JP2004325304A - Columnar structure for electrophoresis device and electrophoresis device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-priced columnar structure and an electrophoresis device. <P>SOLUTION: The columnar structure 1 has a structure in which a plastic substrate 2 and many columnar projections 3 are integrated, and is replicated by a forming method using a mold. The electrophoresis device has a minute flow path formed by bonding the columnar structure 1 and a transparent substrate together. A sample is allowed to path through the minute flow path and to be separated by electrophoresis. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a columnar structure provided with a large number of columnar projections, and an electrophoretic device having the columnar structure.
[0002]
[Prior art]
2. Description of the Related Art In recent years, attention has been focused on analysis techniques and separation techniques for DNA and RNA, which are one field of biotechnology. Conventionally, as a DNA separation means, an electrophoresis method using a mesh gel or a polymer has been known.
Recently, there has been reported a technique in which a columnar structure in which fine columns are formed on a silicon substrate is provided on a silicon substrate using a semiconductor manufacturing process, and the columnar structure is used instead of gel or polymer (for example, Patent Document 1). reference).
[0003]
[Patent Document 1]
JP-A-4-21232 (pages 4, 5; FIGS. 7, 8)
[0004]
[Problems to be solved by the invention]
In particular, when the columnar structure is used as a filter of an electrophoresis device, if the sample is clogged or the column is lost, it is necessary to replace the columnar structure with a new one. That is, from the viewpoint of consumables, it is required that mass production be possible and that the cost be low.
The conventional silicon columnar structure has a problem that the manufacturing cost is high because it is manufactured using a number of processes such as patterning, etching, and oxidation of resist.
[0005]
The present invention provides an inexpensive columnar structure and an electrophoretic device.
[0006]
[Means for Solving the Problems]
(1) The columnar structure for an electrophoretic device according to claim 1 is characterized in that a plastic substrate and a number of columnar projections have an integral structure and are replicated by a molding method using a mold.
In the columnar structure according to claim 1, the gap between the columnar projections is preferably in a range of 5 nm to 10 μm.
[0007]
(2) In the columnar structure for an electrophoretic device described above, the mold uses a columnar structure formed by forming a large number of columnar protrusions on a silicon substrate by photolithography and thermally oxidizing the surface of the columnar protrusions as a matrix. Preferably, it is manufactured by electroplating or electroless plating.
The mold is a columnar structure formed by forming a large number of columnar protrusions on a silicon substrate by photolithography, thermally oxidizing the surface of the columnar protrusions, and forming a polycrystalline silicon film on the surface of the oxidized columnar protrusions. Is preferably manufactured by electroplating or electroless plating.
Also, the mold forms a large number of columnar projections on the silicon substrate by photolithography, thermally oxidizes the surface of the columnar projections, forms a polycrystalline silicon film on the surface of the oxidized columnar projections, and forms the polycrystalline silicon. The film is preferably thermally oxidized, and is preferably manufactured by electroplating or electroless plating using a columnar structure formed by depositing polycrystalline silicon on the oxidized polycrystalline silicon film as a matrix.
Furthermore, the mold is formed by forming a large number of columnar projections on a silicon substrate by photolithography, and using a columnar structure formed by depositing polycrystalline silicon on the surface of the columnar projections as a matrix, by electroplating or electroless plating. It is characterized by being manufactured
(3) In the micro mold according to claim 7, a large number of columnar projections are formed on a silicon substrate by photolithography, and a columnar structure formed by thermally oxidizing the surface of the columnar projections is used as a matrix for electroplating or electroless. It is characterized by being manufactured by plating.
The micro mold according to claim 8 is formed by forming a large number of columnar projections on a silicon substrate by photolithography, thermally oxidizing the surface of the columnar projections, and forming a polycrystalline silicon film on the surface of the oxidized columnar projections. It is characterized by being manufactured by electroplating or electroless plating using the columnar structure as a matrix.
The micro mold according to claim 9 forms a large number of columnar projections on a silicon substrate by photolithography, thermally oxidizes the surface of the columnar projections, and forms a polycrystalline silicon film on the surface of the oxidized columnar projections. It is manufactured by electroplating or electroless plating using a columnar structure formed by thermally oxidizing a polycrystalline silicon film and depositing polycrystalline silicon on the oxidized polycrystalline silicon film as a matrix. .
According to a tenth aspect of the present invention, there is provided the micro mold, wherein a large number of columnar projections are formed on a silicon substrate by photolithography, and a columnar structure formed by depositing polycrystalline silicon on the surface of the columnar projections is used as a matrix for electroplating or non-plating. (4) The electrophoretic device according to the eleventh aspect, characterized in that the electrophoretic device is manufactured by electroplating, and the columnar structure according to the first to sixth aspects is transparently joined to and contacted with the tips of a number of columnar projections. It has a minute flow path composed of a substrate, and a sample is passed through the minute flow path by electrophoresis to be separated.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a columnar structure and an electrophoretic device according to the present invention will be described with reference to the drawings.
(1st Embodiment)-Columnar structure-
FIG. 1 is a partial perspective view schematically showing the structure of the columnar structure according to the first embodiment of the present invention. In the figure, the front A surface is a cut surface of the columnar structure 1.
[0010]
The columnar structure 1 is composed of a plastic substrate 2 and columnar projections (pillars) 3, and as shown by plane A, the plastic substrate 2 and the pillars 3 are an integral structure. A pillar array 4 in which a large number of pillars 3 are arranged stands in the entire concave portion 5 of the plastic substrate 2. However, in order to make the state of the pillar array 4 easy to see, the pillar array in the middle part of the concave portion 5 is not shown.
[0011]
The height of the pillar 3 is usually equal to the depth of the recess 5. In addition, the arrangement pitch of the pillars 3 and the gap between the pillars 3 are often constant, but may differ depending on the location as described later.
[0012]
First, a manufacturing process of the columnar structure 1 made of plastic will be described. The manufacturing process is roughly divided into a manufacturing process of the die and a manufacturing process of the columnar structure 1.
FIG. 2 is a partial cross-sectional view for explaining a manufacturing process of the mold. However, the illustration of the pillar 13 existing in the middle part of the pillar array 14 is omitted.
[0013]
FIG. 2A shows a matrix 11 for manufacturing the columnar structure 1. The matrix 11 is made of, for example, a silicon material by using known micromachining. On the silicon substrate 12, a pillar array 14 including a number of pillars 13 is formed. The structure and manufacturing process of the matrix 11 will be described later in detail.
FIG. 2B shows a state where the base film 21 is formed on the surface of the matrix 11. Using Ti and Pd as base metals, the base film 21 is formed continuously by a sputtering method. The thicknesses of Ti and Pd are very thin, 100 nm and 20 nm, respectively.
[0014]
FIG. 2C shows a mold 20 manufactured by depositing a thick Ni material 22 on the base film 21 by electroplating using the conductivity of the base film 21. The composition of the plating solution, nickel sulfamate _{(Ni (NH 2 SO 3)} · 4H 2 O) to about 1.4M and nickel bromide (NiBr ₂₎ about 0.014M boric acid _(H 3 BO ₃₎ about 0. A surfactant (pit prevention agent) or the like is added in an appropriate amount to a 5M mixed solution. The processing conditions are a liquid temperature of 50 ° C. and a current density of 0.1 A / dm ² , and the processing time is set in consideration of the Ni deposition rate of about 1.2 μm / hr.
[0015]
Further, as a method of manufacturing the mold 20 by depositing the Ni material 22, an electroless plating method can be used. According to this method, precipitates are deposited without applying an electric field, and thus are free from electric field concentration depending on the shape of the matrix, and have the advantage that Ni is deposited uniformly in the gaps between the pillars 3.
In the case of electroless plating, the composition of the plating solution is about 0.1 M of nickel sulfate (NiSO ₄ ) · 6H ₂ O and about 0.2 M of sodium hypophosphite (NaH ₂ PO ₂ ) · H ₂ O) and an organic acid. It is a mixture of salts and the like. The processing conditions are started from a liquid temperature of 60 ° C., raised to 90 ° C. in about 1 hour, and then maintained at 90 ° C. The processing time is set in consideration of the Ni deposition rate of about 12 μm / hr.
[0016]
FIG. 2D shows a state in which the silicon mother die 11 shown in FIG. 2C has been dissolved and removed, leaving only the mold 20. As an etching solution for dissolving the matrix 11, an aqueous solution of TMAH (tetramethylammonium hydroxide) having a concentration of 15% is used. The processing conditions are set such that the sample is immersed in a TMAH aqueous solution at a liquid temperature of 80 ° C., and the processing time is set in consideration of a dissolution rate (etching rate) of 30 to 40 μm / hr.
Note that a KOH (potassium hydroxide) aqueous solution can be used as the etching solution.
[0017]
The columnar structure 1 is molded by using the mold 20 manufactured as described above.
As a molding method of a plastic material in a molten or fluidized state, there are injection molding, compression molding, extrusion molding, ultraviolet curing and the like. In particular, injection molding is more suitable for processing high-precision parts having complicated shapes than other molding methods, and is also excellent in dimensional stability of parts. Further, the current injection molding machine is automated in production, and can be mass-produced.
[0018]
Resin materials used for injection molding include thermoplastic resins such as PMMA (polymethyl methacrylate), PS (polystyrene), ABS resin, PC (polycarbonate), PET (polyethylene terephthalate), phenolic resin, unsaturated polyester resin, There is a thermosetting resin such as an epoxy resin.
[0019]
The columnar structure 1 of the present embodiment uses a commercially available injection molding machine to mold the mold 20 in which PMMA heated to 170 to 270 ° C. is maintained at 50 ° C. at an injection pressure of 5 × 10 ⁷ Pa. Manufactured by injecting into a cavity. The columnar structure 1 is kept warm for a predetermined time after injection, and is taken out of the mold after being cooled. With this simple operation, the columnar structure 1 is manufactured. The columnar structure 1 has, of course, the same shape as the matrix 11. The number of columnar structures 1 that can be molded from one mold 20 (i.e., the life of the mold) depends on the diameter of the pillar 3, but is 100 to 1000.
[0020]
Subsequently, the structure and manufacturing process of the matrix 11, that is, the columnar structure 11 will be described with reference to FIGS.
FIG. 3 is a partial perspective view schematically showing a matrix structure for manufacturing the columnar structure according to the first embodiment of the present invention. FIG. 4 is a partial cross-sectional view showing a manufacturing process of the matrix shown in FIG.
[0021]
In FIG. 3, the matrix 11, that is, the columnar structure 11 includes a silicon substrate 12 and columnar protrusions 13, and the silicon substrate 12 and the pillar 13 are an integral structure. A pillar array 14 in which a large number of pillars 3 are arranged is formed in a concave portion 15 of a silicon substrate 12. The height of the pillar 13 is usually equal to the depth of the recess 15. In addition, the arrangement pitch of the pillars 13 and the gap between the pillars 13 are often constant, but may differ depending on the location as described later.
[0022]
From the viewpoint of the material, the silicon substrate 12 includes a silicon base material 12b, a silicon oxide layer 111, and a polycrystalline silicon film 112 in this order from the inside toward the surface. The pillar 13 has a material configuration in which a silicon oxide layer 111 is formed inside and a polycrystalline silicon film 112 is formed outside the silicon oxide layer 111. However, when the pillar 13 is thick, the material may have a structure in which silicon is present at the central portion, similarly to the silicon substrate 12. In any case, the substrate surface 12a, the bottom surface of the concave portion 15, the side surface of the concave portion 15, and the surface 13a of the pillar 13 are all polycrystalline silicon films 112.
[0023]
Here, the manufacturing process of the columnar structure 11 will be described with reference to FIG. FIG. 4 is a partial cross-sectional view for explaining a manufacturing procedure of the columnar structure, and is a view cut along a plane passing through the center axis of each pillar. The manufacturing process proceeds in order from (a) to (f). Since the material and volume of the pillar 13 change as the process proceeds, the pillar in each process is represented by reference numerals 13b to 13f.
[0024]
FIG. 4A shows a state in which the shape to be the pillar array 14 is patterned on the photoresist film 100 applied on the silicon substrate 12.
FIG. 4B shows a state of a pillar when the silicon substrate 12 is etched by inductively coupled plasma-reactive ion etching (ICP-RIE). For example, when the etching depth is 10 μm, the diameter of each pillar 13b is 2 μm, the height of each pillar 13b is 10 μm, and the interval between the pillars 13b, that is, the arrangement pitch is 4 μm.
[0025]
In the ICP-RIE, a sample is etched under a relatively low pressure of 0.05 to 1 Pa using a chemical reaction between ions of a process gas in a high-density plasma and the sample surface. High etching process is possible. An oxidizing gas such as CCl ₂ F ₂ or CF ₄ is used as the process gas.
[0026]
FIG. 4C shows a state of the pillar 13c on which the silicon oxide layer 111 has been formed by thermal oxidation. Examples of the thermal oxidation include dry oxidation using O ₂ gas and steam oxidation using steam or a mixed gas of H ₂ O and O ₂ . When thermal oxidation is performed at 1050 ° C. for 10 hours, the silicon oxide has a thickness of 2 μm, so that all the pillars 13c become silicon oxide, and volume expansion occurs. The silicon oxide may be formed by an oxidation method other than thermal oxidation, for example, plasma oxidation for ionizing O ₂ gas or anodic oxidation using an ethylene glycol solution. Further, for example, an oxide may be deposited on the pillar 13b by using a sputtering method in which an Ar ion is irradiated to an oxide target.
[0027]
FIG. 4D shows a state of a pillar 13d in which a polycrystalline silicon film 112a is deposited to a thickness of 200 nm by LPCVD (low pressure chemical vapor deposition).
LPCVD is a film formation method in which a sample is heated under a reduced pressure of 10 to 10 ³ Pa, and a film is formed on the sample surface by a gas phase chemical reaction using thermal energy. This method has an advantage that the film can be deposited easily and a uniform film thickness can be obtained. In forming polycrystalline silicon, SiCl ₄ + H ₂ or SiH ₄ is used as a process gas.
[0028]
FIG. 4E shows a state of the pillar 13e in which the polycrystalline silicon film 112a is oxidized by the second thermal oxidation at 1050 ° C. for 2 hours, and the silicon oxide layer 111 is additionally formed.
[0029]
FIG. 4F shows a state of the pillar 13f in which the polycrystalline silicon film 112 is deposited on the surface of the pillar 13e of FIG. This state is the same as that shown in FIG.
[0030]
Next, adjustment of the gap between the pillars 13 will be described. The gap is accurately adjusted by controlling the volume expansion of the pillar 13 due to thermal oxidation and controlling the film thickness of the polycrystalline silicon films 112 and 112a at the time of film formation.
According to the theory of thermal oxidation, 44% of the volume of silicon oxide corresponds to the volume of silicon before oxidation. Therefore, if the radius of the pillar 13c after the thermal oxidation is Rc and the radius of the pillar 13b before the thermal oxidation is Rb, there is a relationship of Expression 1.
(Equation 1)
Rc ³ = Rb ³ /0.44 (1)
However, according to the thermal oxidation experiment, the relationship of Expression 2 is established. Therefore, in this embodiment, Expression 2 is used.
(Equation 2)
Rc ³ = Rb ³ /0.55 (2)
[0031]
When the polycrystalline silicon film is thermally oxidized, the polycrystalline silicon film is extremely thin, so that a planar approximation holds with respect to Equation (1). That is, assuming that the thickness of the polycrystalline silicon film before thermal oxidation is t1 and the thickness after thermal oxidation is t2, the relationship of Equation 3 holds. Equation 3 has been confirmed to be compatible with experimental values.
[Equation 3]
t2 = t1 / 0.44 (3)
[0032]
If Equations 2 and 3 are applied to the setting of the thermal oxidation conditions, the volume expansion of the pillar 3 can be controlled. Also, the amount of increase in the diameter of the pillar 13 can be controlled by controlling the film thickness of polycrystalline silicon using LPCVD. In polycrystalline silicon film formation using LPCVD, since the film thickness can be controlled with an accuracy of 1 nm, the gap between the pillars 3 can be controlled with an accuracy of 1 nm.
[0033]
For example, in FIGS. 4B and 4C, since the diameter of the pillar 3b is 2 μm, if thermal oxidation is performed completely, the diameter of the pillar 13c is 2.44 μm from Equation 2. In FIGS. 4D and 4E, the diameter of the pillar 13d on which the polycrystalline silicon film 112a is deposited to 200 nm is 2.84 μm. .35 μm. The polycrystalline silicon film 112a having a thickness of 200 nm can be completely oxidized under a thermal oxidation condition of 1050 ° C. × 1.5 hours. However, in order to achieve complete oxidation, a thermal oxidation of 1050 ° C. × 2 hours is performed. You have selected a condition.
[0034]
However, when the polycrystalline silicon film is formed thick at a time, the accuracy of controlling the film thickness is reduced. Also, during thermal oxidation, the oxidation rate decreases as the inside of the film is increased. Therefore, when the polycrystalline silicon film is formed to be relatively thin and thermal oxidation is performed, the film thickness accuracy is improved and the oxidation rate is increased. By repeating the polycrystalline silicon film formation and thermal oxidation, the accuracy of the gap G between the pillars 13 is also improved, and the efficiency of the entire process is increased.
[0035]
By repeating the steps of FIG. 4D and FIG. 4E, for example, if the second oxidation is performed after forming a polycrystalline silicon film having a thickness of 80 nm, the diameter of the pillar 13e is reduced from 3.35 μm. Increase to 3.71 μm. In the step (b), the pitch between the pillars 13b is 4 μm, so that the gap between the pillars 13e is 0.29 μm.
[0036]
In the step of FIG. 4F, a polycrystalline silicon film 112 is formed on the outermost surface of the pillar 13f. This polycrystalline silicon film 112 is not subjected to thermal oxidation. For example, if the thickness of the polycrystalline silicon film 112 is 50 nm, the diameter of the pillar 13f is 3.81 μm, and the gap G between the pillars 13f is 0.19 μm.
[0037]
By manufacturing the columnar structure 11 using the above-described manufacturing method, a final gap G between the pillars 13 can be formed with an accuracy of 1 nm.
[0038]
Note that the above-described manufacturing process may be simplified and completed in the process of FIG. If the accuracy of the gap G between the pillars 13 is not strictly determined, the process may be completed in the step of FIG. Alternatively, the steps of FIGS. 4C to 4E may be omitted, and the polycrystalline silicon film 112 may be formed directly on the non-oxidized pillar 13b of FIG. In these simplified manufacturing processes, the manufacturing cost of the matrix 11 is reduced, but on the other hand, the dimensional accuracy of the mold 20 is roughened and the gap between the pillars 3 of the columnar structure 1 is reduced according to the simplification. The accuracy is also rough.
[0039]
(Second embodiment)-Electrophoresis device-
FIG. 5 is a plan view schematically showing the entire configuration of the electrophoretic device according to the second embodiment of the present invention. Hereinafter, the reference numerals of the components of the columnar structure 1A are the same as those of the columnar structure 1 in FIG.
FIG. 6 is a partial perspective view schematically showing a microchannel of the electrophoresis device according to the second embodiment of the present invention. In FIG. 6, the pillar array 4 standing in the recess 5 is not shown.
[0040]
As shown in FIG. 5, the columnar structure 1A, the reservoirs 31 to 34, the channels 35 and 36, and the electrodes 37a, 37b, 38a and 38b are provided on the plastic substrate 2A. The electrophoresis device 30 is configured by bonding a plastic substrate 2A and a transparent substrate 40 together. The columnar structure 1A, the reservoirs 31 to 34 and the channels 35 and 36 are simultaneously formed integrally with the plastic substrate 2A by the same manufacturing method as the columnar structure 1 of the first embodiment.
FIG. 5 corresponds to a view in which the plastic substrate 2A is seen through the transparent substrate 40. As the transparent substrate, a sheet or film made of PMMA, PC, PET or the like having a thickness of 50 to 500 μm is used.
[0041]
The four reservoirs 31 to 34 are recesses for storing samples of DNA molecules, RNA molecules, and the like supplied from the outside, and for collecting samples separated by electrophoresis. The channels 35 and 36 are grooves having a width of, for example, 50 μm and communicating with each other at the intersection C. Channel 35 is connected to reservoirs 32 and 34, and channel 36 is connected to reservoirs 31 and 33.
[0042]
The columnar structure 1A constitutes a part of the channel 36 of the electrophoresis device 30. The columnar structure 1 </ b> A is disposed at a position about 0.1 to 0.3 mm away from the intersection C toward the reservoir 33. The length of the columnar structure 1A along the channel is set based on the migration distance that can separate DNA molecules and the like, and is, for example, in the range of 0.3 to 50 mm.
[0043]
The electrodes 37a, 37b, 38a, and 38b are formed on the plastic substrate 2A by depositing a conductive film of Au, Pt, or the like by using evaporation or sputtering. Since the plastic substrate 2A is an insulator, even if electrodes are directly formed and an electric field is applied, problems such as a voltage drop or a short circuit due to a current flowing on the surface of the plastic substrate 2A do not occur.
[0044]
The electrode 37a is arranged near the reservoir 32, and the electrode 37b is arranged near the reservoir 34. The electrode 38a is arranged near the reservoir 31 and the electrode 38b is arranged near the reservoir 33.
In FIG. 5, the electrodes 37a and 37b are respectively connected to the negative electrode and the positive electrode of the DC power supply 37c. The electrodes 38a and 38b are connected to a negative electrode and a positive electrode of the DC power supply 38c, respectively. However, as described later, when performing the electrophoresis process, the negative electrode is switched to ground, and the positive electrode is switched to ground as needed.
[0045]
After the columnar structure 1A, the reservoirs 31 to 34, the channels 35 and 36, and the electrodes 37a, 37b, 38a and 38b are provided, the plastic substrate 2A is bonded to the transparent substrate 40 by pressure bonding via silicone rubber.
[0046]
The surface 2a of the plastic substrate 2A and the head 3a of each pillar 3 are firmly joined to the transparent substrate 40. As shown in FIG. 6, the upper part of the concave portion 5 of the columnar structure 1 </ b> A is closed by a transparent substrate 40, and a tunnel-shaped microchannel 10 extending in the arrow direction is formed.
When a sample such as a DNA molecule or an RNA molecule flows through the microchannel 10, there is no fear that these leak to the outside. Similarly, there is no possibility that the sample leaks from the reservoirs 21 to 24 and the channels 25 and 26 shown in FIG.
[0047]
As another bonding method, there is a method of bonding via a transparent cyanoacrylate-based adhesive or an ultraviolet-curable adhesive.
Before bonding, four through-holes (not shown) are formed in the transparent substrate 40 so as to communicate with the reservoirs 31 to 34, respectively. The diameter of the through hole is 1 to 3 mm. Press through processing, ultrasonic processing, or the like is used to form the through holes.
[0048]
In this way, an all plastic electrophoresis device 30 that is inexpensive and can be mass-produced is completed.
Note that the transparent substrate 40 may not be made of plastic. For example, the transparent substrate 40 may be made of a transparent inorganic material such as glass or quartz and bonded to the plastic substrate 2A via an adhesive.
[0049]
Next, a procedure for separating DNA using the electrophoresis device 30 of the present embodiment will be described with reference to FIG.
After the buffer solution for analysis is injected into the electrophoresis device 30, the DNA sample stained with the fluorescent reagent is supplied to the reservoir 32. DNA samples are mixed samples having various molecular sizes. A voltage is applied using the electrode 37b as a positive electrode. At this time, the electrodes 37a, 38a, 38b are grounded. Since the DNA molecule is negatively charged, the DNA molecule moves from bottom to top on the paper surface in the channel 35.
[0050]
When the DNA sample moves to the intersection C, a voltage is applied with the electrode 38b as the positive electrode. At this time, the electrodes 37a, 37b, 38a are grounded. The DNA sample changes its direction and moves from right to left on the paper surface in the channel 36, passes through the microchannel 10, and is collected by the reservoir 33.
[0051]
The appearance of the DNA sample passing through the microchannel 10 can be observed through the transparent substrate 40 with a fluorescence microscope. The objective lens of the fluorescence microscope is set right above the microchannel 10 so that its optical axis is orthogonal to the surface of the transparent substrate 40. Although the thickness of the transparent substrate 40 is 50 to 500 μm, it is preferable to use a thin transparent substrate when the observation magnification is high because the depth of focus is short.
[0052]
Electrophoresis was performed using a DNA sample having a molecular size of 200 bp and 300 bp, with the length of the microchannel 10 set to 1 mm, the gap between the pillars set to 300 nm, and the applied voltage between the electrodes 28a and 28b set to 600V. In the observation by the fluorescence microscope, a state where the DNA molecules were moving in the microchannel 10 could be observed. In addition, separation of two types of DNA molecules was confirmed.
[0053]
In the electrophoresis device 30 of the present embodiment, the gap between the pillars standing in the microchannel 10 is 300 nm. However, the present invention is not limited to this, and is appropriately selected according to the molecular size of the DNA sample. be able to. When the molecular size is large, the gap between the pillars is widened, and when the molecular size is small, the gap between the pillars is narrowed, thereby enabling accurate separation in a short time. The gap between the pillars depends on the shape of the matrix 11.
The gap between the pillars is preferably in the range of 5 nm to 10 μm. When a columnar structure is used for an electrophoresis device for separating a biological sample, the sizes of DNA, cells, and proteins are substantially in this range, so that any biological sample can be separated.
[0054]
The arrangement pitch of the pillar array 4 does not need to be constant. The arrangement pitch may be increased in the upstream portion of the microchannel 10, and may be decreased in the downstream portion. Further, the arrangement pitch may be changed continuously. For a DNA sample having a wide range of molecular sizes, clogging of large molecular size DNA can be prevented, and small molecular size DNA can be accurately separated. The arrangement pitch of the pillar array 4 also depends on the shape of the matrix 11.
[0055]
Further, the shape of the pillar 3 is a straight cylinder, but may be formed so that the diameter of the pillar changes in the height direction, or the shape of the pillar may be partially bent. A portion having a large gap between pillars has an effect of preventing clogging of DNA having a large molecular size, and a portion having a small gap between pillars can accurately separate DNA having a small molecular size.
Since the pillars 3 are made of plastic and have elasticity, they are not damaged by the releasing operation in the final step of the injection molding.
[0056]
The columnar structure of the present invention can be applied not only to an electrophoretic device but also to various filters such as a fine particle filter.
[0057]
【The invention's effect】
As described above, according to the present invention, an inexpensive columnar structure and an electrophoretic device can be provided by using plastic.
[Brief description of the drawings]
FIG. 1 is a partial perspective view schematically showing a structure of a columnar structure according to a first embodiment of the present invention.
FIG. 2 is a partial cross-sectional view showing a manufacturing process of the columnar structure according to the first embodiment of the present invention.
FIG. 3 is a partial perspective view schematically showing a matrix of the columnar structure according to the first embodiment of the present invention.
FIG. 4 is a partial cross-sectional view showing a step of manufacturing a matrix of the columnar structure according to the first embodiment of the present invention.
FIG. 5 is a plan view schematically showing an entire configuration of an electrophoretic device according to a second embodiment of the present invention.
FIG. 6 is a partial perspective view schematically showing a microchannel which is a component of the electrophoresis device according to the second embodiment of the present invention.
[Explanation of symbols]
1, 1A: Columnar structure 2, 2A: Plastic substrate 3: Pillar (columnar projection)
4: pillar array 5: concave portion 10: microchannel 11: matrix (columnar structure)
20: Mold 30: Electrophoretic devices 31 to 34: Reservoir 35, 36: Channels 37a, 37b, 38a, 38b: Electrode 40: Transparent substrate

Claims (11)

A columnar structure for an electrophoretic device, wherein a plastic substrate and a number of columnar projections have an integral structure and are replicated by a molding method using a mold. The columnar structure according to claim 1,
The columnar structure for an electrophoretic device, wherein a gap between the columnar projections is in a range of 5 nm to 10 μm. The columnar structure according to claim 1 or 2,
The mold is manufactured by electroplating or electroless plating using a columnar structure formed by forming a large number of columnar projections on a silicon substrate by photolithography and thermally oxidizing the surface of the columnar projections as a matrix. A columnar structure for an electrophoretic device. The columnar structure according to claim 1 or 2,
The mold has a columnar structure formed by forming a large number of columnar protrusions on a silicon substrate by photolithography, thermally oxidizing the surface of the columnar protrusions, and forming a polycrystalline silicon film on the surface of the oxidized columnar protrusions. A columnar structure for an electrophoretic device, which is manufactured by electroplating or electroless plating as a matrix. The columnar structure according to claim 1 or 2,
The mold forms a large number of columnar projections on a silicon substrate by photolithography, thermally oxidizes the surface of the columnar projections, forms polycrystalline silicon on the surface of the oxidized columnar projections, and forms the polycrystalline silicon film. For electrophoretic devices manufactured by electroplating or electroless plating using a columnar structure formed by depositing polycrystalline silicon on an oxidized polycrystalline silicon film as a master mold by thermally oxidizing the polycrystalline silicon film. Columnar structure. The columnar structure according to claim 1 or 2,
The mold is manufactured by electroplating or electroless plating using a columnar structure formed by forming a large number of columnar projections on a silicon substrate by photolithography and forming a polycrystalline silicon film on the surface of the columnar projections as a matrix. A columnar structure for an electrophoretic device. A plurality of columnar projections are formed on a silicon substrate by photolithography, and a columnar structure formed by thermally oxidizing the surfaces of the columnar projections is used as a matrix to manufacture micro gold by electroplating or electroless plating. Type. A large number of columnar projections are formed on a silicon substrate by photolithography, the surface of the columnar projections is thermally oxidized, and a polycrystalline silicon film is formed on the surface of the oxidized columnar projections. A micro mold manufactured by plating or electroless plating. Forming a large number of columnar projections on a silicon substrate by photolithography, thermally oxidizing the surface of the columnar projections, forming polycrystalline silicon on the surface of the oxidized columnar projections, thermally oxidizing the polycrystalline silicon film, A micromold manufactured by electroplating or electroless plating using a columnar structure formed by depositing polycrystalline silicon on an oxidized polycrystalline silicon film as a matrix. A large number of columnar projections are formed on a silicon substrate by photolithography, and polycrystalline silicon is deposited on the surface of the columnar projections. And a micro mold. A microchannel comprising a columnar structure according to claim 1 and a transparent substrate joined to and joined to the tip portions of the plurality of columnar projections, and a sample is placed in the microchannel by electrophoresis. An electrophoretic device characterized by passing through and separating.

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