JP3460140B2 - Test device for analyzing liquid sample by capillary with groove - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a test device for analyzing components contained in a liquid sample, particularly an aqueous solution such as blood or urine.

[0002]

2. Description of the Related Art In a simple test device for analyzing a liquid sample by a reaction with a reagent, generally, a capillary phenomenon is used for introducing or moving the sample to a reaction site of the test device with the reagent. As this type of test tool, there are a type in which a reagent applied in a capillary tube begins to dissolve in a sample, and a type in which a sample penetrates into a reagent layer provided in the capillary tube.

As an example of the former, Japanese Patent Laid-Open No. 63-27483
No. 9 discloses a test device including a lower extension member that also serves as a handle and an upper member that forms a capillary tube with the lower extension member and a spacer and that contains a reagent. As an example of the latter, Japanese Patent Laid-Open No. 4-188065 discloses a support, a reagent layer fixed on the support, a support which is fixed so as to form a capillary chamber with the support while covering the reagent layer. An analytical tool is described which comprises a cover having an exhaust port.

[0004]

However, JP-A-63-
In the test tool described in Japanese Patent No. 274839, in which the reagent dissolves in the sample, the concentration of the reaction solution must be accurately defined. Need to dispense. Also,
The test device described in JP-A-4-188065 discloses a type in which the sample penetrates into the reagent layer, so that the reagent is placed on a paper or film separate from the capillary tube in order to maintain the volume of the reagent layer. It must be included and fixed in the capillary.

Therefore, an object of the present invention is to simply measure a fixed amount of a sample and analyze it at the same time without dispensing the sample into another container or separately preparing and fixing a reagent layer. It is to provide a test tool capable of doing the above.

[0006]

In order to achieve the object, the test device of the present invention holds a reagent at a predetermined position in a capillary tube having a test solution introducing port and an exhaust port, and supplies the test solution from the introducing port. A test tool for analyzing a specific component in a test solution with a reagent by introducing and reacting with the reagent, wherein the capillary tube moves the test solution from the test solution introduction port toward the reagent. A hydrophilic region, a second hydrophilic region having a constant area for holding a reagent, a first hydrophilic region and a second hydrophilic region are separated from each other, and the first hydrophilic region and the second hydrophilic region are passed through. A hydrophobic region which communicates with the exhaust port without being provided, and a groove which is provided at the boundary between the hydrophobic region and the second hydrophilic region and has poorer wettability than the second hydrophilic region. Is characterized by.

According to this test device, the test liquid introduced from the test liquid introducing port goes toward the reagent through the first hydrophilic region by the capillary phenomenon. Along with that, the air in the capillaries is pushed out and exits from the exhaust port. When the test solution reaches the hydrophobic region, the hydrophobic region temporarily stops the movement. Then, when an external force is applied to the test device, the test liquid jumps out on the extension of the first hydrophilic region and enters the hydrophobic region.

Most of the test liquid proceeds in the same direction and enters the second hydrophilic region. However, if the hydrophobic region and the second hydrophilic region are continuous in the same plane, the test liquid entering the second hydrophilic region tends to form a meniscus at the boundary with the hydrophobic region. When this meniscus is convex, there is no problem, but when it is concave, the test liquid flows along the tube wall and gradually flows from the exhaust port. Therefore, the test liquid cannot be quantitatively retained in the second hydrophilic region. On the other hand, in the present invention, since the groove having less wettability than the second hydrophilic region is provided at the boundary between the hydrophobic region and the second hydrophilic region, the groove is wet in two regions. The meniscus is regulated by further emphasizing the difference in sex.

On the other hand, since the area of the second hydrophilic region is constant, the amount of the test liquid retained is determined by the area and the inner diameter of the capillary tube. When passing through the hydrophobic region and moving to the second hydrophilic region, the test liquid remaining on the hydrophobic region or the part that could not be retained in the second hydrophilic region is rejected by being repelled by the hydrophobic region. It Therefore, a specific component in the test liquid can be analyzed with high accuracy by the reaction between the held fixed amount of the test liquid and the reagent.

The external force applied to the test liquid to pass through the hydrophobic region is, for example, a momentary vibration caused by shaking the test tool with an operator's hand, a centrifugal force, a suction force caused by suction from an exhaust port, an inlet port. It is the pressing force from. The exhaust port is
It is preferably a through hole provided in a direction intersecting with the capillary tube. By providing the through-hole in this way, the capillary tube can be formed into a bag-like tube in which only the test solution inlet is opened except the through-hole, and the overflow of the test solution retained in the second hydrophilic region can be prevented. . The crossing angle between the through hole and the first hydrophilic region side of the capillary is preferably an acute angle. This makes it possible to prevent the test liquid from jumping out of the through hole and contaminating the surroundings when the test liquid is moved to the second hydrophilic region by an external force.

The groove is preferably provided all around the hydrophobic region including the boundary with the second hydrophilic region. This is for the following reason. Whether a region is hydrophilic or hydrophobic is relatively determined. As a method of changing the wettability in the capillaries, there are a case where it is modified to be hydrophilic rather than the original property and a case where it is modified to be hydrophobic than the original property. In the present invention, at least two hydrophilic regions and at least one hydrophobic region must be formed in the capillaries. Therefore, the aspect of the combination is that (1) the hydrophobic region remains the original property, and the portion that becomes the hydrophilic region is modified to be more hydrophilic than the original property, (2) the hydrophobic region and The part that becomes the hydrophobic property is modified to be more hydrophobic than the original property, and the hydrophilic region is left as it was. (3) The part that becomes the hydrophobic region is modified to be more hydrophobic than the original property. , The hydrophilic region is modified to be more hydrophilic than the original property. And
The modification to be hydrophilic is made by physical means such as UV irradiation, while the modification to be hydrophobic is usually made by applying a water repellent. The groove serves to prevent the water repellent applied to the hydrophobic region from flowing toward the hydrophilic region. Therefore, by providing the groove in the entire periphery of the hydrophobic region, the boundary between the hydrophobic region and the hydrophilic region can be made clear.

When the diameter of the capillary when the groove is provided is 100 to 800 μm in the depth direction of the groove, the depth of the groove is preferably 1/10 to 1/2 of the capillary diameter.
Is. The hydrophobic region is divided into a first hydrophobic region that separates the first hydrophilic region and the second hydrophilic region, and a second hydrophobic region that sandwiches the second hydrophilic region together with the first hydrophobic region. You may have. In this case, the second hydrophobic region can be communicated with the exhaust port without passing through the first hydrophilic region and the second hydrophilic region. By doing so, the air in the capillary tube can be easily removed, and the moving speed of the test solution can be increased. It is particularly preferable to provide the exhaust port on the extension of the second hydrophobic region. You can release both ends of the capillary,
This is because it becomes easier to remove air.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a test device according to an embodiment of the present invention.
2 is a plan view and FIG. 2 is a sectional view. The test tool 21 includes a rectangular parallelepiped main body 22. The main body 22 is composed of three transparent plates, the middle plate is processed into a frame shape, and a long and narrow cavity 23 surrounded by the frame and the upper and lower plates functions as a capillary tube. The cavity 23 starts at one end of the body 22,
It is blocked on the way without reaching the other end. In this example, the starting portion becomes the introduction port 24.

The inner surface of the cavity 23 is composed of a first hydrophilic region 231, a hydrophobic region 232 and a second hydrophilic region 233 in order from the inlet 24 side. The cavity 23 is the second hydrophilic region 23.
Close at the back of 3. The cavity 23 has a rectangular hydrophobic region 2
Grooves 26 are provided in the entire periphery of 32 so as to vertically face each other. In the main body 22, the amphiphilic regions 231, 233
A through hole 25 is provided which allows the hydrophobic region 232 to communicate with the outside without passing through. This through hole 25 functions as an exhaust port. A reagent (not shown) is applied to the second hydrophilic region 233.

The manufacturing method of the test tool 21 is as follows, for example. Two rectangular plates made of polystyrene (PS) and one rectangular plate made of polyvinyl chloride (PVC) are prepared. PS and PVC are hydrophobic in nature. Ultraviolet rays from a low-pressure mercury lamp as a light source are applied to portions of the first PS plate area where the hydrophilic areas 231 and 233 are to be formed. As a result, the irradiated portion is modified to be hydrophilic. The PVC plate is processed into a frame shape and the through holes 25 are opened. A predetermined portion of the second PS plate is modified to be hydrophilic like the first PS plate. A groove 2 is formed with a knife around the portions of the first PS plate and the second PS plate where the hydrophobic regions 232 are to be formed.
Cut 6 A water repellent agent such as dimethylpolysiloxane is applied to the portion surrounded by the groove 26. Because of the groove 26, the water repellent agent does not flow into the hydrophilic region. Second hydrophilic region 23
After applying a reagent (not shown) to 3, the three plates are laminated and fixed. This is the end. Unlike conventional methods, it is not necessary to mold the reagent separately.

The procedure for analyzing a liquid sample with the test tool 21 is as follows. The amount of blood that has been collected or blood that has been subjected to blood cell separation treatment is slightly larger than the optimum amount.
Press on 4. The blood moves toward the second hydrophilic region 233 by capillarity while wetting the first hydrophilic region 231, but is blocked by the hydrophobic region 232 on the way. When the blood as collected is used as a sample, a pretreatment unit such as a blood cell separation membrane may be provided in the middle of the first hydrophilic region 231. Therefore, the end surface of the main body 22 (the right side surface in the drawing) is tapped. The blood filled in the first hydrophilic region 231 jumps out of the first hydrophilic region 231 by the external force, passes through the hydrophobic region 232, and moves to the second hydrophilic region 233. At the same time, the air in the space surrounded by the second hydrophilic region 233 is also removed from the through hole 25. Blood begins to react with the reagents. Since the hydrophobic region 232 is not wet with blood and the groove 26 is provided at the boundary between the hydrophobic region 232 and the second hydrophilic region 233, the amount of blood filled in the second hydrophilic region 233 is always constant. Is. Therefore,
Quantitative analysis can be performed with high accuracy. Moreover, since the main body 22 is transparent, it is possible to quickly analyze by optical means.

Next, the test device of the second embodiment is shown in a plan view in FIG. 4 and a sectional view in FIG. This test tool 29
(1) The through hole 25 is not provided, and (2) the cavity 27 is open on the side opposite to the inlet 278.
5 has an exhaust function in place of the through hole 25, (3)
The hydrophobic regions 272 and 274 in the cavity 27 are separated into two places so as to sandwich the second hydrophilic region 273, (4)
Therefore, the second hydrophilic region 273 and the second hydrophobic region 274 are
The structure is the same as that of the first embodiment except that the groove 262 is also provided at the boundary with the first embodiment.

When the test tool 29 is used for analysis, the air in the cavity 27 is removed from the opening 275 as the test solution progresses due to the capillary phenomenon. Hydrophobic regions 272, 27
No liquid gets wet in 4. Moreover, both hydrophobic regions 272, 2
Since the groove 276 is provided at the boundary between the second hydrophilic region 273 and the second hydrophilic region 273, the amount of blood filled in the second hydrophilic region 273 is always constant. Then, the second hydrophilic region 273
Since air is removed from the opening 275 on the extension of
The test solution progresses quickly.

[0019]

EXAMPLE A test tool 21 having the shape shown in FIGS. 1 and 2 has a cavity 23 having a width of 3 mm, a height of 500 μm, a second hydrophilic region 233 having a depth of 3 mm, and a groove 26 having a depth of 1.
A product having a thickness of 30 μm was manufactured.

Human plasma was introduced into the test device 21 as a test solution through the inlet 24, and an external force was applied to move the test solution to the second hydrophilic region 233. For comparison, as shown in FIG. 3, a test tool 21 ′ having the same shape and quality as the test tool 21 except that the groove 26 is not provided is manufactured, and the test solution is similarly moved to the second hydrophilic region 233 ′. Let At this time, the test liquid retained in the second hydrophilic regions 233, 233 ′ forms a meniscus as shown in FIG. 4 (A) at the boundary with the hydrophobic regions 232, 232 ′, or the test liquid in FIG. It was observed whether a linear interface was formed as shown in B). The number of test tools was 20 for both test tool 21 and test tool 21 '.

After a further 3 minutes, the retained test solution was taken out with a microsyringe and the amount thereof was measured to evaluate the retaining accuracy. The results of these evaluations are shown in Table 1. In Table 1, the number in column A shows the number of test tools forming a meniscus as shown in FIG. 4 (A), and the number in column B forms a linear interface as shown in FIG. 4 (B). The number of test tools is shown.

[0022]

[Table 1] (n = 20) ------------------------- Test tool A B Holding accuracy (CV%) ---------- −−−−−−−−−−−−−−−− 21 0 20 0.9 21 ′ 20 0 3.4 −−−−−−−−−−−−−−−−−−−−− ----- As seen in Table 1, according to the test device of the present example, when the test liquid is moved to the part where the reagent is held, the test liquid is quantitatively held without forming a meniscus. .

[0023]

EFFECTS OF THE INVENTION Since the present invention has the above-mentioned features, the reagent can be fixed only by applying the reagent to a predetermined position, so that the test tool can be manufactured with a small number of steps. Further, since the test liquid can be spotted and analyzed without weighing it with a measuring instrument, the test liquid can be analyzed quickly and easily.

[Brief description of drawings]

FIG. 1 is a plan view showing a test device of a first embodiment.

FIG. 2 is a cross-sectional view showing the test device of the first embodiment.

FIG. 3 is a cross-sectional view showing a test device of a comparative example.

FIG. 4A is a plan view of a capillary tube for explaining each evaluation method of an example and FIG. 4B of a comparative example.

FIG. 5 is a plan view showing a test device of a second embodiment.

FIG. 6 is a cross-sectional view showing a test device of a second embodiment.

[Explanation of symbols]

21,29 test tool 22,272 main body 23,27 cavities 24,278 inlet 25,275 exhaust port 231,271 first hydrophilic region 232, 272, 274 hydrophobic region 233, 273 second hydrophilic region 26,276 groove

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01N 33/52 G01N 31/22

Claims (5)

(57) [Claims] 1. A reagent is held at a predetermined position in a capillary having a test solution inlet and an exhaust port, and the test solution is introduced from the inlet and reacted with the reagent, whereby a specific component in the test solution is converted into a reagent. A test device for analysis, wherein the capillary comprises a first hydrophilic region for moving a test solution from a test solution inlet to a reagent, and a second hydrophilic region having a certain area for holding the reagent. An area, a hydrophobic area that separates the first hydrophilic area and the second hydrophilic area and communicates with the exhaust port without passing through the first hydrophilic area and the second hydrophilic area, and a hydrophobic area and a second area. A test device, comprising: a groove provided at a boundary between the second hydrophilic region and having a wettability lower than that of the second hydrophilic region. 2. The test device according to claim 1, wherein the groove is provided in the entire periphery of the hydrophobic region including the boundary with the second hydrophilic region. 3. The test device according to claim 1, wherein the diameter of the capillary tube is 100 to 800 μm in the depth direction of the groove, and the depth of the groove is 1/10 to 1/2 of the capillary diameter. 4. The first hydrophilic region sandwiching the second hydrophilic region together with the first hydrophobic region, wherein the hydrophobic region separates the first hydrophilic region and the second hydrophilic region from each other. The test device according to claim 1, wherein the test device is separated into a hydrophilic region and a second hydrophobic region communicating with the exhaust port without passing through the second hydrophilic region. 5. The test device of claim 4, wherein the vent is on an extension of the second hydrophobic surface.