JP2008189613A - Method for stabilizing antibody, immunochromatography process using the method and kit for diagnosing plant virus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for stabilizing an antibody by using a tripeptide having a specific structure and to provide an immunochromatography process using the method and a kit for diagnosing a plant virus. <P>SOLUTION: The method for stabilizing an antibody comprises adding a tripeptide (β-Ala-Orn-Orn) having a peptide bond in the order of β-alanine, ornithine and ornithine from an N terminal to the medium of an antibody or a composition containing an antibody. In the immunochromatography process for plant virus detection, the tripeptide as an antibody stabilizer is added to a mobile phase medium containing a plant virus antibody. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an antibody stabilization method, an immunochromatography method using the method, and a plant virus diagnostic kit. In particular, as a stabilizer, a specific amino acid sequence in which peptides are bound in the order of β-alanine, ornithine, ornithine from the N-terminus. The present invention relates to a method for stabilizing an antibody characterized by using a tripeptide having, an immunochromatography method using the method, and a plant virus diagnostic kit.

  By using a specific reaction between an antigen and an antibody, it is possible to detect or quantify the antigen (target substance) with high accuracy. Clinical diagnosis and food analysis using the antigen-antibody reaction Environmental analysis is widely performed. However, since antibodies have low storage stability and have the drawback that when they are stored at room temperature, the reactivity with the antigen is significantly reduced, storage in a solution is generally carried out exclusively by freezing or refrigeration. In addition, an immunochromatography method can be used as a method for easily determining the presence or absence of an antigen, and the immunochromatography method can also be used for detection of plant viruses. Plant virus disease is a difficult disease to control, and early diagnosis and early removal have been the basic measures. The fact is that there is no end to it. Moreover, the occurrence of a new virus that seems to have entered from overseas has been reported every year. Among them, the technology of pest diagnosis occupies an important position in production, but knowledge and experience are required for accurate diagnosis.

Now, the inventors of the present application use a tripeptide (hereinafter, also referred to as “β-Ala-Orn-Orn”) in which β-alanine, ornithine and ornithine are linked in this order from the N-terminal as a protein stabilizer. It has been found that it is effective and has already filed a patent application (patent document 1 unpublished at the time of filing this application). The outline is as follows.
[I] Reagent composition comprising a peptide having a peptide bond in the order of β-alanine and ornithine from the N-terminal, or ornithine and ornithine in the order of the N-terminal or a salt thereof, and at least one of a protein and a protein-binding carrier A method for stabilizing a protein, characterized by coexisting with a product.
[Ii] A protein stabilizer comprising a peptide or a salt thereof having a peptide bond sequence in the order of β-alanine and ornithine from the N terminus, ornithine and ornithine in the order of the N terminus.
[Iii] A protein stabilizer comprising a dipeptide having a peptide bond in the order of β-alanine and ornithine, or a dipeptide having a peptide bond in the order of ornithine and ornithine or a salt thereof.
[Iv] A reagent composition comprising a peptide having a peptide bond in the order of β-alanine and ornithine from the N-terminal, or ornithine and ornithine in the order of the N-terminal, or a salt thereof, and at least one of a protein and a protein-binding carrier. A protein-containing solution characterized by coexisting with a product.
[V] A biological component measuring reagent using the protein-containing solution according to [iv].
[Vi] A standard solution used for biological component measurement using the protein-containing solution according to [iv].

Prior to that, the inventors have already filed a method for producing the tripeptide from a swordfish extract (Patent Document 2). That is, it is a method of diluting a swordfish extract with water and fractionating. The patent application also discloses a chemical synthesis method using ornithine in which an α-amino group and a δ-amino group are protected and β-alanine in which a β-amino group is protected. Furthermore, a method for producing the tripeptide in the presence of ATP and Mg ²⁺ using β-alanine and ornithine itself, both of which are not chemically modified, using an enzyme that can be extracted from the tissue constituting similar meat, has already been disclosed. Has been filed (patent document 3 unpublished at the time of filing this application). On the other hand, for detection of plant viruses by immunochromatography, a chromatographic medium comprising a filter paper having a reaction site containing an antibody that binds to a plant body or a trace component present on the surface of the plant body as an immobilizing reagent is used. The chromatographic medium is brought into contact with a test liquid consisting of a crude body fluid and a dispersion of colored particles carrying an antibody that binds to the trace substance until the reaction site is reached. A method for inspecting a trace substance in a plant or on the surface of a plant characterized by observing a colored state caused by aggregation of the colored particles, which is caused by an antibody binding to a trace substance bound to an immobilized reagent at a reaction site. Has already been proposed (Patent Document 4).

Japanese Patent Application No. 2005-239715 “Protein Stabilization Method, Protein Stabilizer, and Protein-Containing Solution” (Unpublished at the time of filing this application) JP-A 2005-200377 “Novel Tripeptide and Method for Producing the Same” Japanese Patent Application No. 2006-256218 “Tripeptide Synthesis Method, Peptide Synthase Preparation Method, and Peptide Synthase” (not disclosed at the time of filing this application) Patent No. 2500335 “Method for detecting trace substances in plants or on plant surfaces”

  The applicants of the present application have developed an immunochromatography method using protein A adsorbent-type antibody-sensitized latex by applying the invention of Patent Document 4 to the plant virus detection technology in the past research, and with high sensitivity. Moreover, plant viruses can be diagnosed quickly. That is, using a chromatographic medium composed of a filter paper having a reaction site containing an antibody that binds to a virus present on a plant body or a plant body surface as an immobilizing reagent, a test liquid comprising a crude liquid of the test target plant, and the above The chromatographic medium is brought into contact with a dispersion of colored particles carrying an antibody that binds to a virus and developed until reaching the reaction site, and the antibody is detected against a trace substance bound to the immobilized reagent at the reaction site of the chromatographic medium. A method for examining a plant virus, characterized by observing a color development state caused by aggregation of the colored particles, which is caused by binding of.

  This immunochromatography method was aimed at enabling anyone to diagnose plant virus infection easily and reliably in an outdoor environment such as a field. However, in reality, if a dispersion of colored particles carrying an antibody that binds to the target plant virus (hereinafter also referred to as “mobile phase”) is stored at room temperature, the reactivity with the antibody is significantly reduced. It was necessary to always keep the reagent in the refrigerator. In the outdoor environment, this required not only a container for refrigeration, such as a cooler box, but also the fact that this kit could not be marketed at room temperature, which was a major obstacle to sales. Furthermore, even when stored refrigerated, it is difficult to maintain stability for several months, so it is not possible to have inventory, and it is necessary to respond to made-to-order production, so it is extremely inefficient in manufacturing Incurs high product costs. Therefore, in order to commercialize the developed immunochromatography method, a method for stabilizing an antibody that can withstand storage at room temperature has been strongly demanded.

  The problem to be solved by the present invention is a method for stabilizing an antibody that can withstand storage for 6 months at least at 24 ° C. (room temperature is assumed), excluding the problems of the prior art. And an immunochromatography method using the method and a plant virus diagnostic kit.

  As a result of studying the above problems, the present inventors have demonstrated that a tripeptide peptide-bonded in the order of β-alanine, ornithine and ornithine from the N-terminus has a high stabilizing effect on the antibody, and the method was immunochromatographed. As a result of application to the method, it became clear that stability that can withstand storage for 6 months or longer at 24 ° C. assuming room temperature was obtained, and based on this, the present invention was achieved. That is, the invention claimed in the present application, or at least the disclosed invention, as means for solving the above-described problems is as follows.

(1) A method for stabilizing an antibody, which comprises containing an antibody or a tripeptide peptide-bound in the order of β-alanine, ornithine, ornithine from the N-terminus in a medium of an antibody-containing composition.
(2) In an immunochromatography method using a mobile phase medium containing a plant virus antibody and a stationary phase for detection of a plant virus, peptide binding in the order of β-alanine, ornithine, ornithine from the N-terminal to the mobile phase medium An immunochromatographic method characterized in that the prepared tripeptide is contained as an antibody stabilizer.
(3) A plant virus diagnostic kit comprising a chromatographic medium on which an antibody of the plant virus is immobilized and a mobile phase medium containing the antibody in order to detect a specific plant virus. A plant virus diagnostic kit comprising a tripeptide in which β-alanine, ornithine and ornithine in the order of β-alanine and ornithine are bound as an antibody stabilizer.
In other words, the present invention is novel in that the storage stability of an antibody can be remarkably enhanced by allowing an antibody or a composition containing an antibody to coexist with a tripeptide having a peptide bond in the order of β-alanine, ornithine, ornithine from the N-terminus. Technology is the foundation.

  In the above Patent Document 2, the inventors of the present invention have clarified that a tripeptide in which β-alanine, ornithine and ornithine in the order of β-alanine, ornithine are combined in this order is effective as a protein stabilizer. Only the stabilizing effect of (lysozyme) on heat treatment is described. The present invention is directed to antibodies, and utilizes the high stabilizing effect of the tripeptide on antibodies.

  According to the present invention, an antibody can be stabilized by containing a tripeptide (β-Ala-Orn-Orn) in the medium of the antibody or a composition containing the antibody. In the immunochromatography method using a mobile phase medium containing a plant virus antibody and a stationary phase for the detection of a plant virus, the antibody can be stabilized by containing the tripeptide in the mobile phase medium. It is possible to provide an immunochromatography method that can withstand storage for 6 months or more at an assumed 24 ° C. Furthermore, in order to detect a specific plant virus, in a plant virus diagnostic kit comprising a chromatographic medium on which an antibody of the plant virus is immobilized and a mobile phase medium containing the antibody, the mobile phase medium contains the mobile phase medium. An antibody can be stabilized by containing a tripeptide, and it becomes possible to provide a plant virus diagnostic kit that can withstand storage at 24 ° C. for 6 months or more assuming room temperature. This eliminates the need for complicated refrigerated storage during production, distribution, and use of plant virus diagnostic kits.

Hereinafter, the present invention will be described in more detail.
A tripeptide having a specific structure (β-Ala-Orn-Orn) can be obtained by purification from a shijimi extract, chemical synthesis, or enzymatic synthesis. The tripeptide or a salt thereof used in the antibody stabilization method of the present invention is a tripeptide having a sequence in which β-alanine, ornithine and ornithine are peptide-bonded in this order from the N-terminus. The antibody, enzyme-labeled antibody, and fluorescent label By containing the tripeptide in an antibody composition containing at least one of antibodies, colloidal gold antibodies, antibodies adsorbed on magnetic beads, or those bound to a carrier, the antibody can be stabilized. To get.

  Further, the concentration of the tripeptide at the time of use is preferably optimized depending on the antibody concentration and other component contents in the reagent composition used by mixing, and is preferably used in the range of 0.1 mM to 10 mM. Although it can, it is not limited to this range.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.
<Example 1 Stabilizing effect of tripeptide (β-Ala-Orn-Orn) on antibody in antigen-antibody reaction>
In the reactivity of rabbit IgG with horseradish peroxidase (HRP) -labeled goat anti-rabbit IgG antibody, the tripeptide was added to the horseradish peroxidase (HRP) -labeled goat anti-rabbit IgG antibody solution to thereby produce the same antibody of the tripeptide. The stabilization effect against was investigated.
(1) Preparation method and preservation test method of horseradish peroxidase (HRP) -labeled goat anti-rabbit IgG antibody solution The test substance (stabilizer) described in Table 1 was added in 0.15 mol / l (liter) sodium chloride, 0. It was dissolved in 50 mmol / l Tris-HCl buffer (pH 7.5) (hereinafter referred to as P-TBS) containing 05% Tween 20 and 0.05% procrine 300 as a preservative, and adjusted to the set concentration. A solution filtered through a 22 μm filter was used as a test substance solution. A solution obtained by diluting horseradish peroxidase (HRP) -labeled goat anti-rabbit IgG antibody (hereinafter referred to as HRP-goat anti-rabbit IgG antibody) (CHEMICON INTERNATIONAL) 10,000 times with the above test substance solution was used for the storage test. On the day of the test, the activity (stability) of the HRP-goat anti-rabbit IgG antibody after 1 week, 3 weeks, 6 weeks and 12 weeks after storage at 37 ° C. was examined. Each test solution was returned to room temperature (20-25 ° C.) before measurement and used for activity measurement.

(2) Method for measuring activity of HRP-goat anti-rabbit IgG antibody P-TBS containing 1% BSA in each well of a solid-phased goat anti-rabbit IgG antibody plate (Reacti-Bind ^™ Goat Anti-Rabbit IgG Coated Plates, PIERCE) (Hereinafter referred to as the BSA solution) was added in an amount of 100 μl, and then 20 μl of rabbit IgG (CHEMICON INTERNIONALAL) adjusted to 100 ng / ml with the BSA solution was added (blank is the BSA solution) and allowed to stand at 37 ° C. for 60 minutes. The antigen-antibody reaction was performed.

After completion of the reaction, each well was washed four times with P-TBS, 100 μl of HRP-goat anti-rabbit IgG antibody solution used for the storage test as described above was added, and the mixture was allowed to stand at 37 ° C. for 60 minutes for antigen-antibody reaction. It was. After completion of the reaction, each well was washed 4 times with P-TBS, and 100 μl each of tetramethylbenzidine solution (SureBlue ^™ TMB Microwell Peroxidase Substrate, KPL) was added as a peroxidase substrate, reacted at 37 ° C. for 30 minutes, and colored blue I let you. After 30 minutes, when 100 μl of 1N HCl was added to each well to stop the reaction, the color changed from blue to yellow, and the absorbance at a wavelength of 450 nm was measured with a microplate reader (iEMS Reader MF, Dainippon Pharmaceutical).

  The stability of HRP-goat anti-rabbit IgG antibody was evaluated by measuring the residual activity of peroxidase. The residual activity of peroxidase was expressed as a percentage (%) of the ratio of the absorbance measured using the test solution subjected to the storage test to the absorbance measured using the sample on the test solution preparation day. The measurement wavelength is 450 nm. The higher the residual activity of peroxidase, the higher the stabilization effect of the test substance against the antibody.

(3) Results Table 1 shows the results of the peroxidase residual activity in each test substance. When stored at 37 ° C. for 1 week, the residual activity of the HRP-goat anti-rabbit IgG antibody was 28% without addition and 65% with addition of BSA, and the activity decreased. On the other hand, with the tripeptide (1 mM) according to the present invention, the residual activity was 100%, and no decrease in activity was observed. The tripeptide showed a high residual activity even when stored for 3 weeks or 6 weeks, and when stored for 12 weeks, the residual activity of the HRP-goat anti-rabbit IgG antibody was 1% without addition and 14% with addition of BSA. %, The tripeptide according to the present invention (1 mM) still had a high residual activity of 50%, indicating a very good stabilizing effect. In addition, arginine ethyl ester (1 mM), which has been known to have a protein stabilizing effect, has a residual activity of 1% after 6 weeks. No stabilizing effect was observed below.

<Example 2 Stabilizing effect of tripeptide (β-Ala-Orn-Orn) on antibody in immunochromatography>
We examined the stabilization effect of the tripeptide against antibodies in immunochromatography using a cucumber mosaic virus (CMV), a plant virus, as an antigen and CMV antiserum prepared by inoculating rabbits with the virus. .

(1) Preparation method of protein A adsorption type antibody-sensitized latex medium Protein A adsorption type antibody sensitized latex medium was prepared by immobilizing white latex (Immutex S080-02-120, Nippon Organic Synthetic Rubber ( Co., Ltd.) using a pink latex (Imutex G0304CR, Nippon Organic Synthetic Rubber Co., Ltd.) for detection, and an equal amount of 0.5% white latex medium or protein A solution (Nacalai) prepared to 100 μg / ml After mixing 1% pink latex medium and shaking at 160 rpm for 2 hours at room temperature, a precipitate was obtained by centrifugation at 10,000 * g for 10 minutes. Suspend in washing buffer (0.05M Tris-HCl buffer, pH 7.0 containing 0.45% NaCl and 0.1% calf serum albumin (BSA)), and repeat the centrifugation / suspension operation four times. Add an equal volume of CMV antiserum diluted 50 to 100-fold with washing buffer and mix with suspended white protein A latex medium or pink protein A latex medium and let stand at 4 ° C overnight. I put it. The washing operation described above was performed, and finally, the suspension was suspended in 1 ml of a washing buffer solution to obtain a white protein A adsorption type antibody sensitized latex medium or a pink protein A adsorption type antibody sensitized latex medium.

(2) Method for preparing stationary phase The stationary phase in the immunochromatography method was prepared as follows. Glass fiber filter paper GF / A (Whatman) was used as the immunochromatography detection filter paper, and glass fiber filter paper GA100 (Advantec) was overlaid on top of the filter paper as a filter paper for solution absorption. A white protein A adsorption type antibody-sensitized latex medium for immobilization is streaked with a 1 mm width using a face brush at a position of 17 to 18 mm from the lower side of the detection filter paper so as to be 15 to 20 μl per cm of the filter paper width. Then, it was fixed by adsorption and dried. The lower side of the detection filter paper was aligned and pasted at a position 1 mm from the end of the white PPC label sheet (KOKUYO), and further 5 mm from the lower end of the detection filter paper was placed on and covered with a transparent PPC label sheet (KOKUYO). The produced stationary phase was cut to a width of 5 to 10 mm and stored in a desiccator at room temperature.

(3) Preparation method of mobile phase test solution The test substance (stabilizing agent) shown in Table 2 is dissolved in a pink protein A-adsorbing antibody-sensitized latex medium for detection and adjusted to a set concentration. A test solution was obtained. The mobile phase test solution is allowed to stand in a 5 ° C. refrigerator and a 24 ° C. incubator, and on the test day, after 2 weeks, 1 month, 2 months, 3 months, 6 months, 10 months, and 12 months. The activity (reactivity) was measured and the stabilization effect of the test substance was evaluated. The temperature setting of 24 ° C. assumes room temperature storage.

(4) Activity measurement method of mobile phase (pink protein A adsorption-type antibody-sensitized latex medium for detection) Immobilized white by absorbing and developing 100 μl of CMV solution prepared to 100 μg / ml on the stationary phase prepared above. Immediately after the latex antibody reacts with the antigen-antibody, 100 μl of a mobile phase test solution containing a stabilizing agent that has been subjected to a storage test (pink protein A adsorption-type antibody-sensitized latex medium for detection) is absorbed and spread on a filter paper. It was. The presence or absence of pink colored lines on the filter paper caused by the antigen-antibody reaction of CMV and pink protein A adsorbent antibody-sensitized latex particles bound to the antibody of immobilized white latex particles on the filter paper for several minutes. The shade was compared with the degree of coloring of the mobile phase that was not prepared as a control, and the reactivity of the antibody contained in the mobile phase was evaluated.

  The results of the storage test at 5 ° C. are shown in Table 2. The mobile phase test solution without the addition of a stabilizer showed a weak reaction until 3 months later. The mobile phase test solution to which arginine ester was added showed a very weak reaction until 2 months of storage, a very weak reaction after 3 months of storage, and no reaction after 6 months.

  On the other hand, the mobile phase test solution containing 2 mM of the tripeptide stored at 5 ° C. showed a reaction even after 12 months, and the tripeptide according to the present invention showed a high stabilizing effect on the antibody. It was.

  Table 3 shows the results of the storage test at 24 ° C. In the mobile phase test solution to which no stabilizer was added and arginine ester was added, the reaction became extremely weak after 2 weeks and no reaction was observed after 1 month. On the other hand, the mobile phase test solution in which 2 mM of the tripeptide stored at 24 ° C. coexisted showed a reaction even after 12 months, and showed a high stabilizing effect on the antibody in the tripeptide.

<Example 3 Stabilizing effect of tripeptide (β-Ala-Orn-Orn) on antibody in plant virus diagnostic kit using immunochromatography>
In an immunochromatography method using as an antibody a CMV antiserum prepared by inoculating a rabbit with the cucumber mosaic virus (CMV), which is a kind of plant virus, in the rabbit, the plant virus using the above tripeptide as its mobile phase A diagnostic kit was prepared, and the stabilization effect of the tripeptide on the antibody was examined.

(1) Preparation method of protein A adsorption type antibody sensitized latex used in plant virus diagnostic kit Preparation of protein A adsorption type antibody sensitized latex medium was carried out in the same manner as in Example 2. White latex (Immutex S080-02-120, Nippon Organic Synthetic Rubber Co., Ltd.) was used for immobilization of immunochromatography detection filter paper, and pink latex (Immutex G0304CR, Nippon Organic Synthetic Rubber Co., Ltd.) was used for detection, and 100 μg / The protein A solution (Nacalai) prepared in ml and an equal amount of 0.5% white latex medium or 1% pink latex medium are mixed, shaken at 160 rpm for 2 hours at room temperature, and then 10,000 * g, A precipitate was obtained by centrifugation for 10 minutes. Suspend in washing buffer (0.05M Tris-HCl buffer, pH 7.0 containing 0.45% NaCl and 0.1% calf serum albumin (BSA)), and repeat the centrifugation / suspension operation four times. Add an equal volume of CMV antiserum diluted 50 to 100-fold with washing buffer and mix with suspended white protein A latex medium or pink protein A latex medium and let stand at 4 ° C overnight. I put it. The washing operation described above was performed, and finally, the suspension was suspended in 1 ml of a washing buffer solution to obtain a white protein A adsorption type antibody sensitized latex medium or a pink protein A adsorption type antibody sensitized latex medium.

(2) Method for producing stationary phase in plant virus diagnostic kit The stationary phase was produced in the same manner as in Example 2. Glass fiber filter paper GF / A (Whatman) was used as the immunochromatography detection filter paper, and glass fiber filter paper GA100 (Advantec) was overlaid on top of the filter paper as a filter paper for solution absorption. A white protein A adsorption type antibody-sensitized latex medium for immobilization is streaked with a 1 mm width using a face brush at a position of 17 to 18 mm from the lower side of the detection filter paper so as to be 15 to 20 μl per cm of the filter paper width. Then, it was fixed by adsorption and dried. The lower side of the detection filter paper was aligned and pasted at a position 1 mm from the end of the white PPC label sheet (KOKUYO), and further 5 mm from the lower end of the detection filter paper was placed on and covered with a transparent PPC label sheet (KOKUYO). The prepared stationary phase was cut to a width of 5 to 10 mm and stored in a desiccator at room temperature.

(3) Preparation Method of Mobile Phase in Plant Virus Diagnostic Kit The tripeptide was dissolved in the pink protein A-adsorbing antibody-sensitized latex medium for detection prepared as described above and adjusted to 2 mM to obtain a mobile phase. The mobile phase was allowed to stand in a 24 ° C. incubator, and the reactivity on the test day, 1 month, 2 months, 3 months, 6 months, and 12 months was examined. The temperature setting of 24 ° C. assumes room temperature storage.

(4) Method for measuring activity of mobile phase (pink protein A adsorbing type antibody-sensitized latex medium for detection) in plant virus diagnostic kits On cucumber leaf pieces (about 100 mg) with clear symptom due to CMV infection, polished Add 1 ml of crushing buffer (0.1 M phosphate buffer pH 7.0 containing 0.1% 2-mercaptoethanol, 10 mM EDTA, 0.15% polyvinylpyrrolidone, 0.1% BSA), grind, After 100 μl of the obtained crude juice was absorbed and developed on the stationary phase prepared as described above and allowed to react with the immobilized white latex particles for antigen-antibody reaction, immediately, 100 μl of a pink mobile phase containing the tripeptide that had been subjected to a storage test. Was absorbed and spread on a filter paper. The presence or absence of pink colored lines on the filter paper caused by the antigen-antibody reaction of CMV and pink protein A adsorbent antibody-sensitized latex particles bound to the antibody of immobilized white latex particles on the filter paper for several minutes. The shade was compared with the degree of coloring of the mobile phase that was not prepared as a control, and the reactivity of the antibody contained in the mobile phase was evaluated.

(5) Results As a result of the storage test of the mobile phase in the plant virus diagnostic kit, a pink colored line appears even when the mobile phase is stored at 24 ° C. after 6 months and 12 months, and the activity (reactivity) is maintained. It was recognized that From this, it was found that the use of the tripeptide as an antibody stabilizer in the mobile phase can provide a plant virus diagnostic kit using an immunochromatography method that can be stored at room temperature and is sufficiently compatible with field tests. On the other hand, when the tripeptide was not used, no activity was observed after 1 month storage at 24 ° C.

It was found that a tripeptide having a specific structure (β-Ala-Orn-Orn) is effective as an antibody stabilizer. By using the tripeptide for antibody stabilization, a reagent containing an antibody that has been required to be refrigerated until now can be stored at room temperature. By applying it to the mobile phase of a plant virus diagnostic kit using the immunochromatography method, it can be sold at room temperature without refrigerated storage, and it becomes easy to bring the plant virus diagnostic kit to the field for inspection. Therefore, the invention has high industrial utility value.

Claims (3)

A method for stabilizing an antibody, which comprises containing an antibody or a tripeptide peptide-bound in the order of β-alanine, ornithine, ornithine from the N-terminal in a medium of an antibody-containing composition. In the immunochromatography method using a mobile phase medium containing a plant virus antibody and a stationary phase for detection of a plant virus, a tripeptide in which β-alanine, ornithine and ornithine are peptide-bound in this order from the N-terminal to the mobile phase medium Is contained as an antibody stabilizer, an immunochromatographic method. In order to detect a specific plant virus, a plant virus diagnostic kit comprising a chromatographic medium on which an antibody of the plant virus is immobilized and a mobile phase medium containing the antibody, wherein the mobile phase medium has an N-terminal A plant virus diagnostic kit comprising a tripeptide having a peptide bond in the order of β-alanine, ornithine and ornithine as an antibody stabilizer.