WO2025205239A1 - Composition, dry reagent, and method for preserving composition - Google Patents

Abstract

A composition according to one aspect of the present disclosure comprises: a reaction component which reacts with a target component that is contained in a biological sample and that is a target for measurement; trehalose; and water. The composition contains 0.2-90 wt% of trehalose and 1-30 wt% of water with respect to the total weight of the composition, and the weight of the water is not more than 5 times the weight of the trehalose.

Description

Composition, dry reagent, and method for storing composition

The present invention relates to a composition, a dry reagent comprising the composition, and a method for storing the composition.

In clinical testing, biochemical research, and other fields, it is common to qualitatively or quantitatively analyze components in biological samples using optical or electrochemical detection with enzymes. Enzyme reactions are also commonly used to replicate and amplify DNA in biological samples.

When utilizing the reaction activity of an enzyme, deterioration of the enzyme's reaction activity should be avoided, as it can cause a deterioration in the performance of reagents that use the enzyme. To prevent deterioration of the enzyme's reaction activity, it is effective to dry the aqueous protein solution and store it in a solid state.

For example, Patent Document 1 discloses a dry reagent for quantitatively analyzing a specific component contained in a liquid sample, which contains a nicotinamide coenzyme and a smoothing agent for smoothing the dry reagent, and is configured so that an increase or decrease in the nicotinamide coenzyme is measured by a transmittance method using light in the ultraviolet region.

Japanese Patent Application Publication No. 2013-165709

The conventional technologies described above improve reagent stability by reducing the amount of water in the reagent. However, when considering application to slide-reagent-type dry chemistry technology, it is preferable for bound water to remain in the dried reagent. However, if moisture remains, the reagent will generally be more susceptible to deterioration. For this reason, there is a demand for technology that improves the storage stability of dried reagents while retaining bound water. Furthermore, from the perspective of improving usability, there is a demand for reagents that can be stored at room temperature.

One aspect of the present invention aims to provide a reagent composition that contains a specific amount of moisture yet has excellent storage stability.

In order to solve the above problems, a composition according to one embodiment of the present invention contains a reactive component that reacts with a target component to be measured contained in a biological sample, trehalose, and water, and contains 0.2% by weight or more and 90% by weight or less of the trehalose and 1% by weight or more and 30% by weight or less of the water relative to the total weight of the composition, and the weight of the water is 5 times or less the weight of the trehalose.

One aspect of the present invention provides a reagent composition that contains a specific amount of moisture yet has excellent storage stability.

One aspect of the present invention is described in detail below. Note that unless otherwise specified in this specification, "A to B" representing a numerical range means "greater than or equal to A and less than or equal to B."

[1. Composition]
A composition according to one embodiment of the present invention contains a reactive component that reacts with a target component to be measured contained in a biological sample, trehalose, and water, and contains 0.2% by weight or more and 90% by weight or less of the trehalose and 1% by weight or more and 30% by weight or less of the water, relative to the total weight of the composition, and the weight of the water is 5 times or less the weight of the trehalose.

This provides the following advantages. First, the composition of one embodiment of the present invention is applicable to test reagents that utilize dry chemistry technology, but because it contains a specific amount of water, it can also be applied to slide-reagent-type dry chemistry technology.

Dry chemistry refers to a dry testing method in which a test strip is prepared by forming a layer of a reagent composition containing a reactive component that reacts with the component to be measured contained in the biological sample on a support such as a slide, and then using this test strip to detect the component to be measured in the biological sample. Test reagents that utilize dry chemistry technology are useful as point-of-care testing (POCT) performed at the patient's bedside.

Next, the composition according to one embodiment of the present invention has excellent storage stability because it contains a specific amount of trehalose, which can suppress deterioration of the reactive components in the composition. This makes it possible to store a dry reagent comprising a composition according to one embodiment of the present invention at room temperature or above. A dry reagent comprising a composition according to one embodiment of the present invention will be described later.

In this specification, the term "biological sample" refers to compositions and secretions from living organisms such as animals, plants, fish, aquatic organisms, and fungi; organisms such as viruses present within such organisms; and organic and inorganic substances attached to such organisms. More specifically, it refers to the body fluids, blood, tissues inside and on the surface of the body of living organisms.

In this specification, the "component to be measured contained in a biological sample" refers to, for example, inorganic ions such as sodium in body fluids; specific proteins in body fluids; enzymes in blood; various organic compounds in blood; inorganic compounds in blood; cells; epidermis; bones; etc. The "component to be measured contained in a biological sample" may also be referred to as the "component to be measured."

As used herein, "excellent storage stability" means that when a composition according to one embodiment of the present invention is subjected to the stability evaluation test described in the Examples below, and stored at 60°C for one month, the change in absorbance measured before and after storage is within ±20%. The smaller this change, the better the storage stability; the change is preferably within ±15%, more preferably within ±10%, and even more preferably within ±5%.

<Trehalose>
A composition according to one embodiment of the present invention contains trehalose in an amount of 0.2 wt % or more and 90 wt % or less, based on the total weight of the composition. By ensuring that the trehalose content in the composition is within the above range, deterioration of the reactive components in the composition can be sufficiently suppressed, and the storage stability of the composition can be sufficiently improved.

Trehalose exists in three bond isomers: α,α-trehalose, α,β-trehalose (neotrehalose), and β,β-trehalose (isotrehalose). α,α-trehalose is sometimes simply called trehalose. The term "trehalose" used herein encompasses these three bond isomers. The trehalose contained in the composition according to one embodiment of the present invention can be any common trehalose commercially available, such as α,α-trehalose.

(Preferable Trehalose Content)
From the viewpoint of improving the storage stability of the composition according to one embodiment of the present invention, the composition preferably contains 1.0 wt% or more, and more preferably 2.0 wt% or more, of trehalose relative to 100 wt% of the composition. From the viewpoint of the solubility of trehalose, the composition preferably contains 90 wt% or less, and even more preferably 80 wt% or less, of trehalose relative to 100 wt% of the composition.

<Moisture>
A composition according to one embodiment of the present invention contains water in an amount of 1 wt % or more and 30 wt % or less relative to the total weight of the composition, and the weight of the water is 5 times or less the weight of trehalose. When the water content in the composition is within the above-mentioned range, the composition according to one embodiment of the present invention can be in a solid form that can be applied to slide-reagent-type dry chemistry techniques. Furthermore, when the weight of water relative to the weight of trehalose is within the above-mentioned range, water can be contained in the composition according to one embodiment of the present invention within a range that does not interfere with the effect of trehalose in improving the storage stability of the composition.

The water content in the composition according to one embodiment of the present invention can be adjusted to fall within the above range by adjusting the drying conditions when a solution containing the components of the composition according to one embodiment of the present invention is dried to produce a solid composition. For example, the water content in the composition can be adjusted to fall within the above range by air-drying a solution containing the components of the composition according to one embodiment of the present invention.

In this specification, the term "moisture" includes both bound water and free water present in the composition. When the moisture content of a solid composition obtained by drying a solution containing the components of a composition according to one embodiment of the present invention is greater than 1% by weight, it can be said that bound water remains in the composition. The moisture content of a composition according to one embodiment of the present invention can be measured by the method of measuring infrared (IR) spectra described in the Examples below.

(Preferable moisture content)
From the viewpoint of handleability of the dried product, the water content in the composition is preferably more than 1 wt % and more preferably 3 wt % or more relative to 100 wt % of the composition, and from the viewpoint of storage stability, the water content in the composition is preferably 30 wt % or less and more preferably 10 wt % or less relative to 100 wt % of the composition.

Furthermore, from the standpoint of storage stability, it is preferable that the weight of water be no more than five times the weight of trehalose contained in the composition.

<Reaction components>
The reactive component contained in the composition according to one embodiment of the present invention is a component that reacts with a component to be measured contained in a biological sample, and is a component that selectively uses a specific component in the biological sample as a reaction substrate to cause some kind of chemical reaction to proceed. Even when multiple components are present in a biological sample, the reactive component has the property of selectively reacting with a specific component. Specific examples of the reactive component include enzymes, catalysts, antibodies, etc.

Examples of reaction components commonly used in clinical test reagents are shown in Table 1.

The type of reactive component contained in a composition according to one embodiment of the present invention is not particularly limited and may be determined appropriately depending on the type of component to be measured.

The reaction components of a composition according to one embodiment of the present invention can include an enzyme, as well as optional substrates and dyes. The reasons for this are explained below.

(enzyme)
Enzymes are proteins, and maintaining their higher-order structure is important for maintaining their activity. The higher-order structure is maintained by the mild aggregation of constituent amino acids due to their hydrophobicity in water, hydrogen bonding between the constituent amino acids, and other factors. When enzymes are stored in a dry state, the water surrounding the enzyme is removed during drying, which removes factors that maintain these structures, causing structural reorganization (denaturation), resulting in a decrease in enzyme activity. Therefore, if a non-volatile compound that replaces the functions of water, such as hydrogen bonding and providing a hydrophilic environment, is present around or inside the protein when the enzyme is dried, the above-mentioned structural reorganization is less likely to occur, and the decrease in enzyme activity can be suppressed. As described above, the composition according to one embodiment of the present invention contains trehalose, which can function as a stabilizing component. Therefore, the composition according to one embodiment of the present invention can suppress the decrease in enzyme activity when the enzyme is stored in a dry state.

Enzymes contained in the reaction components include, for example, glucose oxidase (GOD), glucose dehydrogenase (GDH), glucose-6-phosphate dehydrogenase (G6P), diaphorase (DI), creatinine amidohydrolase (CNH), creatine amidinohydrolase (CRH), sarcosine oxidase (SAO), as well as peroxidase (POD), uricase (UAO), urease (URH), pyruvate oxidase (PYO), and hexokinase (HK). The type of enzyme can be determined appropriately depending on the type of component to be measured.

As an example, when the component to be measured is glucose (GLU), the enzyme serving as a reaction component contained in a composition according to one embodiment of the present invention preferably includes at least one glucose-specific enzyme selected from the group consisting of GOD, GDH, and G6P, and more preferably includes GDH. Here, the "glucose-specific enzyme" refers to an enzyme that specifically reacts with GLU as a reaction substrate. The enzyme preferably further includes diaphorase (DI).

Furthermore, for example, if the component to be measured is creatinine (CREA), the enzymes serving as reaction components preferably include creatinine amidohydrolase (CNH), creatine amidinohydrolase (CRH), sarcosine oxidase (SAO), and peroxidase (POD).

From the standpoint of reaction sensitivity, the composition according to one embodiment of the present invention preferably contains an enzyme so that it has a specific activity of 0.001 U/mg or more, and more preferably contains an enzyme so that it has a specific activity of 0.01 U/mg or more. Furthermore, although a high enzyme content in the composition according to one embodiment of the present invention is not a problem, from the standpoint of economy, it is preferable to contain an enzyme so that it has a specific activity of 1,000 U/mg or less, and more preferably contains an enzyme so that it has a specific activity of 100 U/mg or less.

(substrate)
The substrate may be a conventionally known substrate, and examples thereof include oxidized nicotinamide adenine dinucleotide (NAD), adenosine triphosphate (ATP), adenosine diphosphate (ADP), flavin adenine dinucleotide disodium n-hydrate (FAD), oxidized nicotinamide adenine dinucleotide phosphate (NADP), and thionicotinamide-adenine dinucleotide (Thio-NAD+).

The content of the substrate in a composition according to one embodiment of the present invention may be set appropriately depending on the object to be measured from the standpoint of reaction sensitivity, but is preferably 0.1% by weight or more, and more preferably 1% by weight or more, relative to 100% by weight of the composition. Furthermore, from the standpoint of storage stability, the content is preferably 90% by weight or less, and more preferably 80% by weight or less, relative to 100% by weight of the composition.

(dye)
As the dye, a conventionally known dye can be used, for example, a tetrazolium salt, a leuco dye, a Trinder's reagent, a pH indicator, a chelating color reagent, an indicator substance for enzyme reactions (GluCANA), etc. Among these, a leuco dye or a tetrazolium salt can be preferably used as the dye.

The tetrazolium salt can be a conventionally known substance, such as 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium monosodium salt (WST-8); 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium monosodium salt (WST-1); 2-(4-iodophenyl)-3-(2,4-dinitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium monosodium salt (WST-3); 2-benzothiazole-3-(4-carboxy-2-methoxyphenyl)-5-[4-(2-sulfoethylcarbamoyl)phenyl]-2H-tetrazolium (WST -4); 2,2'-dibenzothiazolyl-5,5'-bis[4-di(2-sulfoethyl)carbamoylphenyl]-3,3'-(3,3'-dimethoxy-4,4'-biphenylene)ditetrazolium disodium salt (WST-5); 2-(4-nitrophenyl)-5-phenyl-3-[4-(4-sulfophenylazo)-2-sulfophenyl]-2H-tetrazolium monosodium salt (WST-9); 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT); 3,3'-[3,3'-dimethoxy-(1,1'-biphenyl)-4,4'-diyl]-bis[2-(4-nitrophenyl)-5-phenyl-2H-tetrazolium chloride (NITR-TB); and the like.

Leuco dyes can be any conventionally known substance, such as triphenylmethane derivatives, phenothiazine derivatives, and diphenylamine derivatives. More specific examples include triphenylmethane derivatives such as 4,4'-benzylidenebis(N,N-dimethylaniline); phenothiazine derivatives such as 10-(carboxymethylaminocarbonyl)-3,7-bis(dimethylamino)phenothiazine salt (DA-67), 10-(methylaminocarbonyl)-3,7-bis(dimethylamino)phenothiazine, and 10-(N-methylcarbamoyl)-3-dimethylamino-7-hydroxy-10H-phenothiazine; diphenylamine derivatives such as 4,4'-bis(dimethylamino)diphenylamine and N-(carboxymethylaminocarbonyl)-4,4'-bis(dimethylamino)diphenylamine salt (DA-64); and 1-(ethylaminothiocarbonyl)-2-(3,5-dimethoxy-4-hydroxyphenyl)-4,5-bis(4-diethylaminophenyl)imidazole. Here, the salt is not particularly limited, but examples include sodium salts, potassium salts, calcium salts, etc.

The tetrazolium salt is reduced by an electron carrier in the presence of DI to produce a formazan dye, a color pigment. The electron carrier can be a conventionally known substance capable of reducing the tetrazolium salt to produce a formazan dye, such as reduced nicotinamide adenine dinucleotide (NADH) or reduced nicotinamide adenine dinucleotide phosphate (NADPH). As shown in the following formula (1), NADH is produced by reacting GDH with GLU in the presence of NAD.

For this reason, when the component to be measured is GLU, tetrazolium salts are preferably used as dyes from the standpoint of sensitivity.

Furthermore, the leuco dye is oxidized by the action of peroxidase _and hydrogen peroxide ( _H2O2 ) to produce the color dye methylene blue (MB). _H2O2 is produced during the reaction between _creatinine , the component to be measured, and an enzyme, which is a reactive component in the composition according to one embodiment of the present invention. Therefore, when the component to be measured is CREA, a leuco dye can be preferably used as the dye from the viewpoint of sensitivity.

The content of the dye in the composition according to one embodiment of the present invention must be adjusted appropriately depending on the substance to be measured, but is preferably 0.01% by weight or more, and more preferably 0.1% by weight or more, relative to 100% by weight of the composition. Furthermore, from the viewpoints of stability, the self-coloring of the dye, and the effect on the measurement value of the color of the dye before discoloration, the content is preferably 50% by weight or less, and more preferably 30% by weight or less, relative to 100% by weight of the composition.

<Other ingredients>
The composition according to one aspect of the present invention may contain, as necessary, components other than the above-mentioned components, as long as the effects of the present invention are not impaired. For example, the composition according to one aspect of the present invention preferably further contains at least one selected from the group consisting of a buffer salt and an additive.

(buffer salts)
The buffer salt may be a conventionally known substance that has the effect of buffering the pH of the reaction system, and examples thereof include 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES), 2-morpholinoethanesulfonic acid (MES), phosphate buffered saline (PBS), N-[Tris(hydroxymethyl)methyl]glycine (Tricine), N,N-Bis(2-hydroxyethyl)glycine (Bicine), and other so-called "good buffers." The buffer salt may be selected appropriately according to the pH.

The content of buffer salt in the composition according to one embodiment of the present invention is not particularly limited, but from the viewpoint of buffer capacity, it is preferably 0.01% by weight or more, and more preferably 0.1% by weight or more, relative to 100% by weight of the composition. Furthermore, there is no particular upper limit to the content of buffer salt in the composition according to one embodiment of the present invention.

(Additives)
Examples of additives include stabilizing components other than trehalose, excipients, preservatives, surfactants, synthetic polymers having surface activity, and the like.

Stabilizing components other than trehalose can be one or more compounds selected from the group consisting of sugars containing 2 to 4 monosaccharides, sugar alcohols, amino acids, and salts containing amino acids and carboxylic acids. Examples of compounds that can be suitably used are as follows:

Examples of sugars containing 2 to 4 monosaccharides include disaccharides such as sucrose (cane sugar), lactulose, lactose, maltose, cellobiose, kojibiose, nigerose, isomaltose, sophorose, laminaribiose, gentiobiose, turanose, maltulose, palatinose, gentiobiulose, mannobiose, melibiose, melibiulose, neolactose, galactosucrose, scillabiose, neohesperidose, rutinose, rutinulose, vicianose, xylobiose, and primeverose; trisaccharides such as nigerotriose, maltotriose, melezitose, maltotriulose, raffinose, and kestose; and tetrasaccharides such as nystose, nigerotetraose, and stachyose. Of these, sucrose, lactose, maltose, palatinose, maltotriose, and raffinose are preferred in terms of stabilizing effect and ease of availability. Sucrose and maltose are even more preferred in terms of their stabilizing effect.

Suitable sugar alcohols include glycerol, erythritol, threitol, arabinitol, xylitol, sorbitol, lactitol, mannitol, and maltitol.

In the composition according to one embodiment of the present invention, there are no particular limitations on the amino acids used as stabilizing components, but preferred amino acids include basic amino acids such as arginine, histidine, and lysine.

Inorganic salts of amino acids can also be suitably used. Examples include inorganic salts of acidic amino acids such as sodium aspartate, potassium aspartate, sodium glutamate, and potassium glutamate.

Salts containing amino acids and carboxylic acids can be used without particular restrictions, but a suitable combination is a salt containing a basic amino acid and a non-volatile carboxylic acid, as this prevents the carboxylic acid from evaporating and allows the effects of the stabilizing component to be maintained for a long time. More specific examples are as follows:

Basic amino acids include arginine, histidine, and lysine.

Carboxylic acids include acetic acid, lactic acid, butyric acid, octanoic acid, and other acids that have one carboxyl group per molecule; dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, phthalic acid, isophthalic acid, terephthalic acid, fumaric acid, malic acid, and tartaric acid, which have two carboxyl groups per molecule; and tricarboxylic acids such as citric acid, isocitric acid, and oxalosuccinic acid. Among these, dicarboxylic acids and tricarboxylic acids are more suitable because they can prevent decomposition of the salt due to volatilization of the carboxylic acid when forming a salt with an amino acid. Preferable carboxylic acids include malic acid, tartaric acid, and citric acid, taking into account their effectiveness as stabilizing components and ease of availability.

These stabilizing components other than trehalose may be used alone or in combination of two or more.

The content of stabilizing components other than trehalose in a composition according to one embodiment of the present invention is not particularly limited, but from the standpoint of stability, it is preferably 0.1% by weight or more, and more preferably 1% by weight or more, relative to 100% by weight of the composition. Furthermore, from the standpoint of storage stability, it is preferably 90% by weight or less, and more preferably 80% by weight or less, relative to 100% by weight of the composition.

The excipient used should preferably be a substance that does not interfere with the target reaction and that undergoes minimal deformation even at high temperatures when mixed with the stabilizing component. In other words, the following substances are included as excipients in the composition of one embodiment of the present invention: polysaccharides; cyclic sugars; proteins such as albumin; glucose; etc. The stabilizing component itself can also function as an excipient.

The excipient is composed of at least six or more monosaccharides, and includes at least one selected from the group consisting of polysaccharides (referred to as "polysaccharides of the present invention") containing 3 x n or more hydroxyl groups, where n is the number of monosaccharides (n is an integer), and polymers having an amino acid skeleton.

Any polysaccharide that contains a certain number of hydroxyl groups can be used as an excipient, as this increases its solubility in water. Examples of such polysaccharides include linear polysaccharides such as cellulose, chitin, starch, glycogen, agarose, carrageenan, dextran, and dextrin (k, 3xk); as well as cyclic polysaccharides such as cyclodextrins, including α-cyclodextrin and its methylated or hydroxypropylated derivatives, β-cyclodextrin and its methylated or hydroxypropylated derivatives, and γ-cyclodextrin and its methylated or hydroxypropylated derivatives.

Among these, polysaccharides containing at least six monosaccharides and containing 3 x n or more hydroxyl groups, where n is the number of monosaccharides (n is an integer), are preferred.

Specific examples of suitable polysaccharides that can be used as excipients include linear polysaccharides such as starch, glycogen, dextran, and dextrin, as well as cyclic polysaccharides such as cyclodextrins, including α-cyclodextrin and its methylated or hydroxypropylated derivatives, β-cyclodextrin and its methylated or hydroxypropylated derivatives, and γ-cyclodextrin and its methylated or hydroxypropylated derivatives. Even more preferred examples include dextran and cyclodextrins, which are easily soluble in water.

A polymer with an amino acid backbone that can be used as an excipient is one in which multiple single amino acids are linked in a linear fashion. Specific examples include polylysine, which is made up of L-lysine bonds, and poly-L-arginine and its hydrochloride, which are made up of arginine bonds.

These excipients may be used alone or in combination of two or more. Furthermore, enzyme stability can be improved by combining the excipient with an inorganic salt such as sodium chloride or potassium chloride.

The content of excipients in a composition according to one embodiment of the present invention is not particularly limited, but from the viewpoint of the effect of the excipients, it is preferably 0.01% by weight or more, and more preferably 0.1% by weight or more, relative to 100% by weight of the composition. Furthermore, from the viewpoint of the solubility of the excipients, it is preferably 90% by weight or less, and more preferably 80% by weight or less, relative to 100% by weight of the composition.

Substances that can be suitably used as surfactants include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants, as long as they are necessary for the reaction or do not affect the reaction. Nonionic surfactants can be used without particular restrictions, as long as they can be mixed with the stabilizing components. Examples of commonly available surfactants include: polyoxyethylene lauryl ether sugar polyoxyethylene fatty acid ethers; sorbitan fatty acid esters such as sorbitan monolaurate and sorbitan monooleate; 3-[(3-Cholamidopropyl)dimethylammonium]propanesulfonate (CHAPS); Triton-X; SDS; and others. Because surfactants can inhibit enzymatic reactions, they are generally added in smaller amounts than polysaccharides.

One type of surfactant may be used alone, or two or more types may be used in combination. The surfactant content in a composition according to one embodiment of the present invention is not particularly limited, but from the perspective of obtaining the effects of the surfactant, it is preferably 0.01% by weight or more, and more preferably 0.05% by weight or more, relative to 100% by weight of the composition. Furthermore, taking into account the effect on the enzyme reaction, it is preferably 10% by weight or less, and more preferably 5% by weight or less, relative to 100% by weight of the composition.

Substances that can be suitably used as preservatives include sodium azide and Proclin, as long as they are necessary for the reaction or do not affect the reaction.

A single type of preservative may be used, or two or more types may be used in combination. The content of the preservative in the composition according to one embodiment of the present invention is not particularly limited, but from the perspective of obtaining the effects of the preservative, it is preferably 0.01% by weight or more, and more preferably 0.05% by weight or more, relative to 100% by weight of the composition. Furthermore, considering that the preservative itself can be toxic at high concentrations, it is preferably 1% by weight or less, and more preferably 0.1% by weight or less, relative to 100% by weight of the composition.

(Examples of combinations of enzymes, substrates and dyes)
The combination of the enzyme and the optional substrate and dye contained in the composition according to one aspect of the present invention may be determined appropriately depending on the type of component to be measured and the reaction type to be used.

An example will be described in which the component to be measured is GLU. The composition according to embodiment 1 of the present invention contains GOD and POD as enzymes, and a leuco dye and Trinder's reagent as dyes. The composition according to embodiment 1 of the present invention does not contain a substrate. The composition according to embodiment 1 of the present invention can be preferably used to form a GLU reagent for measuring GLU in a serum sample using a conventionally known colorimetric method.

The composition according to embodiment 2 of the present invention contains GDH and DI as reaction components, NAD as a substrate, and WST-4 as a dye. The composition according to embodiment 2 of the present invention can be preferably used to construct a GLU reagent using dry chemistry technology to measure GLU in a serum sample using a conventionally known colorimetric method.

The composition according to embodiment 3 of the present invention contains G6P and HK as reaction components, and ATP and NAD as substrates. The composition according to embodiment 3 of the present invention does not contain a dye, as it is sufficient to measure the wavelength of NADH. The composition according to embodiment 3 of the present invention can be preferably used to form a GLU reagent using dry chemistry technology to measure GLU in a serum sample using a conventionally known colorimetric method.

Next, an example will be described in which the component to be measured is CREA. The composition according to embodiment 4 of the present invention contains CNH, CRH, SAO, and POD as reactive components, and DA-67 as a dye. The composition according to embodiment 4 of the present invention can be preferably used to form a CREA reagent using dry chemistry technology to measure CREA in a serum sample using a conventionally known colorimetric method.

<Form and properties of the composition>
The composition according to one embodiment of the present invention is preferably solid and in a glassy state. Here, the term "glassy state" refers to a state in which the composition is stored at a temperature above the boiling point and below the glass transition temperature (Tg). Since the composition according to one embodiment of the present invention contains trehalose, which has a high glass transition temperature, it is in a glassy state at room temperature (15°C to 40°C).

Enzymes, substrates, and dyes are generally unstable at room temperature, but the composition according to one embodiment of the present invention is solid and in a glassy state, allowing it to be stored at room temperature or above. More specifically, the storage temperature for the composition according to one embodiment of the present invention can be 1°C to 60°C, and more preferably 1°C to 40°C. The composition according to one embodiment of the present invention may also be stored at 2°C to 8°C, the storage temperature for typical dry reagents.

<Uses of the composition>
The composition according to one embodiment of the present invention can be used for various dry reagent applications utilizing dry chemistry technology by appropriately selecting the types of reaction components and optional components, such as substrate and dye, depending on the purpose. The composition according to one embodiment of the present invention can be, for example, a GLU reagent composition, a CREA reagent composition, an AST reagent composition, an ALT reagent composition, or a BUN reagent composition.

Furthermore, the composition according to one embodiment of the present invention has improved storage stability of the reaction components while retaining bound water, making it possible to apply it to slide-reagent-type dry chemistry techniques. Therefore, the composition according to one embodiment of the present invention can be used as a slide-reagent composition.

Furthermore, because the composition according to one embodiment of the present invention is solid and in a glassy state, it can be stored at room temperature. Therefore, the composition according to one embodiment of the present invention can be used as a dry reagent composition for storage at room temperature.

<Method of producing the composition>
An example of a method for producing a composition according to one embodiment of the present invention will be described below. The composition according to one embodiment of the present invention can be produced by a production method including the following steps (i) and (ii):
(i) mixing the components of the composition according to one aspect of the present invention in the same solvent to prepare a homogeneous solution;
(ii) A step of drying the solution obtained in the step (i).

This production method allows the reaction components and trehalose to be thoroughly mixed. As a result, trehalose can be present around or inside the molecules of the reaction components. As mentioned above, trehalose can substitute for the functions of water, such as hydrogen bonding and providing a hydrophilic environment. Therefore, the presence of trehalose around or inside the reaction components makes it less likely that the structure of the reaction components will be recombined, and reduces the decrease in activity of the reaction components.

Each step will be explained below.
(Step (i))
The main components of the composition according to one embodiment of the present invention, including the reactive components, are generally used in aqueous solutions. Therefore, the solvent is generally water. The method for mixing the components of the composition according to one embodiment of the present invention in step (i) is not particularly limited, and known methods can be used. Examples include vortex mixing and ultrasonic dispersion.

(Step (ii))
The method for drying the solution obtained in step (i) is not particularly limited, and known methods can be used. Examples include air drying, hot air drying, spray hot air drying, and freeze drying. As an example, when the reaction component contains an enzyme, freeze drying and air drying are preferably used as methods for drying the solution obtained in step (i). As another example, when a composition according to one aspect of the present invention is applied to a slide-reagent-type dry chemistry technique, it is preferable that bound water remains in the dried product, and therefore air drying is preferably used as a method for drying the solution obtained in step (i).

The method for naturally drying a composition according to one embodiment of the present invention is not particularly limited, and any known method can be used. For example, a composition according to one embodiment of the present invention can be placed in a desiccator at room temperature (15°C to 40°C) together with a drying protection agent, and dried overnight in a low-humidity environment. Here, the "low-humidity environment" refers to an environment at room temperature with a relative humidity of 30% RH or less.

Drying protection agents include conventionally known substances used to dry and protect objects to be dried. Examples of such substances include calcium chloride and synthetic zeolite (molecular sieves). Here, "protection" by a drying protection agent means protecting the object from absorbing moisture. Therefore, it is preferable for the drying protection agent to be a desiccant that can adsorb moisture down to low humidity ranges (around 10% RH).

[2. Dry Reagents]
A dry reagent according to one aspect of the present invention includes the composition according to one aspect of the present invention, a drying protection agent that dries and protects the composition, and a packaging material that packages the composition and the drying protection agent, thereby making it possible to provide a dry reagent that contains a specific amount of moisture but has excellent storage stability.

(composition)
The composition according to one embodiment of the present invention has been described above, and therefore will not be described again here. In the dry reagent according to one embodiment of the present invention, the composition according to one embodiment of the present invention is provided in a dried state on a support. Examples of the support include optically transparent materials such as polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), and styrene-acrylonitrile resin (ABS resin).

(Drying protection agent)
The drying protection agent has been explained above in the section "Method for producing the composition," and therefore the explanation will not be repeated here.

(packaging material)
Examples of packaging materials include aluminum-deposited resin films and film-like desiccants for packaging.

The shape and size of the packaging material may be such that it is capable of packaging the composition and drying protectant according to one embodiment of the present invention.

From the standpoint of preventing moisture absorption, it is preferable to hermetically package the composition according to one embodiment of the present invention and the desiccant protectant in a packaging material. For example, the composition according to one embodiment of the present invention and the desiccant protectant can be hermetically packaged in a packaging material by heat-sealing the opening of an aluminum pouch using heat compression.

In terms of temperature fluctuations, it is preferable that the gas pressure inside the packaging material containing the composition according to one embodiment of the present invention and the drying protection agent be approximately atmospheric pressure. In this specification, "approximately atmospheric pressure" means a pressure in the range of 1,000 hPa to 1,100 hPa, and preferably a pressure in the range of 1,010 hPa to 1,020 hPa.

From the standpoint of preventing moisture absorption, it is preferable that the relative humidity inside the packaging material containing the composition according to one embodiment of the present invention and the drying protection agent be 30% RH or less at 20°C, and that the moisture content in the gas at 40°C be 30% RH or less.

The relative humidity at 20°C is preferably 30% RH or less, and even more preferably 10% RH or less. From the perspective of preventing moisture absorption, the lower the relative humidity at 20°C, the better, and there is no particular lower limit, but from the perspective of the performance of the drying protection agent, it may be 1.0% RH or more.

The moisture content of the gas inside the packaging material at 40°C is preferably 30% RH or less, and even more preferably 10% RH or less. From the perspective of preventing moisture absorption, the lower the moisture content of the gas inside the packaging material at 40°C, the better, and although there is no particular lower limit, from the perspective of the performance of the drying protection agent, it may be 1.0% RH or more.

The relative humidity inside the packaging material and the amount of moisture in the gas refer to values measured by a method in which a temperature and humidity logger is included inside and the internal humidity is recorded.

The dry reagent according to one embodiment of the present invention has the advantage that it can be dissolved in a blood sample when needed, allowing for immediate qualitative and quantitative measurements. This is explained in detail below.

In the field of clinical testing, there is a series of tests (measurements) known as biochemical tests. Biochemical tests quantify inorganic substances, low-molecular-weight organic compounds, proteins, enzymes, and other substances contained in bodily fluids such as blood.

These tests often involve mixing the test reagent with blood or other fluid (serum, plasma, cerebrospinal fluid) in an aqueous solution, allowing the components of the test reagent to react with those of the blood, etc., and measuring the change in absorbance due to a color reaction or other such reaction.

Enzymes are also often used as components of test reagents. For example, a reagent for measuring glucose in serum quantifies the amount of NADPH produced by the following reaction using the change in absorbance at 340 nm, the absorption wavelength specific to NADPH.

<Enzyme reaction by hexokinase>
Glucose + ATP → glucose-6-phosphate + ADP
(The reaction proceeds in the presence of Mg ions)
<Enzyme reaction by glucose-6-phosphate dehydrogenase>
Glucose-6-phosphate + ADP → D-gluconolactone-6-phosphate + NADPH + H ⁺
This reaction can be utilized to construct a dry reagent for measuring glucose in a serum sample. The composition according to one embodiment of the present invention is prepared so as to contain the necessary amounts of ATP, hexokinase, a pH buffer, and a Mg salt used in the reaction, and the composition is placed in a measurement cell in a dry state, thereby constructing a dry reagent according to one embodiment of the present invention.

The composition according to one embodiment of the present invention contains a specific amount of trehalose, which gives it excellent storage stability. Therefore, a dry reagent containing such a composition according to one embodiment of the present invention has excellent long-term storage stability, can be stored at room temperature or above, and can be dissolved in a blood sample when needed to perform immediate qualitative and quantitative measurements.

Conventional dry reagents for measuring biological samples, which require refrigerated or frozen storage, are heated to 37°C, the optimum reaction temperature for the enzymes contained in the dry reagent, just before measurement before being used. For this reason, conventional dry reagents for measuring biological samples require several minutes to several tens of minutes before measurement can begin, and there is a desire to shorten this time. Furthermore, conventional dry reagents for measuring biological samples can crack when heated to 37°C, causing the dry reagent to fall out of the container, resulting in the inability to perform the required measurement.

In contrast, the dry reagent according to one embodiment of the present invention can be stored at room temperature or above, and therefore does not require a step of heating the dry reagent. As a result, the dry reagent according to one embodiment of the present invention can significantly reduce the time from when it is removed from storage until it is used for measurement, and is less likely to suffer from defects such as cracks that prevent measurement from being performed. Therefore, the dry reagent according to one embodiment of the present invention has improved usability compared to conventional dry reagents for measuring biological samples.

The use of the dry reagent according to one embodiment of the present invention is not particularly limited, and it can be used, for example, for clinical testing and research in the field of biochemistry.

[3. Analysis method]
The present invention also includes a method for analyzing a biological sample using a dry reagent according to an embodiment of the present invention. Analyzing a biological sample using a dry reagent according to an embodiment of the present invention has the advantages of significantly shortening the time from removal from storage to measurement, and of being less susceptible to defects such as cracks that would prevent measurement.

4. Method for storing the composition
A method for preserving a composition according to one embodiment of the present invention is also included in the scope of the present invention. That is, the method for preserving a composition according to one embodiment of the present invention is as follows:
A method for preserving a composition comprising trehalose, a reactive component that reacts with a target component to be measured contained in a biological sample, and water, wherein the composition contains 0.2% by weight or more and 90% by weight or less of trehalose and 1% by weight or more and 30% by weight or less of water relative to the total weight of the composition, and the weight of the water is 5 times or less the weight of the trehalose.

Furthermore, a method for preserving a composition according to another embodiment of the present invention is as follows:
A method for storing a composition according to one aspect of the present invention as a dry reagent, comprising: a composition according to one aspect of the present invention; a dry protection agent that dries and protects the composition; and a packaging material that packages the composition and the dry protection agent.

In the method for preserving a composition according to one embodiment of the present invention, it is preferable to use a composition that is solid and in a glassy state.

〔summary〕
A composition according to a first aspect of the present invention comprises a reactive component that reacts with a target component to be measured contained in a biological sample, trehalose, and water, and the composition contains 0.2% by weight or more and 90% by weight or less of the trehalose and 1% by weight or more and 30% by weight or less of the water, relative to the total weight of the composition, and the weight of the water is 5 times or less the weight of the trehalose.

The composition according to aspect 2 of the present invention is preferably solid and in a glassy state in accordance with aspect 1 above.

In the composition according to aspect 3 of the present invention, in the above-mentioned aspect 1 or 2, it is preferable that the water content is 3% by weight or more and 10% by weight or less.

The composition according to aspect 4 of the present invention, in any one of aspects 1 to 3 above, preferably contains 1.0% by weight or more and 80% by weight or less of the trehalose.

In the composition according to aspect 5 of the present invention, in any one of aspects 1 to 4 above, the reaction component may include an enzyme.

The composition according to aspect 6 of the present invention, in any one of aspects 1 to 5 above, may further contain at least one selected from the group consisting of substrates, dyes, buffer salts, and additives.

A composition according to aspect 7 of the present invention is the same as that according to aspect 6 above, wherein the dye is a leuco dye or a tetrazolium salt.

A dry reagent according to aspect 8 of the present invention comprises the composition described in any one of aspects 1 to 7 above, a dry protection agent that dries and protects the composition, and a packaging material that packages the composition and the dry protection agent.

A dry reagent according to Aspect 9 of the present invention is the same as Aspect 8 above, except that the pressure of the gas inside the packaging material is approximately atmospheric pressure, the relative humidity inside the packaging material is 30% RH or less at 20°C, and the moisture content of the gas at 40°C is preferably 30% RH or less.

A method for preserving a composition according to aspect 10 of the present invention is a method for preserving a composition comprising a reactive component that reacts with a target component to be measured contained in a biological sample, trehalose, and water, wherein the trehalose is contained in an amount of 0.2% by weight or more and 90% by weight or less, and the water is contained in an amount of 1% by weight or more and 30% by weight or less, relative to the total weight of the composition, and the weight of the water is 5 times or less the weight of the trehalose.

In the method for preserving a composition according to aspect 11 of the present invention, it is preferable to use a composition in the above-mentioned aspect 10, in which the composition is in a solid and glassy state.

A method for storing a composition according to aspect 12 of the present invention is a method for storing the composition as a dry reagent comprising the composition according to any one of aspects 1 to 7 above, a dry protectant that dries and protects the composition, and a packaging material that packages the composition and the dry protectant.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in each embodiment are also included in the technical scope of the present invention.

The present invention will be explained in more detail below using examples. The present invention is not limited to these examples.

<1. Confirming moisture content using IR>
[Experimental Procedure]
(1) Using calcium chloride desiccant, the relative humidity around the measurement unit (single reflection attenuated total reflection (ATR) method: diamond crystal) of an IR (PerkinElmer Japan, Model No. Spectrum 100A) was adjusted to 10% RH or less.
(2) 0.5 μL of a sample to be measured containing 1 wt % trehalose and 0.5 wt % CHAPS was dropped onto the IR measurement section and dried.
(3) The IR spectrum was measured at the elapsed time to quantify the amount of water, under the measurement conditions of a measurement range of 500 to 4000 cm ⁻¹ , a resolution of 4 cm ⁻¹ , and four accumulations.
The amount of residual water was calculated from the area of the peak at 1640 cm ⁻¹ obtained. The calculation of the amount of residual water was performed using the amount of water prepared in advance from a standard sample with a known amount of water and a calibration curve of the area of the peak at 1640 cm ⁻¹ .

[result]
After 24 hours, the residual moisture content reached a plateau, and it was found that approximately 3.0% by weight remained.

<2. Measurement of Glass Transition Temperature>
(Raw materials for test reagents)
Trehalose (α,α-trehalose; manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
- Mannitol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
・CHAPS (manufactured by Dojindo Chemical Research Institute Co., Ltd.)

[Experimental Procedure]
(1) Test reagents for the Examples and Comparative Examples were prepared according to the blending ratios shown in Table 2.
(2) It was dried overnight in a desiccator.
(3) Differential scanning calorimetry (DSC) was carried out under the following conditions.
Use an aluminum sample pan. Sample amount: 1 to 10 mg.
Heating rate: 10°C/min, temperature range: 30°C to 120°C.

[result]
The glass transition temperatures of the test reagents in the examples were as follows:
Example 1: 60°C, Example 2: 50°C
These results indicated that the glass transition temperatures of the test reagents containing trehalose were above room temperature (40°C) and that these test reagents were in a glassy state at room temperature.

In contrast, the glass transition temperatures of the test reagents in Comparative Examples 1 and 2 were each below 30°C, suggesting that their glass transition temperatures were below room temperature.

<3. Evaluation of storage stability of GLU reagent>
(Raw material for R1 reagent)
・GDH (manufactured by Toyobo Co., Ltd.)
・DI (manufactured by Toyobo Co., Ltd.)
pH 7.0 HEPES buffer (manufactured by Dojindo Laboratories, Inc.)
Trehalose (α,α-trehalose; manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
- Mannitol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

(Raw material for R2 reagent)
β-NAD (manufactured by Oriental Yeast Co., Ltd.)
・WST-4 (manufactured by Dojindo Laboratories Co., Ltd.)
・pH7.0 HEPES (manufactured by Dojindo Laboratories Co., Ltd.)
Trehalose (α,α-trehalose; manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
- Mannitol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

(Measurement sample)
The following measurement samples were used.
Blank sample (150 mM PBS buffer)
- Low concentration adjusted sample (GLU: approximately 80 mg/dL)
High concentration adjusted sample (GLU: approximately 350 mg/dL)

[Experimental Procedure]
(1) A GLU reagent for measuring GLU in serum samples was prepared using the following reaction:
More specifically, reagents R1 and R2 were prepared in the blending ratios shown in Tables 3 and 4, respectively.
(2) 100 μL each of the R1 reagent and the R2 reagent was dropped onto a well plate (manufactured by AS ONE Corporation, model number 1-6776-01).
(3) The reagent container from (2) above was placed in a desiccator together with a calcium chloride desiccant, and dried overnight in a low humidity environment (relative humidity 10% RH).
(4) The reagent container from (3) above was placed in an aluminum pouch together with a calcium chloride desiccant, and the pouch was sealed to prepare a dry reagent.
(5) The dry reagent of (4) was stored at 60°C for one month.
(6) After storage, the dried reagents were redissolved in 100 μL of ultrapure water (MilliQ (registered trademark) water), with the R1 reagent and the R2 reagent being redissolved.
(7) 100 μL of the R1 reagent and 100 μL of the R2 reagent prepared in (6) above were mixed with 4 μL of each measurement sample.
(8) Using a spectrophotometer (TECAN, Infinite PRO), the absorbance at 630 nm was measured at the end of the reaction.
Criteria: Absorbance fluctuation is within 10%

[result]
The results are shown in Table 5.

In Table 5, the absorbance values to the left of the arrows are the absorbance values measured after drying and before storage at 60°C, and the values to the right of the arrows are the absorbance values measured using the test reagents after storage at 60°C for one month.

Regarding storage stability, if the rate of change in absorbance was ±20% or less, it was evaluated as there was no deterioration of the reagent, and if the rate of change exceeded ±20%, it was evaluated as there was deterioration of the reagent.

A comparison of Example 3 and Comparative Example 3 showed that the reagent composition of Example 3, which contains trehalose, was able to improve the stability of the GLU reagent compared to the reagent composition of Comparative Example 3, which contains mannitol. These results demonstrate that the GLU reagent comprising the reagent composition of Example 3, which contains trehalose, has excellent storage stability despite containing a specific amount of moisture. Furthermore, the rate of change in absorbance of the blank sample in Example 3 was 25.0%, but this corresponds to an increase of approximately 5 mg/dL in concentration, which does not significantly affect the measurement results and was therefore determined to be no degradation.

<4. Evaluation of storage stability of CREA reagent>
(Raw material for R1 reagent)
・CNH (manufactured by Toyobo Co., Ltd.)
・CRH (manufactured by Toyobo Co., Ltd.)
・SAO (manufactured by Toyobo Co., Ltd.)
・POD (manufactured by Toyobo Co., Ltd.)
pH 7.0 HEPES buffer (manufactured by Dojindo Laboratories, Inc.)
Trehalose (α,α-trehalose; manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
- Mannitol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

(Raw material for R2 reagent)
DA-67 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
・pH7.0 HEPES (manufactured by Dojindo Laboratories Co., Ltd.)
Trehalose (α,α-trehalose; manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
- Mannitol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

(Measurement sample)
The following measurement samples were used.
Blank sample (150 mM PBS buffer)
- Low concentration adjusted sample (CREA: approximately 1.0 mg/dL)
High concentration adjusted sample (CREA: approximately 6.5 mg/dL)

[Experimental Procedure]
(1) A CREA reagent for measuring CREA in serum samples was prepared using the following reaction.
More specifically, reagents R1 and R2 were prepared in the blending ratios shown in Tables 6 and 7, respectively.
(2) 100 μL each of the R1 reagent and the R2 reagent was dropped onto a well plate (manufactured by AS ONE Corporation, model number 1-6776-01).
(3) The reagent container from (2) above was placed in a desiccator together with a calcium chloride desiccant, and dried overnight in a low humidity environment (relative humidity 10% RH).
(4) The reagent container from (3) above was placed in an aluminum pouch together with a calcium chloride desiccant, and the pouch was sealed to prepare a dry reagent.
(5) The dry reagent of (4) was stored at 60°C for one month.
(6) After storage, the dried reagents were redissolved in 100 μL of ultrapure water (MilliQ (registered trademark) water), with the R1 reagent and the R2 reagent being redissolved.
(7) 100 μL of the R1 reagent and 100 μL of the R2 reagent prepared in (6) above were mixed with 4 μL of each measurement sample.
(8) Using a spectrophotometer (TECAN, Infinite PRO), the absorbance at 630 nm was measured at the end of the reaction.
Criteria: Absorbance fluctuation is within 10%

[result]
The results are shown in Table 8.

In Table 8, the absorbance values to the left of the arrows are the absorbance values measured after drying and before storage at 60°C, and the values to the right of the arrows are the absorbance values measured using the test reagents after one month of storage at 60°C.

Regarding storage stability, if the rate of change in absorbance was ±20% or less, it was evaluated as there was no deterioration of the reagent, and if the rate of change exceeded ±20%, it was evaluated as there was deterioration of the reagent.

A comparison of Example 4 and Comparative Example 4 showed that the reagent composition of Example 4, which contains trehalose, was able to improve the stability of the CREA reagent compared to the reagent composition of Comparative Example 4, which contains mannitol. These results demonstrate that the CREA reagent comprising the reagent composition of Example 4, which contains trehalose, has excellent storage stability despite containing a specific amount of moisture.

This invention can be used for test reagents that utilize dry chemistry technology.

Claims (12)

a reactive component that reacts with a target component to be measured contained in a biological sample;
Trehalose and
Moisture and
Contains
based on the total weight of the composition,
The trehalose is 0.2% by weight or more and 90% by weight or less, and
The water content is 1% by weight or more and 30% by weight or less,
The weight of the water is 5 times or less the weight of the trehalose.
composition. It is both solid and glassy.
The composition of claim 1. The moisture content is 3% by weight or more and 10% by weight or less.
The composition according to claim 1 or 2. The trehalose is contained in an amount of 1.0% by weight or more and 80% by weight or less.
The composition according to claim 1 or 2. The reaction components include an enzyme.
The composition according to claim 1 or 2. Further containing at least one selected from the group consisting of substrates, dyes, buffer salts and additives;
The composition according to claim 1 or 2. The dye is a leuco dye or a tetrazolium salt.
The composition of claim 6. The composition according to claim 1 or 2,
a drying protectant that dries and protects the composition;
a packaging material that packages the composition and the dry protectant;
Equipped with
Dry reagents. The pressure of the gas inside the packaging material is approximately atmospheric pressure,
The inside of the packaging material has a relative humidity of 30% RH or less at 20°C, and the moisture content of the gas at 40°C is 30% RH or less.
The dry reagent according to claim 8. a reactive component that reacts with a target component to be measured contained in a biological sample;
Trehalose and
and a composition containing water.
based on the total weight of the composition
The trehalose is 0.2% by weight or more and 90% by weight or less, and
The water content is 1% by weight or more and 30% by weight or less,
A method for preserving the composition by making the weight of the water 5 times or less the weight of the trehalose. The method for preserving a composition according to claim 10, characterized in that the composition is solid and in a glassy state. The composition according to claim 1 or 2,
a drying protectant that dries and protects the composition;
a packaging material that packages the composition and the dry protectant;
A method for storing the composition as a dry reagent comprising: