect with each other, and at one end of each channel, a reservoir for storing an electrophoretic solution or a sample is formed. By filling the flow path and the reservoir with the electrophoresis running solution and applying a potential difference to both ends of each flow path, the member that performs electrophoretic sample movement and separation analysis can maintain the ion concentration even when electrophoresed for the required time. An electrophoresis member characterized in that a part of a flow path is used as an electrophoresis liquid reservoir in order to secure a sufficient amount of electrophoresis liquid in which fluctuations can be sufficiently suppressed.