JPH0762685B2 - Ink composition for protein detection and inspection body - Google Patents

Description

Detailed Description of the Invention

[Industrial applications]

The present invention relates to an ink composition suitable for forming a test body for detecting urinary white matter in a solution, particularly body fluid such as urine, blood, and lymph, and a test body formed using the same.

[Prior art]

Knowing the amount of protein in body fluids such as urine, blood or lymph quickly and easily plays a major role in early detection, diagnosis and treatment of renal diseases. Conventionally, to detect proteins in body fluids, especially urine,
A water-absorbent carrier is dipped in a solution containing an indicator showing a protein error and a buffer, and then the carrier is dried and then stuck on a support to produce a test body, and the test body detects the protein. Was there. This test body has the advantage that it can be operated easily and the judgment can be made in a short time, but this test body has a problem that the manufacturing process is complicated and therefore it is not suitable for mass production. Therefore, a test piece for protein detection that can simplify the manufacturing process has been proposed, and in JP-B-44-23756, a reagent mixture consisting of an indicator showing a protein error, a pH buffer and polyvinyl alcohol is provided on a support. A urine test paper cup having a detection pattern formed by coating is disclosed. See you again
57-79767 discloses an indicator, a buffer, which indicates a protein error,
A test piece for protein detection has been proposed in which a reagent composition comprising a binder and a water-absorbing powder is pattern-printed on a support.

[Problems to be Solved by the Invention]

However, in these test pieces, when the test piece is immersed in the test liquid, a part of the reagent composition on the test piece is dispersed in the sample, the form of the test reagent part changes, and the test reagent part and There is a drawback that it affects coloration in the test reagent section adjacent to the test reagent section and gives an erroneous determination result in an extreme case. The present inventors have conducted research to solve the above-mentioned problems, and as a result, by adding a specific morphological retention agent to the reagent composition for protein detection, the reagent composition when the test body is immersed in the sample It has been found that it is possible to prevent the morphological change of the test reagent part due to the absorption of the sample by the object. It is an object of the present invention to provide an ink composition for protein detection having excellent sensitivity, and a test sample for protein detection which is easy to handle and has a simple manufacturing process formed using the same. Furthermore, the present invention provides an ink composition for protein detection, which does not change the shape of the test reagent part when the test body is immersed in a specimen, and has a uniform and vivid color, and a test body formed using the same. The purpose is to do.

[Means for solving problems]

The ink composition for protein detection according to the present invention comprises a reagent composition comprising an indicator showing a protein error, a pH buffering agent, a protein-adsorbing ion exchanger, a shape-retaining agent, a binder, and a water-absorbing powder in a solvent. It is dissolved or dispersed. Further, the protein detection test body according to the present invention has a protein detection region obtained by coating the above-mentioned protein detection ink composition on a support. A water-swellable resin having a carboxyl group as a functional group is used as the shape-retaining agent. The detection of proteins in the test solution is performed by detecting the protein error in the pH of the acid side (for example, tetrabromo blue) when the protein in the test solution comes into contact with the indicator, which forms a complex with the protein. Then, the acidic color, yellow, is changed to the basic color, blue, and the degree of this color change corresponds to the amount of protein present in the sample liquid. Therefore, this principle is used. Below, each component which comprises the ink composition for protein detection which concerns on this invention is demonstrated in detail. B) Indicator showing protein error This indicator is an indicator that behaves according to the above-mentioned principle. Specifically, tetrabromophenol blue, tetrabromothymol blue, tetrabromophenolphthalein ethyl ester, tetrabromobenzara Phosphorus, bromothymol blue, etc. can be used. Of these, tetrabromophenol blue is preferable because of its excellent sensitivity. B) pH buffering agent The pH buffering agent is used to keep the pH value close to the pH at which the above-mentioned indicator indicating the protein error causes color change. Any pH buffer may be used as long as it can give a predetermined pH value (for example, pH 3 to 4) to the reagent composition. Specifically, a combination of citric acid and sodium citrate is preferably used. To be However, an excessive amount of this pH buffer or indicator on the acidic side may interfere with the color reaction that indicates a protein error.Therefore, keep the amount of the pH buffer or indicator on the acidic side to a minimum. Should be. When tetrabromophenol blue is used as the indicator, it is preferably present in an amount of 0.02 to 0.1% by weight based on the solid content of the ink composition. The c) a protein adsorbing ion exchanger ion exchanger, strongly acidic cation exchanger (functional group -SO ₃ M), weakly acidic cation exchanger (-COOM), strongly basic ion exchanger (- ^{N + R, X -, -N} + (CH 3) 2 (CH 2 CH 3 O
H)), weakly basic anion exchanger (-N (R) ₂ , -NH
(R), —NH _2, etc.) are used. Among these, a weakly acidic cation exchanger having a -COOM group (M is H or Na) as a functional group is particularly preferable, and when this ion exchanger is used, sensitivity and The color density is improved. As the matrix of the above ion exchanger, styrene-based or acryl-based synthetic resin, cellulose, silica or the like is used. However, in this case, since the reagent reaction layer immersed in the analyte liquid contains this ion exchanger, it is preferable that it is hydrophilic and excellent in water retention. From this point, the degree of cross-linking (Crosslinkag
Those with a small e) (DVB content 8% or less) are preferable. In particular, cellulose-based ones are preferable because they have the highest water retention. In addition, this cellulose matrix is fibrous
And microgranular, etc., but when the microgranular one is used as a matrix, the most excellent results are obtained in terms of sensitivity and color density. It is considered that this fine granular material has the highest protein adsorption capacity. The ion exchanger preferably has an ion exchange capacity of 0.1 to 5 meq / g (dry resin). Further, this ion exchanger changes depending on the ion exchange capacity, but when a carboxymethyl cellulose exchanger (preferably fine granules) having an ion exchange capacity of 1.0 meq / g is used, it is based on the solid content of the ink composition. It is preferably present in an amount of 5 to 30% by weight. By adding an ion exchanger into the reagent composition,
5-10 mg / dl in urine when urine is used as the test fluid
It becomes possible to detect the protein of. D) Shape-retaining agent As the shape-retaining agent, a water-swelling resin having a carboxyl group as a functional group is used, which does not impair the hydrophilicity of the printed test reagent portion and is insoluble in water. Is mentioned. Specifically, there are carboxymethyl cellulose calcium salt, carboxymethyl cellulose sodium salt and the like which are known as disintegrants for pharmaceuticals. These reagents need not have a particular ion exchange capacity. The shape-retaining agent is preferably present in an amount of 1 to 20% by weight based on the solid content of the ink composition, and particularly when a carboxymethyl cellulose salt is used, the amount of the form-maintaining agent is about 2 to 10% by weight based on the solid content of the ink composition. It is desirable to add. E) Binders Binders are required to have no effect on the components in the analyte liquid, pH, etc., and reagents, especially indicators, and do not interfere with the color reaction of indicators. . Binders confirmed to meet such requirements include (I) polyester resin, alkyd resin, polyurethane resin, polystyrene resin, acrylic resin, vinyl chloride resin, vinyl chloride copolymer resin, polyvinyl butyral resin, polyvinyl Synthetic resins such as alcohol resins and maleic anhydride copolymer resins, (II) cellulose derivatives such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose and carboxymethyl cellulose, and (III) starch, polysaccharides, gelatin, casein,
Natural polymers such as sodium alginate are used. Of these binders, maleic anhydride copolymer resins such as methyl vinyl ether / maleic anhydride copolymer, isobutylene / maleic anhydride copolymer, styrene / maleic anhydride copolymer are reacted with alcohol. Preferred are esterified products. This binder is 0.5 to 10 relative to the solid content of the ink composition.
It is preferably present in an amount of% by weight. F) Water-absorbing powder The water-absorbing powder has the function of promoting contact between the test liquid and the pH indicator and promoting the color reaction of the indicator when incorporated into the reagent composition. Such a water-absorbent powder, when contacted with water,
Those showing extreme acidity or alkalinity are not preferable, and those having high whiteness are preferable. In particular,
Kaolin, synthetic silica, glass, cellulose block,
Microcrystalline cellulose, ion exchange cellulose, ion exchange resins, calcium carbonate, magnesium carbonate, aluminum silicate and the like can be used. The water absorbing powder is preferably present in an amount of 30 to 60% by weight based on the solid content of the ink composition. G) Solvent The solvent is preferably one that can dissolve or disperse the above reagents, particularly the binder, uniformly and stably. As a solvent satisfying this condition, a non-aqueous solvent such as an aromatic hydrocarbon, an aliphatic hydrocarbon, an ester or an alcohol, water or a mixture thereof is used. However, it is preferable to use a non-aqueous solvent in that the drying step after coating the protein detecting ink composition on the support is carried out at a low temperature in a short time. When a non-aqueous solvent is used, there is also an effect that deterioration and deterioration of the reagent composition due to residual water can be prevented. H) Other components Depending on the case, in addition to the above components, a small amount of wetting agent such as nonionic surfactant, anionic surfactant, cationic surfactant, zwitterionic surfactant, polyethylene glycols, etc. It can also be incorporated into the pH measuring reagent composition. This wetting agent helps disperse each reagent, promotes formation of a uniform reagent layer, and improves water wettability. The wetting agent is 0.2 to 1 relative to the solid content of the reagent composition.
It is preferably present in an amount of 0% by weight. Further, in order to make the color tone of the indicator easier to see, a background dye such as oil yellow may be added. To prepare an ink composition for protein detection comprising the above components, first, a buffer, an ion exchanger, a morphological retainer,
And, the water-absorbing powder is crushed into particles of 50 μm or less. Then, the obtained powder is added to a liquid in which a binder and an indicator are previously dissolved or dispersed in a solvent, and a high speed stirrer, a sand mill,
It may be dispersed and kneaded with a ball mill, homogenizer, three rolls, ultrasonic disperser, or the like. The protein detecting ink composition as described above is applied on a support to form a protein detecting region, and the test body according to the present invention is obtained. As a coating technique, a printing method, a coating method (for example, roll coating, spray coating, dip coating, solid coating) or the like can be used. In the present invention, since it is preferable that the coating amount of the ink composition is relatively large and the coating amount is constant, the ink composition is applied onto the support by a silk screen printing method, an intaglio printing method, a gravure printing method or the like. It is preferable to provide. The coating amount varies depending on the type of ink composition, but is generally preferably ² to 150 g / m ² (when dried). The support is preferably one that does not react with the reagent composition and does not hinder the coloration of the reagent. Specifically, for example, paper, synthetic paper, non-woven fabric or synthetic resin film or paper and synthetic resin film And the like are used. The test object according to the present invention in which the protein test region is provided on such a support has a stick shape, a roll shape, or the like. It may be formed in a tape shape or the like. Alternatively, according to the present invention, the support itself is formed in a form capable of collecting a test liquid, for example, a cup shape, a test tube shape, a dish shape, a tray shape, and a dropper shape, and a protein test area is provided on the support body. It may be an inspection body.

【Example】

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. Example 1 A protein detection ink composition having the following composition was finely dispersed with a homomixer, and then a thickness of 300
It was printed on a μ white polystyrene sheet so as to form a square of 5 mm on a side. The screen plate used was 80 mesh, and the total thickness of the resist and screen mesh was 190μ. Ink composition for protein detection Tetrabromophenol blue 0.40 parts by weight Citric acid 25.7 parts by weight Sodium citrate 11.0 parts by weight Sorbitan monolaurate (manufactured by Kao Soap; trade name Span
20) 4.0 parts by weight Carboxymethyl cellulose sodium salt (Whatman; CM-32) 50.0 parts by weight Carboxymethyl cellulose calcium salt (manufactured by Daicel Chemical) 10.0 parts by weight Methyl vinyl ether / maleic anhydride copolymer (GA
F company; Gantrez AN-169) aluminum alcohol ester compound 4.97 parts by weight Cellulose fine powder (Asahi Kasei; trade name Avicel SF) 108
Parts by weight n-amyl alcohol 28.1 parts by weight butyl cellosolve 107.7 parts by weight butyl cellosolve acetate 50.2 parts by weight The obtained printed material was dried at 60 ° C. for 30 minutes and then cut into sticks to obtain a protein detection test body. Bovine serum albumin 20 mg / dl, 30 mg / d in normal urine and normal urine
l, 100mg / dl, 300mg / dl, and 1000mg / dl were used as a sample, and the stick was taken out immediately after immersion and left for 1 minute to observe the form and color tone of the test reagent part. did. The morphology of the test reagent part was almost completely swelling due to the absorption of the specimen, but was almost completely the same as that before immersion in the specimen. The coloration of the test reagent portion was uniform and clear, and it was possible to discriminate each concentration within the above concentration range. Comparative Example 1 A protein detecting test sample was obtained in the same manner as in Example 1 except that the protein detecting ink composition having the following composition was used. Ink composition for protein detection Tetrabromophenol blue 0.40 parts by weight Citric acid 25.7 parts by weight Sodium citrate 11.0 parts by weight Sorbitan monolaurate (manufactured by Kao Soap; trade name Span
20) 4.0 parts by weight Sodium carboxymethyl cellulose salt (Whatman; CM-32) 50.0 parts by weight Methyl vinyl ether / maleic anhydride copolymer (GA
F company; GANTREZ AN-169) amyl alcohol ester compound 4.97 parts by weight Cellulose fine powder (Asahi Kasei; trade name Avicel SF) 108
Parts by weight, n-amyl alcohol 28.1 parts by weight butyl cellosolve 107.7 parts by weight butyl cellosolve acetate 50.2 parts by weight Bovine serum albumin 20 mg / dl, 30 mg / d in normal urine and normal urine
l, 100mg / dl, 300mg / dl, and 1000mg / dl were used as a sample, and the stick was taken out immediately after immersion and left for 1 minute to observe the form and color tone of the test reagent part. did. The test reagent part swells remarkably with absorption of the sample, and a part of the test reagent part is dispersed in the sample to become a fluid composition, which is outside the range where the test reagent part was printed before being immersed in the sample. Spilled into. The coloration of the test reagent portion was nonuniform and unclear, and it was difficult to distinguish each concentration within the above concentration range.

【The invention's effect】

In the present invention, the protein detection ink composition is coated on a support by adding a morphological retainer made of a water-swelling resin having a carboxyl group as a functional group to the protein detection ink composition. By immersing the detection test body in the sample, it is possible to prevent a change in the morphology of the test reagent section caused by the absorption of the sample by the test reagent section of the test body. As is clear from the description of Examples and Comparative Examples, when the morphological agent is not added, at least a part of the test reagent part is dispersed in the sample to change the form of the test reagent part, In addition, the coloration in the test reagent section adjacent to the test reagent section becomes uneven and unclear,
It is difficult to determine the density, which may lead to an incorrect determination result. When the morphological retainer was added, the morphology of the test reagent portion did not change, and it was possible to distinguish each concentration. In addition, the test body for protein detection obtained by the present invention,
It has the above-mentioned characteristics and is directly coated on a support,
In particular, since the protein detection region can be formed by a printing method, it is advantageous for mass production and the manufacturing process can be simplified.

Claims (2)

[Claims] 1. A reagent comprising an indicator showing a protein error, a pH buffer, a protein-adsorptive ion exchanger, a water-swelling resin having a carboxyl group as a functional group, a shape-retaining agent, a binder, and a water-absorbing powder. An ink composition for protein detection, characterized in that the composition is dissolved or dispersed in a solvent. 2. A reagent comprising an indicator showing a protein error, a pH buffer, a protein-adsorptive ion exchanger, a morphological retention agent which is a water-swelling resin having a carboxyl group as a functional group, a binder, and a water-absorbing powder. An inspection body for protein detection, comprising a protein detection region formed by coating a support with an ink composition for protein detection, which is obtained by dissolving or dispersing the composition in a solvent.