A test reagent with improved specificity by suppressing false negatives

Abstract

To provide a specimen extraction liquid that contains a component capable of suppressing false negative reactions which, when detecting, with an inspection reagent that utilizes antigen antibody reaction or mutual reaction of substances having mutual action, antigens such as viruses, bacteria, proteins to be detected, etc., from specimens derived from body fluids such as nasal muddy specimens, nasal suction specimens, nasal cleaning specimens, nasal chinose specimens, studyngeal specimens, saliva specimens, excrement specimens, serum specimens and urine specimens, could not fully be suppressed by conventional methods, and a specimen extraction method and an inspection reagent using said specimen extraction liquid and method.SOLUTION: A water-soluble chemical compound having, in a structure, a phenyl group or a benzyl group or a tolyl group or a xylyl group, to which at least a carboxyl group or a functional group including its methylated or ethylated atom group or a hydroxyl group is bound, is included in the specimen extraction liquid of an inspection reagent having the specimen extraction liquid in a structure or a member, etc., that comes into contact with a specimen in a process preceding the detection reaction of the object to be detected or a simultaneous process as the detection reaction.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a technique for strongly suppressing false negative reactions that could not be completely suppressed by conventional methods. This is achieved by using a compound with a specific chemical structure in a sample extract, members that come into contact with the sample in steps before the detection reaction or simultaneously with the detection reaction, etc., when detecting a substance to be detected, such as a virus, bacterium, or protein to be detected, from a sample derived from a body fluid such as a nasal swab sample, nasal aspirate sample, nasal wash sample, nasal mucus sample, throat swab sample, saliva sample, fecal sample, serum sample, plasma sample, urine sample, etc., using a detection reagent that utilizes an antigen-antibody reaction or a binding reaction between substances having an interaction.

Background Art

[0002] In recent years, various test reagents and kits for detecting the presence or absence of pathogen infections such as viruses and bacteria, the presence or absence of pregnancy, etc., using an antigen-antibody reaction or a binding reaction between substances having an interaction have been continuously developed. All test reagents include a pretreatment step for creating conditions suitable for the detection reaction after collecting a sample from a patient, and this step is important for obtaining accurate results. In particular, many simple test reagents are characterized by not requiring special equipment, being easy to operate, and being inexpensive, and are widely used not only in large hospitals and medical testing centers but also in general hospitals and clinics, and are often used by users other than inspection experts. Therefore, it is very important that the test accuracy of the reagent is high. Examples of simple test reagents currently on the market include simple test reagents for detecting pathogen infections and simple test reagents for pregnancy diagnosis. These test reagents are often carried out at the medical institutions where patients first visit, and the presence or absence of infection or pregnancy can be determined on the spot for the samples collected from patients, and treatment measures, etc., can be taken at an early stage. Therefore, the importance of simple test reagents in medicine is increasing more and more. With the increasing use of simple test reagents, users are demanding higher reproducibility of test results and test accuracy as the performance of the reagents.

[0003] Currently, as a typical reagent for simple inspection methods, immunoassay methods that utilize antigen-antibody reactions, particularly immunochromatography, are generally known. In the immunochromatography method, a complex of a capture body (capturing substance) that specifically binds to the substance to be detected and a labeled body that specifically binds to the substance to be detected is formed on a membrane, and the label is detected / quantified to detect (measure or quantify) the substance to be detected. The immunochromatography method is widely used for detecting a wide variety of substances to be detected because the measuring device is simple and it is also excellent in terms of cost.

[0004] In one form of the immunochromatography method, a detection device is provided with a detection unit in which an antibody that specifically binds to the substance to be detected is immobilized as a capturing substance on a membrane strip such as nitrocellulose, and a labeled body unit containing a labeled body that specifically binds to the substance to be detected. A sample solution containing the substance to be detected is dropped onto the device, and while forming a complex of the substance to be detected-labeled body, it is developed and the complex is captured by the detection unit to detect or quantify the label.

[0005] In recent years, regarding clinical diagnostic agents including the immunochromatography method, it has been desired from the clinical field that the diagnostic results be more reliable, and further improvement in the reliability of the reagents has become an issue. A highly reliable test reagent is a test reagent with high sensitivity and specificity that is less likely to cause misjudgment. In particular, regarding specificity, there has always been a technical issue of how to respond to the diversity of sample components derived from differences in the background of each patient in reagent design, and more effective elimination of non-specific reactions is an extremely important issue in simple inspection methods. In order to solve these issues, it has been reported that contacting the sample with basic amino acids such as arginine and lysine, inorganic salts, glycine ethyl ester, surfactants, animal-derived immunoglobulins, surfactants and polymers having a sulfate group, surfactants having a quaternary ammonium ion, etc. can have a certain effect on improving specificity (see Patent Documents 1, 2, 3, 4, and 5), but all of them have limited effects and non-specific reactions that cannot be suppressed still exist. Therefore, a technique that can more strongly improve specificity without reducing sensitivity is desired.

Prior Art Documents

Patent Document

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0007] When detecting a substance to be detected such as a virus, bacterium, or protein to be detected from a specimen derived from a body fluid such as a nasal swab specimen, nasal aspiration specimen, nasal wash specimen, nasal mucus specimen, pharyngeal swab specimen, saliva specimen, fecal specimen, serum specimen, plasma specimen, urine specimen, etc. using a detection reagent that utilizes an antigen-antibody reaction or a binding reaction between substances having an interaction, false positive reactions and false negative reactions that could not be completely suppressed by conventional methods still exist, which is one of the factors hindering accurate diagnosis. The present invention provides a test reagent using a specimen extraction solution or a specimen extraction method containing a component capable of suppressing false negative reactions without reducing sensitivity.

Means for Solving the Problems

[0008] When the inventors used specimens derived from body fluids such as nasal swab specimens, nasal aspiration specimens, nasal lavage specimens, nasal mucus specimens, pharyngeal swab specimens, saliva specimens, fecal specimens, serum specimens, plasma specimens, and urine specimens as test samples, they intensively explored a method for more strongly suppressing non-specific reactions that occur. As a result, they found a component that can significantly suppress non-specific reactions compared to conventional methods. Furthermore, by adding this component to a specimen extract or a member that comes into contact with the specimen in a step before the detection reaction or in a step simultaneous with the detection reaction, they found that false negative reactions detected by the conventional method can be suppressed, and thus completed the present invention.

[0009] That is, the present invention has the following configurations. [1] A test kit for detecting a substance to be detected in a specimen by utilizing an antigen-antibody reaction or a binding reaction between substances having an interaction, the test reagent including a specimen extract containing a non-specific reaction suppressing component for suppressing false negatives, which is a water-soluble compound having a phenyl group, a benzyl group, a tolyl group, or a xylyl group, further having a carboxyl group, a methoxycarbonyl group, or an ethoxycarbonyl group, and optionally further having a hydroxyl group and having a molecular weight of 6000 Da or less. [2] A test reagent for immunochromatography, which is the test reagent of [1], including a specimen extract containing a non-specific reaction suppressing component for suppressing false negatives, which is a water-soluble compound having a phenyl group, a benzyl group, a tolyl group, or a xylyl group, further having a carboxyl group, a methoxycarbonyl group, or an ethoxycarbonyl group, and optionally further having a hydroxyl group and having a molecular weight of 6000 Da or less. [3] An immunochromatography test device including a site impregnated with a specimen extract containing a non-specific reaction suppressing component for suppressing false negatives, which is a water-soluble compound having a phenyl group, a benzyl group, a tolyl group, or a xylyl group, further having a carboxyl group, a methoxycarbonyl group, or an ethoxycarbonyl group, and optionally further having a hydroxyl group and having a molecular weight of 6000 Da or less, which is the test reagent of [1] or [2]. [4] The test reagent according to any one of [1] to [3], which contains a non-specific reaction inhibitory component that suppresses false negatives when the sample extract is 0.1 to 10 (w / v)%.

[0010] [5] The test reagent according to any one of [1] to [4], wherein a water-soluble compound having a phenyl group, a benzyl group, a tolyl group or a xylyl group, further having a carboxyl group, a methoxycarbonyl group or an ethoxycarbonyl group, and optionally further having a hydroxyl group, and having a molecular weight of 6000 Da or less, is a compound represented by any one of the following general formulas (I) to (V) or tryptophan: [Chemical formula] [In general formula (I), R1 is H, OH, =O, NH2, COOH, NH-CO-CNH2-C-COOH or CH3, R2 is H, CH3, C2H5, Li, Na, K, Rb, Cs or Fr, n is 0 or 1, and m is 0, 1, 2, 3 or 4.] [Chemical formula] [In general formula (II), R2 is H, CH3, C2H5, Li, Na, K, Rb, Cs or Fr, R3 is COOH, COOLi, COONa, COOK, COORb, COOCs, COOFr, COOCH3, COOC2H5, OCOH or CH3, and R3 and COOR2 are located ortho, meta or para to the benzene ring.] [Chemical formula] [In general formula (III), R2 is H, CH3, C2H5, Li, Na, K, Rb, Cs or Fr, R4 is H or CH3, and n is 0 or 1.] [Chemical formula] [In general formula (IV), R5 is the side chain of glycine, alanine, valine, leucine, isoleucine, serine, threonine, cysteine, methionine, asparagine, glutamine, phenylalanine, tyrosine, tryptophan, glutamic acid, aspartic acid, arginine, lysine or histidine.] [Chemical formula] [In general formula (V), R2 is H, CH3, C2H5, Li, Na, K, Rb, Cs or Fr, R6 is NH or O, and n is is 0, 1, 2, 3 or 4.].

[0011] [6] A water-soluble compound having a phenyl group, benzyl group, tolyl group or xylyl group, further having a carboxyl group, methoxycarbonyl group or ethoxycarbonyl group, and optionally further having a hydroxyl group, with a molecular weight of 6000 Da or less, is selected from the group consisting of aspartame, phenylalanine, phenylalanine methyl ester, mandelic acid, 2-phenylpropionic acid, 3-phenylpropionic acid, phenylglycine, phenylglycine methyl ester, phenylglycine ethyl ester, phenyl lactic acid, phenylpyruvic acid, benzoic acid, phthalic acid, acetylsalicylic acid, hippuric acid, N-toluoyl glycine, N-carbobenzyloxy amino acid, N-phenylglycine, phenoxyacetic acid, tryptophan, and metal salts of these compounds, as well as optical isomers, geometric isomers, structural isomers, stereoisomers and positional isomers of these compounds. It is a test reagent for any one of [1] to [5]. [7] A test reagent for any one of [1] to [6], wherein the sample extract further contains an amino acid or amino acid derivative selected from the group consisting of arginine, lysine, arginine ethyl ester, arginine methyl ester, glycine ethyl ester and glycine methyl ester, and optical isomers, geometric isomers, structural isomers and stereoisomers of these compounds. [8] The test reagent according to any one of [1] to [7], wherein the specimen extract further contains a halide selected from the group consisting of lithium chloride, sodium chloride, potassium chloride, sodium bromide, potassium bromide, sodium iodide, and potassium iodide.

[0012] [9] In a method for detecting a substance to be detected selected from the group consisting of viral antigens, bacterial antigens, and protein antigens in a specimen selected from the group consisting of throat swab specimens, nasal swab specimens, nasal aspirate specimens, throat wash specimens, nasal wash specimens, nasal mucus specimens, saliva specimens, serum specimens, plasma specimens, whole blood specimens, fecal specimens, fecal suspension specimens, and urine specimens, by utilizing the reaction between substances having an antigen-antibody reaction or interaction contained in the specimen extract, the specimen is preliminarily contacted with a non-specific reaction suppressing component that is a water-soluble compound having a phenyl group, benzyl group, tolyl group, or xylyl group, further having a carboxyl group, methoxycarbonyl group, or ethoxycarbonyl group, and optionally further having a hydroxyl group, and having a molecular weight of 6000 Da or less, so as to suppress a false negative reaction and perform detection.

[10] The method according to [9], wherein the method for detecting the substance to be detected is an immunochromatographic method, the specimen is put into a specimen extract containing a non-specific reaction suppressing component that is a water-soluble compound having a phenyl group, benzyl group, tolyl group, or xylyl group, further having a carboxyl group, methoxycarbonyl group, or ethoxycarbonyl group, and optionally further having a hydroxyl group, and having a molecular weight of 6000 Da or less, and the specimen extract is added to an immunochromatographic test device.

[11] The method according to [9], wherein the method for detecting the substance to be detected is an immunochromatographic method, and the specimen is added to an immunochromatographic test device including a site impregnated with a specimen extract containing a non-specific reaction suppressing component that is a water-soluble compound having a phenyl group, benzyl group, tolyl group, or xylyl group, further having a carboxyl group, methoxycarbonyl group, or ethoxycarbonyl group, and optionally further having a hydroxyl group, and having a molecular weight of 6000 Da or less.

[12] Any of the methods of [9] to

[11] , which comprises a non-specific reaction inhibitory component that suppresses false negatives when the specimen extract is 0.1 to 10 (w / v)%.

[0013]

[13] Any of the methods of [9] to

[12] , wherein a water-soluble compound having a phenyl group, a benzyl group, a tolyl group or a xylyl group, further having a carboxyl group, a methoxycarbonyl group or an ethoxycarbonyl group, and optionally further having a hydroxyl group, and having a molecular weight of 6000 Da or less, is a compound represented by any of the following general formulas (I) to (V) or tryptophan: [Chemical formula] [In general formula (I), R1 is H, OH, =O, NH2, COOH, NH-CO-CNH2-C-COOH or CH3, R2 is H, CH3, C2H5, Li, Na, K, Rb, Cs or Fr, n is 0 or 1, and m is 0, 1, 2, 3 or 4.] [Chemical formula] [In general formula (II), R2 is H, CH3, C2H5, Li, Na, K, Rb, Cs or Fr, R3 is COOH, COOLi, COONa, COOK, COORb, COOCs, COOFr, COOCH3, COOC2H5, OCOH or CH3, and R3 and COOR2 are located ortho, meta or para to the benzene ring.] [Chemical formula] [In general formula (III), R2 is H, CH3, C2H5, Li, Na, K, Rb, Cs or Fr, R4 is H or CH3, and n is 0 or 1.] [Chemical formula] [In general formula (IV), R5 is the side chain of glycine, alanine, valine, leucine, isoleucine, serine, threonine, cysteine, methionine, asparagine, glutamine, phenylalanine, tyrosine, tryptophan, glutamic acid, aspartic acid, arginine, lysine or histidine.]

Chemical formula

[0014]

[14] A compound having a phenyl group, a benzyl group, a tolyl group or a xylyl group, further having a carboxyl group, a methoxycarbonyl group or an ethoxycarbonyl group, and optionally further having a hydroxyl group, having water solubility and a molecular weight of 6000 Da or less, is a compound selected from the group consisting of aspartame, phenylalanine, phenylalanine methyl ester, mandelic acid, 2-phenylpropionic acid, 3-phenylpropionic acid, phenylglycine, phenylglycine methyl ester, phenylglycine ethyl ester, phenyl lactic acid, phenylpyruvic acid, benzoic acid, phthalic acid, acetylsalicylic acid, hippuric acid, N-toluoyl glycine, N-carbobenzyloxy amino acid, N-phenylglycine, phenoxyacetic acid, tryptophan, and metal salts of these compounds, and optical isomers, geometric isomers, structural isomers, stereoisomers and positional isomers of these compounds, according to any one of [9] to

[13] .

[15] The method according to any one of [9] to

[14] , wherein the sample extract further contains an amino acid or an amino acid derivative selected from the group consisting of arginine, lysine, arginine ethyl ester, arginine methyl ester, glycine ethyl ester and glycine methyl ester, and optical isomers, geometric isomers, structural isomers and stereoisomers of these compounds.

[16] Any of the methods of [9] to

[15] , wherein the specimen extract further contains a halide selected from the group consisting of lithium chloride, sodium chloride, potassium chloride, sodium bromide, potassium bromide, sodium iodide, and potassium iodide.

Advantages of the Invention

[0015] According to the present invention, in a detection reagent for detecting specific viruses, bacteria, proteins, low-molecular compounds, etc. by utilizing the binding reaction between substances having an antigen-antibody reaction or interaction from specimens derived from body fluids such as nasal swab specimens, nasal aspiration specimens, nasal lavage specimens, nasal mucus specimens, pharyngeal swab specimens, saliva specimens, fecal specimens, serum specimens, plasma specimens, urine specimens, etc., false negative reactions caused by specimen contamination can be more strongly suppressed, and a test reagent with high reproducibility and high test accuracy can be provided. In addition, incorrect clinical diagnoses due to non-specific reactions can be more effectively prevented, which is beneficial to both patients and users such as doctors, medical technicians, and nurses.

Brief Description of the Drawings

[0016]

Figure 1

Embodiments for Carrying Out the Invention

[0017] Hereinafter, the present invention will be described in detail. In the present invention, when detecting a substance to be detected in a specimen using a detection reagent that utilizes the binding reaction between substances having an antigen-antibody reaction or interaction, a false negative reaction is suppressed by bringing a compound into contact with the specimen, and a decrease in signal, that is, a decrease in sensitivity, is prevented. In the present invention, the antibody includes an antigen-binding fragment of the antibody.

[0018] (Specimen) The sample to be used is not limited. For example, the sample may include throat swab fluid, nasal swab fluid, nasal aspirate, throat wash, nasal wash, nasal mucus, saliva, serum, plasma, whole blood, fecal suspension, urine, culture solution, etc. These are called throat swab samples, nasal swab samples, nasal aspirate samples, throat wash samples, nasal wash samples, nasal mucus samples, saliva samples, serum samples, plasma samples, whole blood samples, fecal samples, fecal suspension samples, urine samples, culture solution samples, etc. It can be used after dilution with a buffer solution or can be used as it is without dilution.

[0019] (Substance to be detected) The substance to be detected is not limited either and can be any substance to be detected. Specific examples include viral antigens such as influenza virus, adenovirus, RS (respiratory syncytial) virus, human metapneumovirus (hMPV), hepatitis A virus (HAV), hepatitis B virus (HBV), human immunodeficiency virus (HIV), norovirus, and coronaviruses such as SARS-CoV, MERS-CoV, and SARS-CoV2; bacterial antigens such as methicillin-resistant Staphylococcus aureus (MRSA), group A streptococcus, group B streptococcus, and Legionella bacteria; toxins produced by bacteria, etc.; mycoplasma antigens; chlamydia antigens such as Chlamydia trachomatis; antigens of protozoa; antigens of fungi; hormones such as human chorionic gonadotropin; proteins such as C-reactive protein, myoglobin, cardiac troponin, and procalcitonin; various tumor markers; antigens such as pesticides and environmental hormones. Furthermore, antibodies against the above-mentioned bacteria, viruses, etc. can be mentioned.

[0020] (Collection of sample) The method for collecting the sample is not limited either. For example, for samples derived from body fluids and excreta such as throat swab samples, nasal swab samples, nasal aspirate samples, throat wash samples, nasal mucus samples, saliva samples, serum samples, plasma samples, whole blood samples, fecal samples, fecal suspension samples, urine samples, culture solution samples, etc., there are methods of collecting using a sample collection instrument such as a cotton swab, methods of collecting using suction with a suction device, methods of collecting using a blood collection tube, etc.

[0021] (Contact between the non-specific reaction inhibitory component that suppresses false negatives and the collected specimen) In the method of the present invention, the specimen is brought into contact with a non-specific reaction inhibitory component that suppresses false negatives. Here, by bringing the specimen into contact with the non-specific reaction inhibitory component that suppresses false negatives, false negatives can be suppressed when the specimen is measured. When the specimen is brought into contact with the non-specific reaction inhibitory component that suppresses false negatives, the substance to be detected and the non-specific reaction inhibitory component that suppresses false negatives come into contact. Therefore, in the method of the present invention, it can also be said that the substance to be detected is brought into contact with the non-specific reaction inhibitory component that suppresses false negatives. In addition, bringing the specimen into contact with the non-specific reaction inhibitory component that suppresses false negatives is sometimes referred to as treating the specimen with the non-specific reaction inhibitory component that suppresses false negatives.

[0022] In addition, the specimen extract refers to a liquid that suspends the substance to be detected in the specimen to make it easier to measure. For example, it is not necessary to extract a specific substance to be detected from cells or the like by dissolution or the like, and it can simply be referred to as a specimen treatment solution, a specimen diluent, a specimen suspension, or the like.

[0023] In the present invention, it is necessary to contact the specimen with the non-specific reaction inhibitory component that suppresses false negatives in advance before subjecting them to a test. Here, "before subjecting them to a test" refers to before the substance to be detected in the specimen reacts with an antibody or antigen against it, or before the substance to be detected in the specimen reacts with a substance having an interaction. The reaction with an antibody or antigen refers to the binding with an antibody or antigen, and the reaction between the substance to be detected in the specimen and a substance having an interaction refers to the binding with a substance having an interaction.

[0024] As methods for contacting the non-specific reaction inhibitory component that suppresses false negatives of the present invention with the specimen, there are a method of putting the specimen into a solution containing the non-specific reaction inhibitory component that suppresses false negatives and mixing them to bring them into contact, and a method of including a specimen extract containing the non-specific reaction inhibitory component that suppresses false negatives in a test device used for measurement, and adding the specimen to the test device used for the test to bring the specimen into contact with the non-specific reaction inhibitory component that suppresses false negatives.

[0025] As a specific example of a method of mixing and bringing a sample into contact with a solution containing a non-specific reaction suppressing component that suppresses false negatives, a non-specific reaction suppressing component that suppresses false negatives is included in a sample extract that suspends and disperses the collected sample, and when the sample is added to and mixed with the sample extract, the sample is brought into contact with the non-specific reaction suppressing component that suppresses false negatives. For example, when using a sample extract containing a non-specific reaction suppressing component that suppresses false negatives, if the sample is nasal discharge, a cotton swab is used to collect the nasal discharge, and the cotton swab dipped in the collected sample is placed in the sample extract to suspend and disperse the sample for extraction, whereby the sample can be brought into contact with the non-specific reaction suppressing component that suppresses false negatives.

[0026] As a specific example of a method of including a sample extract containing a non-specific reaction suppressing component that suppresses false negatives in an inspection device used for measurement and bringing the sample into contact with the non-specific reaction suppressing component that suppresses false negatives by adding the sample to the inspection device, a sample extract containing a non-specific reaction suppressing component that suppresses false negatives is impregnated, coated, etc. into a fibrous or porous substrate such as a pad or a filter made of non-woven fabric, fabric, sponge, etc. that the inspection device has, and when the collected sample is added to the inspection device, the sample is brought into contact with the non-specific reaction suppressing component that suppresses false negatives included in the fibrous or porous substrate. As such an inspection device, a device for an immunochromatographic method described later can be mentioned.

[0027] The material of the porous substrate of the test device is not limited in any way, and examples include pulp, cotton, wool, polyester, polypropylene, nylon, acrylic glass fiber, nitrocellulose, and the like. When a specimen extract containing a non-specific reaction suppressing component that suppresses false negatives is included in the test device used for measurement, and the specimen is added to the test device to bring the specimen into contact with the non-specific reaction suppressing component that suppresses false negatives, for example, the specimen extract containing the non-specific reaction suppressing component that suppresses false negatives is impregnated into the porous substrate and dried, and the specimen may be brought into contact with the porous substrate in a step before or simultaneously with the step in which a reaction for detecting the substance to be detected occurs on the test device. For example, when a specimen is added to the test device, the specimen spreads on the test device and reaches the site where the reaction on the device occurs, and a reaction such as an antibody-antigen reaction occurs. By providing a porous substrate containing a specimen extract containing a non-specific reaction suppressing component that suppresses false negatives at a site before the site where the reaction occurs on the test device, the specimen comes into contact with the non-specific reaction suppressing component that suppresses false negatives before the reaction. For example, a filter may be used as the porous substrate, and a filter containing a specimen extract containing a non-specific reaction suppressing component that suppresses false negatives may be provided at the site where the specimen is added. In this case, when nasal discharge is used as the specimen, a cotton swab is used to collect the nasal discharge, and the cotton swab immersed in the collected specimen is placed in a specimen extract having an arbitrary composition that does not contain a non-specific reaction suppressing component that suppresses false negatives to disperse and dissolve the specimen. Then, the above-described specimen extract is impregnated into a filter containing a non-specific reaction suppressing component that suppresses false negatives, which is a component of the test device, so that the specimen can be brought into contact with the non-specific reaction suppressing component that suppresses false negatives.

[0028] (Non-specific reaction suppressing component for suppressing false negatives and concentration) The non-specific reaction inhibitory component for suppressing false negatives of the present invention refers to a water-soluble compound having a phenyl group, a benzyl group, a tolyl group or a xylyl group, further having a carboxyl group, a methoxycarbonyl group or an ethoxycarbonyl group, and optionally further having a hydroxyl group, with a molecular weight of 6000 Da or less. Also included are optical isomers, geometric isomers, structural isomers, stereoisomers and positional isomers, including metal salts of these compounds.

[0029] These compounds are compounds represented by any of the following general formulas (I) to (V) or tryptophan.

[0030] [Chemical formula] [In general formula (I), R1 is H, OH, =O, NH2, COOH, NH-CO-CNH2-C-COOH or CH3, R2 is H, CH3, C2H5, Li, Na, K, Rb, Cs or Fr, n is 0 or 1, and m is 0, 1, 2, 3 or 4.]

[0031] [Chemical formula] [In general formula (II), R2 is H, CH3, C2H5, Li, Na, K, Rb, Cs or Fr, R3 is COOH, COOLi, COONa, COOK, COORb, COOCs, COOFr, COOCH3, COOC2H5, OCOH or CH3, and R3 and COOR2 are located ortho, meta or para on the benzene ring.] [Chemical formula] [In general formula (III), R2 is H, CH3, C2H5, Li, Na, K, Rb, Cs or Fr, R4 is H or CH3, and n is 0 or 1.]

[0032] [Chemical formula] [In general formula (IV), R5 is the side chain of glycine, alanine, valine, leucine, isoleucine, serine, threonine, cysteine, methionine, asparagine, glutamine, phenylalanine, tyrosine, tryptophan, glutamic acid, aspartic acid, arginine, lysine or histidine.]

[0033] [Chemical formula] [In general formula (V), R2 is H, CH3, C2H5, Li, Na, K, Rb, Cs or Fr, R6 is NH or O, and n is is 0, 1, 2, 3 or 4.]

[0034] Although not limited, for example, compounds selected from the group consisting of aspartame, phenylalanine, phenylalanine methyl ester (including hydrochloride), mandelic acid, 2-phenylpropionic acid, 3-phenylpropionic acid, phenylglycine, phenylglycine methyl ester, phenylglycine ethyl ester, phenyl lactic acid, phenylpyruvic acid, benzoic acid, phthalic acid, acetylsalicylic acid, hippuric acid, N-toluoyl glycine, N-carbobenzyloxy amino acid, N-phenylglycine, phenoxyacetic acid, tryptophan, and their metal salts, including optical isomers, geometric isomers, structural isomers, stereoisomers and positional isomers, are included. In the present invention, when referring to aspartame, phenylalanine, phenylalanine methyl ester (including hydrochloride), mandelic acid, 2-phenylpropionic acid, 3-phenylpropionic acid, phenylglycine, phenylglycine methyl ester, phenylglycine ethyl ester, phenyl lactic acid, phenylpyruvic acid, benzoic acid, phthalic acid, acetylsalicylic acid, hippuric acid, N-toluoyl glycine, N-carbobenzyloxy amino acid, N-phenylglycine, phenoxyacetic acid, tryptophan, their metal salts are included, and further optical isomers, geometric isomers, structural isomers, stereoisomers and positional isomers are also included. Examples of the metal salts include Li salts, Na salts, K salts, Rb salts, Cs salts, Fr salts, etc.]

[0035] Examples of the compound represented by the general formula (I) include aspartame, phenylalanine, phenylalanine methyl ester, mandelic acid, 2-phenylpropionic acid, 3-phenylpropionic acid, phenylglycine, phenylglycine methyl ester, phenylglycine ethyl ester, phenyllactic acid, phenylpyruvic acid, and benzoic acid. Examples of the compound represented by the general formula (II) include phthalic acid and acetylsalicylic acid. Examples of the compound represented by the general formula (III) include hippuric acid and N-toluoyl glycine. Examples of the compound represented by the general formula (IV) include N-carbobenzyloxy amino acid. Examples of the compound represented by the general formula (V) include N-phenylglycine and phenoxyacetic acid.

[0036] These non-specific reaction inhibitory components for suppressing false negatives are contained in members such as filtration filters that come into contact with the specimen in a step before the specimen extraction solution or the detection reaction. The concentration is preferably 0.001 (w / v)% or more, more preferably 0.1 (w / v)% or more, and most preferably 1 (w / v)% or more. Also, a plurality of these non-specific reaction inhibitory components can be used simultaneously, and in that case, the concentration is also preferably 0.001 (w / v)% or more, more preferably 0.1 (w / v)% or more, and most preferably 1 (w / v)% or more. There is no need to define an upper limit for the concentration, but for example, it is 10 (w / v)% or less, or 5 (w / v)% or less. In addition, when including a specimen extraction solution containing a non-specific reaction inhibitory component for suppressing false negatives in a porous substrate such as a filtration filter, the non-specific reaction inhibitory component having the above-mentioned concentration may be included in the porous substrate.

[0037] (Other components other than the non-specific reaction inhibitory component for suppressing false negatives) In the solution to be incorporated into members such as a porous substrate that comes into contact with the specimen in the specimen extraction solution or in a process prior to the detection reaction in the present invention, in addition to the non-specific reaction suppression component that suppresses false negatives, known substances that can reduce non-specific reactions, surfactants, pH buffering components, various proteins, salts, and saccharides may be included. For example, as components that can reduce non-specific reactions, arginine, arginine ethyl ester, arginine methyl ester, glycine ethyl ester, glycine methyl ester, lysine, and various isomers of the above-mentioned compounds can be mentioned. Examples of surfactants include nonionic surfactants such as polyethylene glycol mono-p-isooctylphenyl ether and polyoxyethylene sorbitan monolaurate, zwitterionic surfactants such as CHAPS and laurylamidobetaine, anionic surfactants such as sodium dodecyl sulfate, and cationic surfactants such as dodecyltrimethylammonium chloride. The concentration of the surfactant in the specimen extraction solution is preferably 0.5 to 5 (w / v)%, more preferably 1 to 3 (w / v)%, and even more preferably 1.5 to 2.5 (w / v)%.

[0038] Examples of buffering components include phosphate buffer, Tris buffer, and Good buffer. Examples of protein components include BSA (bovine serum albumin), casein, gelatin, IgG, etc. Examples of salts include halides such as lithium chloride, sodium chloride, potassium chloride, sodium bromide, potassium bromide, sodium iodide, and potassium iodide.

[0039] (Detection method) In the method of the present invention, detection is performed by a method using an antigen-antibody reaction or a binding reaction between substances having an interaction. Examples of combinations of substances having an interaction include combinations of a ligand and a receptor, combinations of a receptor and a receptor, combinations of biotin and avidin or streptavidin, etc.

[0040] The detection method is not particularly limited as long as it uses substances having antigen-antibody reactions or interactions. Examples include immunochromatography, latex agglutination, immunoturbidimetry, immunocoprecipitation, chemiluminescent enzyme immunoassay (CLEIA), enzyme immunoassay (EIA), enzyme-linked immunosorbent assay (ELISA), etc. Immunochromatography is particularly preferred. Many of these are immunological techniques that utilize antigen-antibody reactions, but reactions between substances having interactions can also be used instead of antigen-antibody reactions. Among these methods, the sandwich method is preferred. In a typical sandwich method, a first substance that binds to the substance to be detected is immobilized on a specific carrier as a substance for capturing the substance to be detected, and the substance to be detected is bound to this substance. Then, a second substance that binds to the substance to be detected and is labeled is bound to the substance to be detected, forming a complex of "a first substance that binds to the substance to be detected - the substance to be detected - a second substance that binds to the substance to be detected and is labeled" (the "-" indicates binding), and the substance to be detected is measured by measuring the signal emitted from the labeled substance. The first substance that binds to the substance to be detected and the second substance that binds to the substance to be detected may be the same substance. The substances that bind to the substance to be detected may be an antigen and an antibody or an antibody and an antigen, or substances that interact with each other. As the solid phase on which the first substance that binds to the substance to be detected is immobilized, any substance such as a protein that can be immobilized by a known technique can be used. For example, a porous thin film (membrane) having capillary action, particulate matter, a test tube, a resin plate, etc., known ones can be arbitrarily selected. Also, as the substance for labeling the second substance that binds to the substance to be detected, an enzyme, a radioisotope, a fluorescent substance, a luminescent substance, colored particles, colloidal particles, etc. can be used.

[0041] Among the sandwich methods, from the viewpoints of simplicity and rapidity of clinical tests, immunochromatography, which is a lateral flow type immunoassay using a membrane, is particularly preferred.

[0042] Hereinafter, a general immunochromatography method using an antigen-antibody reaction will be described. An immunochromatography test device is shown in FIG. 1.

[0043] The top of Fig. 1 is a top view, and the bottom is a cutaway sectional view. In the inspection device, various parts are laminated on a nitrocellulose membrane (a) laminated on a plastic plate (f). In the specific example of the figure, on the plastic plate (f), there is a nitrocellulose membrane (a) on which two detection parts (c) are formed with a substance to capture a substance to be detected such as an antibody, an absorption pad part (e) formed of filter paper, a label part (b), and a sample addition part (d) formed of a glass fiber filter, which are laminated respectively.

[0044] And, as shown in the figure, one end region of the absorption pad part (e) is overlapped with one end region of the nitrocellulose membrane (a), one end region of the other end region of the nitrocellulose membrane (a) and the label part (b), and one end region of the other end region of the label part (b) and the sample addition part (d), respectively, whereby a continuous lateral flow channel is formed.

[0045] The label part (b) contains a label in which a labeling substance is chemically or physically bound to a substance to capture a substance to be detected such as an antibody. Examples of the labeling substance include gold colloid particles, platinum colloid particles, color latex particles, magnetic particles, enzymes, quantum dots, fluorescent dyes, and phosphors. The label part is composed of a porous substrate containing the above label, and the material of the substrate can be generally used glass fiber (glass fiber), non-woven fabric, etc. The porous substrate impregnated with the above label and dried is also called a stabilized dry label pad. That is, the label part is a part containing the above stabilized dry label pad containing an antibody that binds to a substance to be detected by an antigen-antibody reaction and is labeled with colored latex particles.

[0046] In addition, the detection part (c) is a part where an antibody that binds to a substance to be detected by an antigen-antibody reaction is solid-phased linearly as a capture substance.

[0047] Examples of members that come into contact with the specimen in steps before the detection reaction of the substance to be detected or in steps simultaneous with the detection reaction include the above (a), (b), and (c), etc. However, it is not limited to these as long as it is a member that comes into contact with the specimen in steps before the detection reaction of the substance to be detected or in steps simultaneous with the detection reaction. When the specimen is added to the sample addition section (c), the specimen flows from the sample addition section (c) toward the absorption pad section (e). When the flow from the sample addition section (c) to the absorption pad section (e) is expressed as a flow from upstream to downstream, the member that comes into contact with the specimen in steps before the detection reaction of the substance to be detected or in steps simultaneous with the detection reaction can be said to exist upstream of the site where the detection reaction occurs.

[0048] Next, an immunoassay method using this test device will be described. First, the specimen is suspended in a specimen extraction solution to prepare a specimen sample from which the substance to be detected has been extracted. Next, the specimen sample is dropped onto the sample addition section (c) of the test device. The specimen sample containing the substance to be detected moves horizontally on the membrane, impregnates the labeled body section (b), dissolves the labeled body, and develops. If the substance to be detected is present in the specimen sample, a complex of the substance to be detected - labeled body is formed. When this complex reaches the detection section (d), a complex of the capture antibody - substance to be detected - labeled body is formed on the line thereof. The presence or absence of the substance to be detected in the specimen can be determined by detecting the presence of the complex based on the signal emitted from the labeled substance in this complex. Other components and the like that did not participate in the reaction are absorbed by the absorption pad section (e). In the example shown in FIG. 1, there are two detection sections (d), which are for capturing two types of substances to be detected, such as influenza A virus and influenza B virus, respectively. By providing a plurality of such detection sections (d), it is possible to simultaneously immunoassay a plurality of types of substances to be detected.

[0049] In the above immunochromatographic method, a non-specific reaction suppressing component for suppressing false negatives may be included in the specimen extraction solution for mixing with the specimen and extracting the analyte, or a non-specific reaction suppressing component for suppressing false negatives may be included in the nitrocellulose membrane (i), the labeled body part (ii), and / or the sample addition part (iii) of the test device for the immunochromatographic method.

[0050] The present invention includes a test reagent that utilizes an antigen-antibody reaction or a binding reaction between substances having an interaction. The test reagent may refer to the test device itself, or may refer to a test kit including the test device and other reagents. The test reagent of the present invention includes, for example, a test kit including an immunochromatographic test device and a specimen extraction solution containing a non-specific reaction suppressing component for suppressing false negatives. Further, the test reagent of the present invention includes an immunochromatographic test device having a part containing a specimen extraction solution containing a non-specific reaction suppressing component for suppressing false negatives.

Example

[0051] The present invention will be specifically described by the following examples, but the present invention is not limited by these examples.

[0052] In the following examples, examples in which non-specific reactions in specimens are suppressed in an immunochromatographic kit for detecting influenza virus, RSV, adenovirus, and mycoplasma when using the specimen extraction solution of the present invention will be described.

[0053] Detection of influenza virus antigen by immunochromatographic method 1. Preparation of anti-influenza virus monoclonal antibody (1) Anti-influenza A virus NP (nucleoprotein) antibody The spleen was removed from BALB / c mice immunized with influenza A virus antigen and reared for a certain period, and then fused with mouse myeloma cells (P3×63) by the method of Kohler et al. (Kohler et al., Nature, vol. 256, p495-497 (1975)). The obtained fused cells (hybridomas) were maintained in a 37°C incubator, and cell purification (single cloning) was performed while confirming the antibody activity in the supernatant by ELISA using a plate immobilized with influenza A virus NP antigen. Two strains of the obtained cells were intraperitoneally administered to pristane-treated BALB / c mice, and about 2 weeks later, ascites containing antibodies was collected. IgG was purified from the obtained ascites by affinity chromatography using a protein A column, and two types of purified anti-influenza A virus NP antibodies were obtained. (2) Anti-influenza B virus NP antibody Using influenza B virus antigen, two types of purified anti-influenza B virus NP antibodies were obtained in the same manner as in (1).

[0054] 2. Preparation of the labeled body pad One type each of the purified anti-influenza A virus NP antibody and the purified anti-influenza B virus NP antibody were used. The anti-influenza A virus antibody was covalently bound to red latex particles, suspended in a suspension, and sonicated to prepare a well-dispersed anti-influenza A latex suspension. Similarly, an anti-influenza B latex suspension in which the anti-influenza B virus antibody was covalently bound to blue latex particles was prepared. The anti-influenza A latex suspension and the anti-influenza B latex suspension were mixed, applied to a glass fiber with a size of 20 cm × 1 cm, and dried well under warm air to prepare a labeled body pad forming a dry mixture.

[0055] 3. Preparation of the sample addition pad Glass fiber with a size of 2.0 cm × 20 cm was used.

[0056] 4. Preparation of the test device The inspection device used was of the same configuration as that shown in Fig. 1. A nitrocellulose membrane was cut into a size of 2 cm × 20 cm and backed with a plastic plate with an adhesive. An amount of anti-influenza A virus antibody (a different antibody from the above) solution with a width of about 1 mm was applied at positions 0.8 cm and 1.0 cm from the lower end, and an amount of anti-influenza B virus antibody (a different antibody from the above) solution was each applied for 20 cm. It was dried well under warm air to immobilize the antibody (detection part). Next, a filter paper with a size of 3 cm × 20 cm was overlapped with the upper end of the nitrocellulose membrane by 5 mm to provide an absorption pad part. Further, a labeled body pad was overlapped with the lower end of the nitrocellulose membrane by 2 mm to provide a labeled body part. Further, a sample addition pad was overlapped at a position 7 mm away from the upper end of the labeled body pad to provide a sample addition part. Then, an inspection device integrated by cutting into strips with a width of 5 mm using a cutter was produced.

[0057] Detection of RS virus, adenovirus, and Mycoplasma pneumoniae antigen by immunochromatography 1. Preparation of anti-RS virus, anti-adenovirus, and anti-Mycoplasma pneumoniae monoclonal antibodies RS virus antigen, or adenovirus antigen, or Mycoplasma pneumoniae antigen was independently immunized into BALB / c mice, and the spleen was removed from the mice reared for a certain period. It was fused with mouse myeloma cells (P3×63) by the method of Kohler et al. (Kohler et al., Nature, vol. 256, p495 - 497 (1975)). The obtained fused cells (hybridomas) were maintained in a 37°C incubator, and the cells were purified (cloned) while confirming the antibody activity of the supernatant by ELISA using plates on which each of the above antigens was immobilized. Two strains of the obtained cells were each intraperitoneally administered to pristane-treated BALB / c mice, and about 2 weeks later, ascites containing antibodies was collected. IgG was purified from the obtained ascites by affinity chromatography using a protein A column, and two purified anti-immunogen antibodies were obtained for each immunogen.

[0058] 2. Preparation of the labeled body pad Each purified anti-immunogen antibody was covalently bonded to red latex particles, suspended in a suspension, and sonicated to prepare an anti-RS virus latex suspension, an anti-adenovirus latex suspension, and an anti-pneumonia mycoplasma latex suspension that were sufficiently dispersed and suspended. These latex suspensions were each applied to glass fibers sized 20 cm × 1 cm and dried well under warm air to form a labeled body pad that was a dried mixture.

[0059] 3. Preparation of sample addition pad Glass fibers sized 2.0 cm × 20 cm were used.

[0060] 4. Preparation of test device The test device used was of the same configuration as that shown in Fig. 1. A nitrocellulose membrane was cut to a size of 2 cm × 20 cm and backed with an adhesive plastic plate. An anti-RS virus antibody (a different antibody from the above), or an anti-adenovirus antibody (a different antibody from the above), or an anti-pneumonia mycoplasma antibody in an amount of about 1 mm width was applied at positions 0.8 cm and 1.0 cm from the lower end and dried well under warm air to immobilize the antibody (detection part). Next, a filter paper sized 3 cm × 20 cm was overlapped 5 mm on the upper end of the nitrocellulose membrane to provide an absorption pad part. Further, the labeled body pad was overlapped 2 mm on the lower end of the nitrocellulose membrane to provide a labeled body part. Furthermore, the sample addition pad was overlapped at a position 7 mm away from the upper end of the labeled body pad to provide a sample addition part. Then, a test device integrated by cutting into strips 5 mm wide with a cutter was prepared.

[0061] 5. Preparation of specimen extract It is described in each of the following test examples.

[0062] Test Example 1 False negative reaction inhibitory effect of specimen extract containing L-phenylalanine (L-Phe) 1-1. Preparation of specimen extract A mixture containing 50 mM Tris buffer (pH 8.0), 2 (w / v)% polyoxyethylene octylphenyl ether, and 5 (w / v)% L-arginine was prepared and used as the specimen extract for Control 1. Next, a mixture containing 50 mM Tris buffer (pH 8.0), 1.25 (w / v)% polyoxyethylene alkyl ether, 0.75 (w / v)% polyoxyethylene octylphenyl ether, 4 (w / v)% glycine ethyl ester, 2.0 (w / v)% L-Phe, and 400 mM sodium bromide was prepared and used as the specimen extract for Test 1.

[0063] 1-2. Test method Saliva collected with a cotton swab was suspended and dispersed in the specimen extract for control 1 and the specimen extract for test 3, and then filtered. 2 Samples were prepared by adding PFU / mL of inactivated influenza A virus and mixing them, and these were dropped into the test device prepared above. After 5 minutes, the color intensity of the detection area was measured. At the same time, samples of Control 1 and Test 1 to which no saliva had been added were also measured, and 6.8 x 10 2 A test was also conducted by adding only PFU / mL of inactivated influenza virus type A. The color intensity was measured using a red color sample with a score on a 10-point scale.

[0064] 1-3. Coloring strength test results The results are shown in Table 1. The color intensity values increased in the order of 0, 1+, 2+, 10+, with 0 indicating no color development and higher values indicating a stronger false negative reaction.

[0065] In the specimen extract for Control 1, the signal intensity was reduced by 2 levels when comparing the presence and absence of saliva. On the other hand, in the specimen extract for Test 3, no difference in signal intensity was observed between the presence and absence of saliva, demonstrating that the present invention can suppress false negative reactions.

[0066] [Table 1]

[0067] Test Example 2 False-negative suppression effect of the specimen extraction solution containing L-Phe in the detection of RSV by immunochromatography 2-1. Preparation of specimen extraction solution A mixed solution containing 50 mM Tris buffer (pH 8.0), 2 (w / v)% polyoxyethylene octylphenyl ether, and 5 (w / v)% L-arginine was prepared as the specimen extraction solution for Control 1. Next, a mixed solution containing 1.5 (w / v)% L-Phe, 50 mM Tris buffer (pH 8.0), 1.25 (w / v)% polyoxyethylene alkyl ether, 0.75 (w / v)% polyoxyethylene octylphenyl ether, 4 (w / v)% glycine ethyl ester, and 150 mM sodium bromide was prepared as the specimen extraction solution for Test 4.

[0068] 2-2. Test method Saliva specimens were collected from the oral cavity with cotton swabs, and the saliva specimens were suspended and dispersed in the specimen extraction solutions for the control and Test 4. Inactivated RSV was added to each of these at 3.5 x 10 4 TCID 50 / mL and mixed to obtain the samples for this test. Also, samples were prepared by adding only inactivated RSV at 3.5 x 10 4 TCID 50 / mL to the specimen extraction solutions for the control and Test 4 without adding saliva. Next, these samples were dropped onto the test device prepared above, and the color development intensity of the detection part was measured after 5 minutes. The measurement of the color development intensity was performed using a color scale with scores assigned to 10 levels of color development intensity for both red and blue.

[0069] 2-3. Results of color development intensity test The results are shown in Table 2. The numerical values of the color development intensity increase in the order of 0, 1+, 2+ ··· 10+, where 0 indicates that no color development was observed, and the higher the numerical value, the stronger the signal.

[0070] In the control specimen extract, the addition of the saliva specimen causes a decrease in the coloring intensity due to a false negative reaction. However, in the specimen extract of Test No. 4, even when saliva is added, there is no change in the coloring intensity, indicating that false negative results caused by saliva are suppressed in the specimen extract containing the components of the present invention.

[0071]

Table 2

[0072] Test Example 3 Sensitivity Comparison between Specimen Extract Containing L-Phe and Conventional Specimen Extract

[0073] 3-1. Preparation of Specimen Extract A mixed solution containing 50 mM Tris buffer (pH 8.0), 2 (w / v)% polyoxyethylene octylphenyl ether, and 5 (w / v)% L-arginine was prepared as the specimen extract for Control No. 1. Next, a mixed solution containing 50 mM Tris buffer (pH 8.0), 1.25 (w / v)% polyoxyethylene alkyl ether, 0.75 (w / v)% polyoxyethylene octylphenyl ether, 4 (w / v)% glycine ethyl ester, 1.5 (w / v)% L-Phe, and 150 mM sodium bromide was prepared as the specimen extract for Test No. 1.

[0074] 3-2. Test Method Samples were prepared by adding inactivated influenza virus type A with final concentrations of 6.8 x 10 2 PFU / mL, 3.4 x 10 2 PFU / mL, and 1.7 x 10 2 PFU / mL to the specimen extracts of Control No. 1 and Test No. 1, respectively. Similarly, for inactivated influenza virus type B, samples were prepared by adding it with final concentrations of 4.0 x 10 2 PFU / mL, 2.0 x 10 2 PFU / mL, and 1.0 x 10 2Samples were prepared to be at a concentration of PFU / mL. Next, 50 μL of these samples was dropped onto the test device prepared above, and the color development intensity of the detection part was measured 5 minutes later. The measurement of the color development intensity was performed using a color sample scored for 10 levels of color development intensity in each of red and blue.

[0075] 3-3. Results of the color development intensity test The results are shown in Table 3. The numerical values of the color development intensity increase in the order of 0, 0.5+, 1+, 2+ ··· 10+, where 0 indicates that no color development was observed, and the higher the numerical value, the stronger the signal. The results are expressed as "color development intensity of type A / color development intensity of type B".

[0076] The sensitivity was equivalent between the sample extract of Control 1 and the sample extract of Test 1. Regarding the signal intensity, Test 1 was higher. From the above, it can be seen that by using the sample extract used in the present invention, the specificity can be improved without reducing the sensitivity.

[0077]

Table 3

[0078] Test Example 4 False negative suppression effect of sample extraction containing L-Phe analog substances

[0079] 4-1. Preparation of sample extract A mixed solution containing 50 mM Tris buffer (pH 8.0), 2 (w / v)% polyoxyethylene octylphenyl ether, and 2 (w / v)% L-arginine was prepared as a sample extract for control (without additives). Next, a sample extract containing 50 mM Tris buffer (pH 8.0), 2 (w / v)% polyoxyethylene octylphenyl ether, 2 (w / v)% L-arginine, and containing one kind of the compound in Table 4 (the concentration in parentheses) in addition to these compositions was prepared as a sample extract for testing.

[0080]

Table 4

[0081] 4-2. Test Method Saliva negative for influenza virus and RSV virus in which a false negative reaction was observed in the control specimen suspension was collected with a cotton swab. These specimens were suspended and dispersed in the control and each test specimen extraction solution to obtain samples for this test. Furthermore, influenza A virus with a final concentration of 6.8 x 10 2 PFU / mL, or influenza B virus with a final concentration of 4.0 x 10 PFU / mL, or RSV virus antigen with a final concentration of 3.5 x 10 4 TCID 50 / mL was added and mixed. Next, these samples were dropped onto each test device prepared above, and the color development intensity of the detection part was measured after 5 minutes. The measurement of the color development intensity was performed using a color sample scored for 10 levels of color development intensity to confirm the degree of suppression of false negativity.

[0082] 4-3. Color Development Intensity Test Results The results are shown in Tables 5 and 6. In the result notation, "×" indicates no effect, "△" indicates a slight improvement effect, "〇" indicates a fairly good improvement effect, and "◎" indicates a strong improvement effect. In the influenza virus detection reagent, it was expressed as "Influenza A / Influenza B".

[0083] In the RSV virus detection reagent, a false negative suppression effect could be confirmed for almost all the compounds tested, and in the influenza virus detection reagent, a false negative suppression effect could also be confirmed for a plurality of compounds.

[0084]

Table 5

[0085]

Table 6

Industrial Applicability

[0086] The method of the present invention can be used for the accurate detection of a variety of substances. [Explanation of symbols]

[0087] Nitrocellulose membrane B. Marked body part C. Detection unit D. Sample addition section E. Absorbent pad section F plastic plate

Claims

1. An inspection reagent for detecting a substance to be detected selected from the group consisting of an influenza virus antigen; an adenovirus antigen; an RS (respiratory syncytial) virus antigen; a human metapneumovirus (hMPV) antigen; a coronavirus antigen including SARS-CoV, MERS-Cov or SARS-CoV2; group A streptococcus; group B streptococcus; and a mycoplasma antigen in a specimen selected from the group consisting of a throat swab specimen, a nasal swab specimen, a nasal aspirate specimen, a nasal wash specimen, a nasal mucus specimen and a saliva specimen, which utilizes a binding reaction between substances having an antigen-antibody reaction or interaction, and contains a specimen extract containing a non-specific reaction suppressing component that suppresses false negatives and is a compound selected from the group consisting of L-phenylalanine, D-phenylalanine, hippuric acid, mandelic acid, N-phenylglycine, 3-phenylpropionic acid, N-(m-toluoyl)glycine and L-tryptophan.

2. The inspection reagent according to claim 1, wherein the specimen extract contains a non-specific reaction suppressing component that suppresses false negatives at 0.1 to 10 (w / v)%.

3. The inspection reagent according to claim 1 or 2, wherein the specimen extract further contains an amino acid or an amino acid derivative selected from the group consisting of arginine, lysine, arginine ethyl ester, arginine methyl ester, glycine ethyl ester and glycine methyl ester, and optical isomers, geometric isomers, structural isomers and stereoisomers of these compounds.

4. The inspection reagent according to any one of claims 1 to 3, wherein the specimen extract further contains a halide selected from the group consisting of lithium chloride, sodium chloride, potassium chloride, sodium bromide, potassium bromide, sodium iodide and potassium iodide.

5. A method for detecting a substance to be detected selected from the group consisting of an influenza virus antigen, an adenovirus antigen, an RS (respiratory syncytial) virus antigen, a human metapneumovirus (hMPV) antigen, a coronavirus antigen including SARS-CoV, MERS-Cov or SARS-CoV2, group A streptococcus, group B streptococcus, and a mycoplasma antigen in a specimen selected from the group consisting of a throat swab specimen, a nasal swab specimen, a nasal aspirate specimen, a nasal wash specimen, a nasal mucus specimen, and a saliva specimen, by utilizing a reaction between substances having an antigen-antibody reaction or interaction contained in the specimen extract. In this method, the specimen is preliminarily contacted with a non-specific reaction suppressing component, which is a compound selected from the group consisting of L-phenylalanine, D-phenylalanine, hippuric acid, mandelic acid, N-phenylglycine, 3-phenylpropionic acid, N-(m-toluoyl)glycine, and L-tryptophan, to suppress false negative reactions for detection.

6. The method according to claim 5, wherein the method for detecting the substance to be detected is an immunochromatographic method.

7. The method according to claim 5 or 6, wherein the specimen extract contains a non-specific reaction suppressing component that suppresses false negatives at 0.1 to 10 (w / v)%.

8. The method according to any one of claims 5 to 7, wherein the specimen extract further contains an amino acid or amino acid derivative selected from the group consisting of arginine, lysine, arginine ethyl ester, arginine methyl ester, glycine ethyl ester, glycine methyl ester, and optical isomers, geometric isomers, structural isomers, and stereoisomers of these compounds.

9. The method according to any one of claims 5 to 8, wherein the specimen extract further contains a halide selected from the group consisting of lithium chloride, sodium chloride, potassium chloride, sodium bromide, potassium bromide, sodium iodide, and potassium iodide.

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