JP3438050B2 - Direct fixation of reagent layer by ultrasonic - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry analytical tool (test paper, test paper) for measuring a specific component in a liquid usually used in clinical examination fields such as urine analysis, serum analysis, whole blood analysis and immunoassay. (Sometimes referred to as a piece), a method of immobilizing a reagent layer on a base substrate that serves as a support during the production thereof.

[0002]

2. Description of the Related Art In the field of clinical examination, analysis of various components in body fluids such as blood, urine, saliva, and cerebrospinal fluid is an index for objectively knowing the effects of diagnosis and treatment of many diseases. .

The general analysis method is that a body fluid to be a sample and various solution reagents are added to a cuvette and stirred, and the cuvette is heated to 37 ° C. for a certain period of time, and then a specific component in the sample reacts. There is used a method of measuring the substance thus produced by an absorptiometer, a fluorometer, a turbidimeter or the like. This measuring method is called wet chemistry.

On the other hand, a method in which a reagent is supplied as a dry test piece, pre-preparation of the reagent is not required at all, stirring is not required, waste liquid is not generated, and a large number of items can be measured with a small amount of sample. Is being developed. This method is used as an immediate examination method in hospital emergency laboratories, night nurses' offices, and practitioners. This method is called dry chemistry.

In this dry chemistry technique, the test piece is a reagent that reacts with various components in a sample in a porous matrix (eg, paper, cloth, non-woven cloth, mesh, membrane filter, sintered body, ceramics, etc.). It is manufactured by holding it by impregnation, coating, etc. This test piece can be cut into strips and used as it is, but when expensive reagents (eg enzymes, substrates, color formers, etc.) are used, such strips can be used for measurement. If the used area remains large, it is uneconomical, resulting in a huge cost increase.

[0006] Therefore, in consideration of the size of the luminous flux (spot diameter) in the reflectometer, the measurement accuracy, and the ease of handling in manufacturing and use, the size capable of visual color comparison is maintained. , Test piece impregnated with reagent is 4mm square ~ 10m
It is cut into an m-square or a rectangle, and this is used as a reagent layer. The cut reagent layer is fixed to a base material serving as a support or a handle with an adhesive (double-sided tape, glue, instant adhesive, etc.).

[0007]

The most commonly used method for directly fixing the reagent layer to the base material is a double-sided tape fixing method as described above.
However, a polyacrylic resin is mainly used for the adhesive of the double-sided tape, and a polymerization initiator, a monomer, and a stabilizer, a plasticizer, a wetting agent are mixed in a considerable amount, and when contacting with the reagent layer, It may react with the reagent in the reagent layer to be colored or decompose the active ingredient, and thus it is necessary to carefully select the double-sided tape for each item of the reagent.

Further, in the processing step, the adhesive of the double-sided tape adheres to the processing machine and causes troubles, or the adhesive adheres to the surface of the reagent layer to cause a portion where the reagent and the sample do not react, resulting in uneven coloring. There was a problem of becoming.

As a method for solving the problem of unevenness caused by the double-sided tape, a method of fixing with hot melt (adhesive consisting of a thermoplastic resin that softens at 80 to 150 ° C.) is used, but in order to melt the hot melt. In addition, it is necessary to raise the temperature of the entire reagent layer to 100 to 110 ° C. for several seconds, and as a result, there is a risk of denaturing the substance of the reagent layer (particularly proteins such as enzymes, antibodies and antigens). In addition, a plasticizer, a stabilizer, and the like were mixed in the hot melt as in the double-sided tape, and these components had an adverse effect on the reagent.

As a method for solving these problems, Japanese Patent Publication No.
Wrap the test piece in a fabric or web in −6551,
A method is disclosed in which both sides are heat-sealed with hot melt. The method of wrapping the reagent layer with nylon mesh and heat-sealing both sides solves the above two problems, but the nylon mesh is slightly loosened by the impact during transportation, and the reagent layer is displaced as a result of loosening, or There was a risk that it would come off. Further, this processing method has an economical drawback that it is complicated and very expensive.

Japanese Patent Publication No. 6-68488 discloses a detection composition in which a thermoplastic resin is sandwiched between a reagent layer and a support, and the laminate is cut by laser or ultrasonic waves and fixed by a melted cut surface. A method of making an article is disclosed. This technique is a method for producing a dry multi-layer analytical tool without using an adhesive. The tool produced by this technique is of a type to be used after it is further mounted on a rod or a holder serving as a handle. . In addition, since a margin is cut off with a laser or an ultrasonic wave, a useless part is generated. Also, a machine for generating a laser or an ultrasonic wave having a high output capable of cutting out a substance is required, and such a machine is usually expensive.

Further, in particular, when a glass fiber filter paper or the like chemically bound with an antibody, an antigen, avidin, biotin, etc. used for the analysis of a trace component utilizing an immunoreaction (so-called dry immunoassay) is fixed to a base material, a double-sided tape In addition to the above-mentioned problems, the use of a hot melt or hot melt has a problem that non-reacted components or substances affecting the reaction in the sample are non-specifically adsorbed on the glass fiber filter paper, resulting in a large error.

[0013]

The above-mentioned problems are caused by fixing the support and the reagent layer when the dry analytical tool is prepared according to the present invention, and either the substrate base or the reagent layer serving as the support is used. It has been found that the problem can be solved by using thermoplastic resins for both or both of them, and superposing them to generate frictional heat by applying vibration and pressure by ultrasonic waves from the outside and fixing them. Since there is no concern about the inclusion of plasticizers and the like, and heat is generated instantly to cool immediately, the reagents in the reagent layer are rarely denatured. Moreover, since the base material base which is the support and the reagent layer are directly fixed, there is no blank portion to be cut off, which is economical. Since the vibration of ultrasonic waves is directly transmitted to the reagent layer, the ultrasonic oscillator can be a relatively inexpensive type.

[0014]

[Structure] The fixing method according to the present invention can take various forms. An example is shown below with the numbers in the attached figures. (Aspect 1) A method for producing a dry analytical tool for measuring a specific component in a liquid, comprising the following steps in a method for directly fixing a reagent layer on a base substrate that serves as a support. Characterized fixing method. The reagent base layer (1) is placed on the base substrate (2) so as to be in contact therewith, frictional heat is generated by externally applying vibration and pressure by ultrasonic waves, and the base substrate (contacting with the reagent layer (1) ( A step of melting either the surface of 2) or the surface of the reagent layer (1) in contact with the base material (2). The step of soaking the melted surface material of one layer into the inside of the other side by applying pressure. The step of releasing the ultrasonic vibration and the pressure. One of the layers (1) is made of a thermoplastic resin and one of them is a non-thermoplastic porous matrix.
In other words, when the base material (2) is made of a thermoplastic resin plate and the reagent layer (1) is a non-thermoplastic porous matrix coated or impregnated with a reagent, and when the base material (2) is non-heated. There are two modes in which the plate is formed of a plastic porous matrix and the reagent layer (1) is a thermoplastic resin film coated with a reagent.

In addition, both the support and the reagent layer may be made of a thermoplastic resin. It is shown below along with the numbers in the attached figures. (Aspect 2) A method for producing a dry analytical tool for measuring a specific component in a liquid, comprising a step of directly fixing a reagent layer to a base substrate as a support, which comprises the following steps: And the manufacturing method. The reagent layer (4) is arranged on the base substrate (5) so as to be in contact with the base substrate (5), and frictional heat is generated by externally applying vibration and pressure by ultrasonic waves, and the base substrate (contacted with the reagent layer (4) ( A step of melting the surface of 5) and the surface of the reagent layer (4) in contact with the base material (5). A step of integrating one surface that is melted and the other surface that is also melted by applying pressure. Step of releasing ultrasonic vibration and pressure. Both 5) and the reagent layer (4) are made of thermoplastic resin,
There are two types of shapes of the reagent layer (4): a porous matrix in which a reagent is impregnated or applied and a thermoplastic resin film in which a reagent is applied. The part where the base material base (5) and the reagent layer (4) are integrated is shown by (6) in FIG.

The thickness of the base material, whether it is made of a thermoplastic resin or a porous matrix, is sufficient as long as it can sufficiently support the reagent layer to be fixed later.
This may be the same as a normal dry analytical tool. Usually, the thickness is 0.1 mm to 0.4 mm.

Examples of the material of the non-thermoplastic porous matrix are paper (filter paper), wood, non-woven fabric (membrane filter, uniaxially stretched porous film, biaxially stretched porous film, radiation irradiated porous film), woven fabric. Examples include cloth, knitted cloth, glass (glass fiber filter paper), ceramics (porous ceramic sheet), metal cloth, membrane filter, and three-dimensional lattice structure composed of polymer microbeads. However, it is an essential condition that it does not melt by heat.

The thermoplastic resin used in the support or the reagent layer may be a thermoplastic resin of those usually used in this type of dry analytical tool, for example, polyethylene terephthalate (referred to as PET). Examples thereof include polycarbonate, polypropylene, polyethylene, polystyrene, polycarbonate, polyvinyl acetate, polyvinyl chloride, and cellulose ester.

In order to produce the dry analytical tool according to the first aspect, a reagent which specifically reacts with the substance to be detected in the liquid and exhibits a color is impregnated into the filter paper and dried to prepare a reagent layer. , Place it on a polyethylene terephthalate plate as a support, and apply pressure while applying ultrasonic waves. The melted polyethylene terephthalate on the side of the support bites into the reagent layer and is completely fixed by the so-called "river effect".

In another dry analytical tool according to the first aspect, a reagent in which a reagent that specifically reacts with a substance to be detected in a liquid and exhibits a color is kneaded with a polymer binder is applied onto a thin polyethylene terephthalate film and dried. To form a reagent layer. The reagent layer is placed on a substrate base made of a porous matrix such as filter paper and ultrasonic waves are applied. What is melted by the applied ultrasonic waves is the surface of the reagent layer film that is in contact with the base material, and the melted polyethylene terephthalate bites into the support and is completely fixed by the so-called "tack effect". The thin polyethylene terephthalate film used as the reagent layer, which is used here, may have a thickness of 50 to 150 μm which is generally used in this industry. In this aspect, when the test piece after completion is used in the dip method and the test piece is immersed in the sample solution and taken out, the excess sample solution is absorbed by the support, and the excess sample solution does not go to the reagent layer. There are also advantages.

In the dry analytical tool according to the second aspect, a reagent which is specifically reacted with a substance to be detected in a liquid to give a color and kneaded with a polymer binder is applied on a polyethylene terephthalate film and dried to prepare the reagent. Prepare the layers and place them on a polyethylene terephthalate plate,
Apply pressure while applying ultrasonic waves. Since the melted polyethylene terephthalate from the reagent layer side and the melted polyethylene terephthalate from the base material base side are in contact with each other and integrated, both are completely fixed when the temperature drops.

The method of impregnating and applying the reagent into the porous matrix and the method of applying the reagent onto the thermoplastic resin film may be those conventionally used as a method for producing a dry analytical tool. That is, a certain amount of reagents necessary for detection is dissolved and dispersed in a solvent to impregnate a porous matrix with an impregnation device or the like, or the reagents are kneaded together with a solvent and a polymer binder and applied on a film. Apply with a machine and then dry with a dryer.

The reagent layer and the support are arranged, and the frequency is 20 kHz.
Ultrasonic vibration of z and pressure of 60-80 kg / cm ² are applied. This state is maintained for 0 commas for a few seconds, and then ultrasonic vibration is stopped. In the state of pressure only, hold for 0 comma for a few seconds and then release the pressure. After this step, the reagent layer and the support are fixed.

When ultrasonic fusion is fixed on all the surfaces of the reagent layer and the support which are in contact with each other, the reagent is slightly affected by the heat of fusion. Although it is a slight effect that does not need to be avoided, in order to avoid this, ultrasonic welding may be performed in a streak-like or dot-like manner only in the vicinity of the periphery, avoiding the central portion of the reagent layer. An example of the dot shape is shown in FIG.

[0025]

EXAMPLE An example of a method for preparing a dry analytical tool having a reagent layer fixed thereon by the method of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the examples.

As an example, a test piece for detecting occult blood in urine was prepared with the following formulation.

A first-stage impregnating solution was prepared based on the formulation shown in the table above, immersed in a porous matrix and dried, and subsequently immersed in a second-stage impregnating solution and dried to obtain a reagent layer. .
The obtained reagent layer is allowed to stand on the base material, and the frequency is 20k.
An ultrasonic vibration of Hz and a pressure of 70 kg / cm ² were applied.
This state was maintained for 0.2 seconds, then ultrasonic vibration was stopped, and the pressure was released after the pressure was kept for another 0.2 seconds. The fusion-bonding form at that time is made into a streak shape, and the fusion-bonding state is shown in FIG. 4 and FIG. After this, as shown in FIG. 6, it was cut into a predetermined size of 5 mm width to obtain a test piece.

[0028]

[Comparative Example 1] For comparison, a reagent layer having the same formulation as that of the example was adhered onto a substrate base with a double-sided tape and cut into a predetermined size to obtain a test piece. Each test piece prepared as described above was placed in a glass bottle and sealed in the presence of a desiccant.
These were stored under an environment of 50 ° C. and an accelerated test was carried out. Two types (0 mg) with different hemoglobin concentrations as samples
/ Dl and 0.2 mg / dl, each of which is 1 sample 2), using a self-prepared control urine, a reflectance meter (spectroscopic color difference meter SZ-Σ80, Nippon Denshoku Industries Co., Ltd.) The results are shown in Table 1.

From Table 1, it can be seen that the reflectance of Sample 1 is lowered. This decrease in reflectance means coloring of the test paper and indicates that the test paper has poor stability. Further, the increase in reflectance in the sample 2 means a decrease in test paper sensitivity,
This also shows that the test paper has poor stability. From the results in Table 1, it can be seen that the test piece using the fixing method by ultrasonic welding according to the present invention has significantly improved stability.

The cause of this decrease in stability is due to the influence of components such as an organic solvent and a plasticizer which destabilize the folding composition contained in the double-sided tape. Fixing by ultrasonic welding does not have these effects, and since it is fusion bonding at the streak end, there is almost no effect of heat.

[0031]

[Comparative Example 2] In order to know the extent of the influence of heat at the time of fixing, a reagent layer similar to that of the example was not fixed on the support, but was cut into strips and prepared as a test piece. This test piece was compared with the test piece relating to the present invention.
As a sample, self-prepared control urine having a hemoglobin concentration of 0.2 mg / dl was used, and measurement was performed by a dedicated reflectometer. Table 2 shows the results obtained by measuring 5 pieces each.

From Table 2, it can be seen that the test piece subjected to ultrasonic welding in a streak shape shows results comparable to the test piece having no support. That is, this indicates that the ultrasonic fusing according to the present invention has a very small influence of heat on the reagents.

[0033]

According to the method of the present invention, since no pressure sensitive adhesive or adhesive (double-sided tape, hot melt, etc.) is used, there is no chemical influence due to these, and improvement in quality in performance can be expected. Further, since no pressure sensitive adhesive is used, there is no physical obstacle due to adhesion of glue or the like, and the cost can be reduced.
Since an inexpensive type ultrasonic oscillating device is used, the facility machine can be made simple and inexpensive in terms of production facility, and the process can be simplified, so that the manufacturing cost can be reduced.

[0034]

[Table 1]

[0035]

[Table 2]

[Brief description of drawings]

FIG. 1 is a perspective view of a test piece of the present invention when fixing of a reagent layer and a support is completed. FIG. 2 is a side sectional view showing a fixed state of the test piece according to aspect 1 of the present invention. FIG. 4 is a side sectional view showing a fixed state of the test piece according to the second aspect of the invention. FIG. 4 is a view from above when fixing of the embodiment of the present invention is completed. FIG. 6 is a view from above when a fixedly fixed test piece is cut into strips according to the present invention. FIG. 7 is a view from above a test piece fused by avoiding the central portion of the reagent layer ( 1); Reagent layer according to aspect 1 (porous matrix coated or impregnated with reagent) (2); Base substrate (plate of thermoplastic resin) (3); Melted base substrate portion (4); Aspect 2 Reagent layer (thermoplastic resin film coated with reagent) (5); Base substrate Thermoplastic resin plate) (6); melted portions (4) and (5) (7); fusion-bonded portion (streak) (8); fusion-bonded portion (dots avoiding the center of the reagent layer) )

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP 62-22063 (JP, A) JP 6-300756 (JP, A) JP 62-217159 (JP, A) JP 6- 50959 (JP, A) JP 61-288155 (JP, A) JP 7-270392 (JP, A) JP 7-18261 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01N 31/22 121 G01N 21/78 G01N 33/52

Claims (12)

(57) [Claims] 1. A method for producing a dry analytical tool for measuring a specific component in a liquid, comprising a step of directly fixing a reagent layer on a base substrate as a support, which comprises the following steps. Fixing method characterized by. The reagent layer is placed in contact with the base substrate, and frictional heat is generated by externally applying vibration and pressure by ultrasonic waves, and the surface of the base substrate in contact with the reagent layer or the base substrate is in contact. A step of melting any one of the surfaces of the reagent layer. Process of applying pressure to the melted surface material of one layer into the inside of the other side Process of releasing ultrasonic vibration and pressure 2. The base material is a thermoplastic resin plate, and the reagent layer is a non-thermoplastic porous matrix coated or impregnated with a reagent. The method described. 3. A thermoplastic resin used as a base material is polyethylene terephthalate, polycarbonate,
The method according to claim 2, which is selected from polypropylene, polyethylene, polystyrene, polycarbonate, polyvinyl acetate, polyvinyl chloride, and cellulose ester. 4. A non-thermoplastic porous matrix used as a reagent layer is paper, wood, glass, ceramics, metal cloth, non-woven cloth (membrane filter, uniaxially stretched porous film, biaxially stretched porous film, The method according to claim 2 or 3, which is selected from a radiation irradiated porous film), a sintered body, and a porous ceramic sheet. 5. The base substrate is a plate formed of a non-thermoplastic porous matrix, and the reagent layer is a thermoplastic resin film coated with a reagent.
The method according to claim 1. 6. The material of the thermoplastic resin film used as the reagent layer is selected from polyethylene terephthalate, polycarbonate, polypropylene, polyethylene, polystyrene, polycarbonate, polyvinyl acetate, polyvinyl chloride and cellulose ester. The method according to item 5. 7. A non-thermoplastic porous matrix used as a base material is paper, wood, glass, ceramics, metal cloth, non-woven cloth (membrane filter, uniaxially stretched porous film, biaxially stretched porous film). , A radiation-irradiated porous film), a sintered body, or a porous ceramic sheet. 8. A method for producing a dry analytical tool for measuring a specific component in a liquid, comprising the following steps in a method of directly fixing a reagent layer to a base material serving as a support. Characterized fixing method. The reagent layer is placed in contact with the base material, and frictional heat is generated by externally applying vibration and pressure by ultrasonic waves, and the surface of the base material in contact with the reagent layer and the base material are in contact with each other. The process of melting the surface of the existing reagent layer. Process of integrating one surface that is melting and the other surface that is also melting by applying pressure. Step of releasing ultrasonic vibration and pressure. 9. The material of the reagent layer is a porous matrix made of a thermoplastic resin coated or impregnated with a reagent, and the base material is a plate made of a thermoplastic resin.
The method according to claim 8. 10. The method according to claim 8, wherein the material of the reagent layer is a thermoplastic resin film coated with a reagent, and the base substrate is a thermoplastic resin plate. 11. The method according to claim 9 or 10, wherein the thermoplastic resin is selected from polyethylene terephthalate, polycarbonate, polypropylene, polyethylene, polystyrene, polycarbonate, polyvinyl acetate, polyvinyl chloride and cellulose ester. . 12. The fusion-bonding form of the reagent layer and the support is characterized in that dot-like fusion is performed at several points, not on the entire fusion-bonding side surface of the reagent layer. The method according to any one of claims 1 to 11.