JPH07270417A - Reagent for immunoassay and production thereof - Google Patents

Abstract

PURPOSE:To produce a highly sensitive reagent having excellent preservability and upon which natural coagulation or nonspecific coagulation does not occur by introducing a water-soluble polymer into and fixing it in a water-insoluble carrier, locally heightening the hydrophobic property of the carrier, increasing the adsorption quantity of an antibody or an antigen, and providing the carrier with hydrophilic property. CONSTITUTION:The reagent is produced by carrying an antibody or an antigen on a water-insoluble carrier and then adding an aqueous solution containing a water-soluble polymer having saccharose as a side chain in concentration range 0.01-4 pts. by wt. per 1 pt. by wt. of the carrier to an aqueous solution containing the antibody or the antigen. Latex particles are a desirable example for the water-insoluble carrier. The water-soluble polymer having saccharose is an ampholytic substance having a hydrophilic group and a hydrophobic group in one molecule and is made to have 20000-750000 molecular weight, preferably 350000-500000 molecular weight. Glycoside polymer e.g. homopolymer of glcosylethyl methacrylate is a desirable example for the polymer compound having saccharose as a side chain. The substance for the antibody or the antigen is protein, lipide, peptide, or their compounded bodies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an immunoassay reagent utilizing an antigen-antibody reaction, and more particularly to an immunoassay reagent having high sensitivity and less nonspecific reaction, and a method for producing the same.

[0002]

2. Description of the Related Art Antigen-antibody reaction is used as a method for detecting or quantifying a specific substance from a biological component. Since the antigen-antibody reaction has high specificity and high detection sensitivity, it is currently widely used as an important means for clinical tests. As a measurement method utilizing the antigen-antibody reaction, a method of performing the antigen-antibody reaction in an aqueous solution includes an enzyme immunoassay (EI
A), radioimmunoassay (RIA), immunoturbidimetric assay (TI)
A) and the like are known.

In particular, when latex particles or a plastic plate is used as the water-insoluble carrier, the antibody against the substance to be measured which is the antigen or the antibody or the antigen is efficiently and stably immobilized on the water-insoluble carrier as described above. This is an important technique for producing a highly sensitive and highly stable diagnostic drug.

As a method of immobilizing an antigen or an antibody on an insoluble carrier, there are methods such as adsorption or covalent bond, but generally, adsorption is easy and it is widely used because it does not impair the antigen activity or the antibody activity. ing. In addition to increasing the amount of the antigen or antibody used, the following methods have been considered as means for increasing the efficiency of adsorption of the antigen or antibody on the insoluble carrier.

(1) Using latex particles having a large particle size,
The contact area of the antigen or antibody with the carrier is increased (JP-A-5-297002).

(2) A carrier having a porous surface or a high roughness is used to increase the contact area of an antigen or an antibody (Japanese Patent Publication No. 3-22944, JP-A-4-174360).

[0007] In addition, since the hydrophobic interaction between the adsorbed antigen or antibody and the water-insoluble carrier plays a large role in physical adsorption, use of polystyrene latex particles having high surface hydrophobicity. Is also effective. Polystyrene latex-based latex particles are
Being a synthetic substance, it has better storage stability than other carriers, strongly adsorbs proteins such as antigens and antibodies and physiologically active substances such as lipids, and retains the properties of the bound antigens and antibodies unchanged. Since it is also excellent in that it can be used, it is used in many immunoreaction reagents, and is particularly often used as a carrier for agglutination reagents.

However, in the polystyrene latex synthetic latex, there is a tendency that the latex particles spontaneously aggregate during storage, or so-called non-specific aggregation occurs due to reaction between substances other than the target substance. In order to prevent this problem, conventionally, immunologically inactive albumins such as bovine serum albumin and equine serum albumin were added to the sensitized latex particle suspension to remove the hydrophobic surface of the latex particles. A latex reagent for immunological reaction was proposed in which natural aggregation of latex particles was prevented and nonspecific aggregation due to interfering substances was prevented by covering and keeping the surface charge negative (JP-A-58-144748).
Kohei 3-94161).

[0009]

However, the hydrophobicity of the surface is high, and the above-mentioned JP-A-5-297002 and JP-B-3-
As in the particles of No. 22944 and JP-A-4-174360, if the adsorption surface area is large, even proteins other than the target antigen or antibody will be nonspecifically adsorbed, followed by nonspecific reaction and nonspecific aggregation. Could also cause

In addition, in the case of a polystyrene latex-based synthetic latex, it was impossible to prevent spontaneous aggregation or non-specific aggregation of the sensitized carrier even after long-term storage even by adding the above-mentioned inert albumin. . In addition, since the concentration of albumin used is considerably high, the negative charge on the surface of the particles becomes too large, and the particles are stabilized, sometimes suppressing the originally necessary antigen-antibody reaction.

In view of the above points, an object of the present invention is to provide an immunoassay reagent which has high sensitivity and can be stored for a long time without the risk of spontaneous aggregation or non-specific aggregation.

[0012]

Means for Solving the Problems As a result of intensive studies aimed at achieving the above-mentioned object, the present inventor has found that a specific water-soluble polymer is immobilized on the surface of a water-insoluble carrier, thereby providing high sensitivity and non-sensitivity. The inventors have found that an immunoassay reagent with less specific reaction can be obtained, and completed the present invention.

That is, according to the present invention, there is provided an immunoassay reagent comprising a water-insoluble carrier carrying an antibody or an antigen, to which a water-soluble polymer having a saccharide in a side chain is introduced.

The immunoassay reagent according to the present invention comprises an antibody or an antigen supported on a water-insoluble carrier, and an aqueous liquid containing the carrier and the antibody or the antigen. It is produced by adding an aqueous liquid containing 0.01 to 4 parts by weight per part.

The immunoassay reagent according to the present invention also has a water-soluble high-solubility having a saccharide in a side chain in an aqueous solution containing the carrier before or simultaneously with the loading of the antibody or antigen on the water-insoluble carrier. 0.005 molecules per 1 part by weight of carrier
It is produced by adding an aqueous liquid containing a concentration of about 0.15 parts by weight.

In a preferred embodiment of the present invention, the immunoassay reagent is a water-insoluble carrier used in an immunodiagnostic agent, which carries an antigen or an antibody corresponding to the antibody to be measured or an antigen.

A preferred example of a water-insoluble carrier is latex particles.

The water-insoluble carrier applicable to the present invention may be any kind of latex particles obtained by synthesis, gelatin particles or the like, and may be a plastic microtiter plate or a test tube. Regarding the sensitization of the carrier surface, not only the physical adsorption method but also the solid surface having a functional group can be efficiently sensitized by the known chemical bonding method or covalent bonding method. it can. In addition, animal red blood cells, kaolin, carbon powder and the like can be applied to the present invention.

The water-soluble polymer having a sugar chain used in the present invention is an amphipathic substance having both a hydrophilic group and a hydrophobic group in the same molecule, and has a molecular weight of 20,000 to 750,000, preferably 150,000. ˜600,000, most preferably 250,000 to 500,000. As such a water-soluble polymer, for example,
Examples include homopolymers of glucosylethyl methacrylate and galactosylethyl methacrylate (International Publication Number: WO90 / 04598) synthesized by a known method, and synthetic polymers such as polyethylene glycol and animal serum albumin are proteolytic enzymes. ,acid,
It is also possible to use a product obtained by binding a saccharide to a decomposition product hydrolyzed by other appropriate means by an appropriate means and purifying by a suitable means.

A preferred example of the water-soluble polymer compound having a saccharide in the side chain is a glycoside polymer such as a homopolymer of glycosyl ethyl methacrylate.

The water-soluble polymer having a sugar chain has a molecular weight of 7
If it is larger than 50,000, the problem of non-specific aggregation of the latex reagent during long-term storage explained in the prior art is not solved, and if it is smaller than 20,000, the effect is sufficient for coating the latex particle surface and imparting hydrophilicity. You may not get it.

After carrying the antibody or antigen on the water-insoluble carrier, the reagent for immunoassay according to the present invention is produced by adding the aqueous liquid containing the water-soluble polymer to the aqueous liquid containing the carrier and the antibody or antigen. In the method described above, a water-soluble polymer is added to an aqueous liquid containing a water-insoluble carrier such as sensitized latex particles at an arbitrary concentration and containing an antibody or an antigen supported on the carrier in an amount of 0.01 to 4 per 1 part by weight of the carrier. Parts by weight, preferably 0.05 to 3.0 parts by weight, most preferably 0.1 to 3.0 parts by weight.
An aqueous liquor containing a concentration of 2.0 parts by weight is added.

If this concentration is less than 0.01 parts by weight,
The stability of the latex reagent due to the coating on the surface is not sufficient, and if it is more than 4.0 parts by weight, the dispersibility is too high and the measurement sensitivity becomes low. Therefore, the concentration of the water-soluble polymer is 0. It is from 01 to 4.0 parts by weight.

The immunoassay reagent according to the present invention is prepared by adding an aqueous solution containing a water-soluble polymer to an aqueous solution containing the carrier before or simultaneously with the loading of the antibody or antigen on the water-insoluble carrier. In the method described above, a water-insoluble carrier such as sensitized latex particles is suspended in an aqueous liquid at an arbitrary concentration, and the water-soluble polymer is added to the carrier 1 in the aqueous liquid containing the carrier.
0.005 to 0.15 part by weight, preferably 0.008 to 0.10 part by weight, and most preferably 0.01
Add an aqueous liquid containing at a concentration of ~ 0.05 parts by weight.

When the concentration is less than 0.005 parts by weight, the stability of the latex reagent due to the coating of the surface is not sufficient, and when it is more than 0.15 parts by weight, the dispersibility is too high and the measurement sensitivity becomes low. The concentration of the water-soluble polymer is 0.005 to 0.15 part by weight with respect to 1 part by weight of the carrier.

As the physiologically active substance which can be applied to the present invention and which is sensitized to the above water-insoluble carrier, a usual antigen or antibody is exemplified. The substance that is the antigen or antibody is
Examples are proteins, lipids, peptides or complexes thereof. The present invention is particularly effective for a substance which is difficult to acquire reactivity when sensitized to a carrier by itself, that is, a reagent sensitized with a hapten having a small molecular weight such as a lipid or a peptide. For example, it is a diagnostic agent for detecting antiphospholipid antibody in which latex particles are sensitized with a mixed solution of phospholipids as an antigen component.

Suitable examples of the antigen carried on the insoluble carrier are phospholipids and / or lipids.

The latex reagent of the present invention can be stored in an ordinary buffer solution. Known components such as phosphoric acid can be used as the component. The pH and ionic strength of the buffer solution can be used under normal physiological conditions. In addition, known substances that suppress non-specific reactions or promote antigen-antibody reactions can also be used in combination.

The latex reagent of the present invention can be stably stored in a suspension state for a long time, but can also be stored in a freeze-dried state. At that time, it is possible to use together with a general drug used as a stabilizer during freeze-drying.

As the means for detecting the agglutination degree of the latex reagent, any of a visual determination method, a method of measuring the change in the absorbance of the reaction solution with an apparatus, and the like can be used.

The immunoassay reagent according to the present invention can also constitute a kit for assaying antiphospholipid antibodies.

[0032]

[Function] By introducing a water-soluble polymer having a sugar chain into a water-insoluble carrier, the hydrophobicity of the water-insoluble carrier is locally increased, and the adsorption amount by the hydrophobic interaction of the antigen or antibody is increased. Hydrophilicity can be imparted to the insoluble carrier. This makes it possible to provide a diagnostic material in which non-specific aggregation is unlikely to occur.

[0033]

EXAMPLES The present invention will be described in more detail with reference to examples.

Example 1 Reagents and Serum (1) 10% (W / V) Polystyrene Latex Solution Polystyrene latex (Sekisui Chemical Co., Ltd., solid content 10%)
(W / V), average particle size 0.400 μm) were used as they were.

(2) Antigen solution: 2 ml of an ethanol solution of cardiolipin (manufactured by Sigma, special grade reagent, 5 mg / ml) and phosphatidylcholine (special grade reagent manufactured by Nacalai Tesque, Inc., reagent grade special) , 99%) and 10
10 ml of 10 mg / ml and 10 mg / ml of cholesterol (special grade reagent manufactured by Nacalai Tesque)
3 ml of the ethanol solution prepared in 1 above was mixed well and used as the antigen solution.

(3) Blocking buffer 100 mM Na₂HPO_Four(12 hydrate) and 10
0 mM Na₂HPO _Four(Dihydrate) is mixed to adjust the pH
Phosphate buffer adjusted to 7.40 (hereinafter 100 mM phosphorus
Glycosyl ethyl methacrylate in acid buffer)
Homopolymer (manufactured by Nippon Seika Co., average molecular weight 500,000, Gl
ucosylethylmethacryrate: hereinafter abbreviated as pGEMA)
1.0% (W / V), sodium azide (Nacalai Tes
KU Co., Ltd. special grade) to 0.1% (W / V)
Each dissolved product was used as a blocking buffer.

(4) Latex storage buffer 100 mM phosphate buffer in bovine serum albumin (Miles
Company, Fraction V, special grade reagent, abbreviated as BSA below) 1
% (W / V), sodium azide (manufactured by Nacalai Tesque, special grade reagent) 0.1% (W / V), ethylenediaminetetraacetic acid disodium dihydrate (manufactured by Nacalai Tesque,
Reagent special grade) was dissolved in 10 mM, and choline chloride (Nacalai Tesque, Inc. special reagent grade) was dissolved to 500 mM to prepare a latex storage buffer solution.

(5) Specimen dilution buffer solution 1.0% (W /
V) and BSA dissolved in 0.25% (W / V) and sodium azide in 0.1% (W / V) were used as sample dilution buffers.

(6) Syphilis-negative serum Serum collected from normal rabbits, negative by both the RPR-card test method (Chemical and Serum Therapy Research Institute) and Cerrodia TRHA kit (Fujirebio) What was judged to be used.

(7) Syphilis-positive serum Serum collected from rabbits experimentally inoculated with syphilis and syphilis, which are RPR-card test method (Chemical and Serum Therapy Research Institute) and Cerrodia TRHA The one determined to be positive by both kits (manufactured by Fujirebio) was used.

Preparation of reagents 0.1 ml of 10% (W / V) polystyrene latex solution
In a 8 ml polycarbonate tube, length 1 cm
0.25 ml of the antigen solution was added while stirring on a magnetic stirrer together with the star rubber of No. 1. After continuously stirring for 1 hour at room temperature, 2.0 ml of blocking buffer (1 part by weight of latex particles was added to pGEMA).
2 parts by weight) was added, and the mixture was subsequently stirred for 1.5 hours at room temperature. After that, with a high-speed cooling centrifuge (Hitachi HR26 type),
Centrifugal washing was performed at 19000 × g and 10 ° C. for 30 minutes. 2.0 ml of a buffer solution for latex storage was added to the obtained latex pellets, and they were stirred well. Further, 3.0 ml of a buffer solution for storing latex was added and stirred, and then centrifugal washing was performed with a high speed cooling centrifuge at 19000 × g and 10 ° C. for 30 minutes. This washing operation was repeated 3 times.

To the finally obtained pellet, 2.0 ml of a buffer solution for latex storage was added, and the mixture was sonicated in an ice crusher (Microchip, output scale 3, 50% cycle, manufactured by Astrason) in an ice bath, Sonicate for 1 minute and disperse.
After this, 6.0 ml of a latex storage buffer was further added and mixed well. Thus, the solid content 0.125
% (W / V) latex suspension was prepared and stored at 4 ° C.

Preparation of Specimens Among the syphilis-positive sera of rabbits prepared above, those showing 8 times by the RPR method were treated with physiological saline (0.9% NaCl aqueous solution) to give 2, 4, 8, 16 Dilute four times, 4, 2, 1,
A positive sample showing 0.5 times was prepared. In addition, physiological saline and syphilis-negative serum from normal rabbits were used as they were as negative samples.

Measurement of Specimen by Automatic Analyzer The method for measuring an antiphospholipid specimen in a specimen by a fully automatic biochemical analyzer Hitachi Model 7150 (manufactured by Hitachi, Ltd.) is shown below.

Measurement mode; Original Abs parameter; Specimen amount 20 μl Latex reagent amount 50 μl Specimen dilution buffer amount 350 μl Measurement wavelength; 570 nm measurement time; Specimen dilution buffer solution is added and mixed immediately after specimen dispensing, and then The latex reagent was added and mixed. The amount of change in the absorbance from 80 seconds to 320 seconds after the addition of the latex reagent was determined and used as the reaction amount.

Specimens: The syphilis-positive serum dilution series prepared above, physiological saline, and syphilis-negative sera were used as the specimens, and measurement was carried out at n = 2.

Example 2 In Example 1, pGEM in blocking buffer
The same operation as in Example 1 was performed except that the A concentration was 0.5% (W / V) (that is, 1 part by weight of pGEMA was added to 1 part by weight of latex particles).

Example 3 In Example 1, pGEM in blocking buffer
The same operation as in Example 1 was performed except that the A concentration was set to 0.1% (W / V) (that is, 0.2 part by weight of pGEMA was added to 1 part by weight of latex particles).

Example 4 In Example 1, pGEM in blocking buffer was used.
The same operation as in Example 1 was performed except that the A concentration was 0.05% (W / V) (that is, 0.1 part by weight of pGEMA was added to 1 part by weight of latex particles).

Comparative Example 1 In Example 1, pG was used as a blocking buffer.
The same operation as in Example 1 was carried out except that a buffer solution containing BSA at 1% (W / V) was used in place of EMA (that is, 1 part by weight of latex particles was used for BS.
2 parts by weight of A was added).

Comparative Example 2 In Example 1, pGEM in blocking buffer was used.
Example 1 except that the A concentration was 0.001% (W / V)
The same operation was performed (that is, 0.002 parts by weight of pGEMA was added to 1 part by weight of latex particles).

Comparative Example 3 In Example 1, pGEM in blocking buffer was used.
The same operation as in Example 1 was performed except that the A concentration was set to 4.0% (W / V) (that is, 8 parts by weight of pGEMA was added to 1 part by weight of latex particles).

Measurement Result 1 The amount of change in absorbed light intensity of each sample obtained in Examples 1 to 4 is shown in Table 1, and the amount of change in absorbed light intensity of each sample obtained in Comparative Examples 1 to 3 is shown in Table 1. Each is shown (in each case, an average value of n = 2).

[0054]

[Table 1]

[Table 2] As is clear from these tables, the reagents of Examples show higher sensitivity in positive sera and no non-specific reaction in negative sera, as compared with those in Comparative Examples.

Example 5 Reagents and Serum (1) 10% (W / V) Polystyrene Latex Solution Polystyrene latex (Sekisui Chemical Co., Ltd., solid content 10%)
(W / V), average particle size 0.400 μm) were used as they were.

(2) Antigen solution 2 ml of an ethanol solution of cardiolipin (manufactured by Sigma, special grade reagent, 5 mg / ml) and phosphatidylcholine (special grade reagent manufactured by Nacalai Tesque, Inc.) were added to ethanol (special grade reagent manufactured by Nacalai Tesque, Inc. , 99%) and 10
10 ml of 10 mg / ml and 10 mg / ml of cholesterol (special grade reagent manufactured by Nacalai Tesque)
3 ml of the ethanol solution prepared in 1 above was mixed well and used as the antigen solution.

(3) Latex dilution buffer 100 mM Na₂HPO_Four(12 hydrate) and 10
0 mM Na₂HPO _Four(Dihydrate) is mixed to adjust the pH
Phosphate buffer adjusted to 7.40 (hereinafter 100 mM phosphorus
Glycosyl ethyl methacrylate in acid buffer)
Homopolymer (manufactured by Nippon Seika Co., average molecular weight 500,000, Gl
ucosylethylmethacryrate: hereinafter abbreviated as pGEMA)
Latte that was dissolved to 0.1% (W / V)
Cux dilution buffer.

(4) Blocking buffer A blocking buffer was prepared by dissolving sodium azide (Nacalai Tesque, Inc., reagent grade) in the above 100 mM phosphate buffer to a concentration of 1% (W / V). And

(5) Latex storage buffer 100 mM phosphate buffer was added to bovine serum albumin (Miles
Company, Fraction V, special grade reagent, abbreviated as BSA below) 1
% (W / V), sodium azide (manufactured by Nacalai Tesque, special grade reagent) 0.1% (W / V), ethylenediaminetetraacetic acid disodium dihydrate (manufactured by Nacalai Tesque,
Reagent special grade) was dissolved in 10 mM, and choline chloride (Nacalai Tesque, Inc. special reagent grade) was dissolved to 500 mM to prepare a latex storage buffer solution.

(6) Specimen diluting buffer solution 100 mM phosphate buffer solution was added with 1.0% (W / pGEMA) of pGEMA.
V) and BSA were dissolved in 0.25% (W / V) and sodium azide were dissolved in 0.1% (W / V), respectively, to prepare a sample dilution buffer.

(7) Syphilis-negative serum Serum collected from normal rabbits, negative by both the RPR-card test method (Chemical and Serum Therapy Research Institute) and Cerrodia TRHA kit (Fujirebio) What was judged to be used.

(8) Syphilis-Positive Serum Serum collected from rabbits experimentally inoculated with syphilis and syphilis, which has RPR-card test (Chemical and Serum Therapy Research Institute) and Cerrodia TRHA The one determined to be positive by both kits (manufactured by Fujirebio) was used.

Preparation of Reagent 0.5 ml of 10% (W / V) polystyrene latex solution
A latex dilution buffer (0.1% (W / V) pGE
0.5 ml (including MA) (0.01 part by weight of pGEMA to 1 part by weight of latex particles) was mixed well. 0.1 ml of the obtained mixed solution was accurately dispensed into a polycarbonate tube of 8 ml, and the mixture was stirred on a magnetic stirrer with a 1 cm long star rubber,
0.25 ml of antigen solution was added. After continuously stirring at room temperature for 1 hour, 2.0 ml of blocking buffer was added, and subsequently stirred at room temperature for 1.5 hours. After that, with a high-speed cooling centrifuge (Hitachi HR26 type), 19000 × g,
Centrifugal washing was performed at 10 ° C. for 30 minutes. 2.0 ml of a buffer solution for latex storage was added to the obtained latex pellets, and they were stirred well. Further, a latex storage buffer solution 3.
Add 0 ml and stir, then in a high speed cooling centrifuge 1
Centrifugal washing was performed at 9000 × g and 10 ° C. for 30 minutes. This washing operation was repeated 3 times.

To the finally obtained pellet, 2.0 ml of a buffer solution for latex storage was added, and the mixture was sonicated in an ultrasonic crusher (Astrason, Microchip, output scale 3, 50% cycle) in an ice bath, Sonicate for 1 minute and disperse.
After this, 6.0 ml of a latex storage buffer was further added and mixed well. Thus, the solid content 0.125
% (W / V) latex suspension was prepared and stored at 4 ° C.

Preparation of Specimens Rabbit syphilis-positive sera prepared in the above, which showed 8 times the RPR method, were treated with physiological saline (0.9% NaCl aqueous solution) for 2, 4, 8, 16 Dilute four times, 4, 2, 1,
A positive sample showing 0.5 times was prepared. In addition, physiological saline and syphilis-negative serum from normal rabbits were used as they were as negative samples.

Measurement of Specimen by Automatic Analyzer The method for measuring an antiphospholipid specimen in a specimen by a fully automatic biochemical analyzer Hitachi Model 7150 (manufactured by Hitachi, Ltd.) is shown below.

Measurement mode; Original Abs parameter; Specimen amount 20 μl Latex reagent amount 50 μl Specimen dilution buffer amount 350 μl Measurement wavelength; 570 nm measurement time; Specimen dilution buffer solution is added and mixed immediately after specimen dispensing, and then The latex reagent was added and mixed. The amount of change in the absorbance from 80 seconds to 320 seconds after the addition of the latex reagent was determined and used as the reaction amount.

Specimens: The syphilis-positive serum dilution series prepared above, physiological saline, and syphilis-negative sera were used as the specimens, and measurement was carried out at n = 2.

Example 6 In Example 5, pGE in the latex dilution buffer was used.
The same operation as in Example 5 was carried out except that the MA concentration was 0.2% (W / V) (that is, 0.02 part by weight of pGEMA was added to 1 part by weight of latex particles).

Example 7 In Example 5, pGE in latex dilution buffer
The same operation as in Example 5 was carried out except that the MA concentration was changed to 0.5% (W / V) (that is, 0.05 part by weight of pGEMA was added to 1 part by weight of latex particles).

Comparative Example 4 In Example 5, p was used as the latex dilution buffer.
The same operation as in Example 5 was carried out except that a buffer solution containing BSA at 1% (W / V) was used in place of GEMA (that is, 1 part by weight of the latex particles was mixed with B.
0.1 part by weight of SA was added).

Comparative Example 5 In Example 5, pGE in a buffer for diluting latex was used.
Example 5 except that the MA concentration was 0.01% (W / V)
The same operation was performed (that is, 0.001 part by weight of pGEMA was added to 1 part by weight of latex particles).

Comparative Example 6 In Example 5, pGE in a latex dilution buffer was used.
The same operation as in Example 5 was performed except that the MA concentration was 2.0% (W / V) (that is, 0.2 part by weight of pGEMA was added to 1 part by weight of latex particles).

Measurement Results The amount of change in absorbed light intensity of each sample obtained in Examples 5 to 7 is shown in Table 3, and the amount of change in absorbed light intensity of each sample obtained in Comparative Examples 4 to 6 is shown in Table 4. Shown (all are average values of n = 2).

[0075]

[Table 3]

[Table 4] As is clear from these tables, the reagents of Examples show higher sensitivity in positive sera and no non-specific reaction in negative sera, as compared with those in Comparative Examples.

[0076]

INDUSTRIAL APPLICABILITY According to the present invention, by introducing a water-soluble polymer having a sugar chain into a water-insoluble carrier, the hydrophobicity of the water-insoluble carrier is locally enhanced, and the hydrophobic interaction of the antigen or antibody is caused. It is possible to increase the amount of adsorption and at the same time impart hydrophilicity to the water-insoluble carrier. As a result, it is possible to provide a reagent for immunoassay which has high sensitivity and can be stored for a long time without the risk of spontaneous aggregation or non-specific aggregation.

Claims (3)

[Claims] 1. An immunoassay reagent comprising a water-insoluble carrier carrying an antibody or an antigen, and a water-soluble polymer having a side chain having a saccharide introduced therein. 2. A water-insoluble carrier is loaded with an antibody or an antigen, and then an aqueous solution containing the carrier and the antibody or the antigen is added with a water-soluble polymer having a saccharide in a side chain in an amount of 0.01 to 1 part by weight of the carrier. A method for producing an immunoassay reagent, which comprises adding an aqueous solution containing a concentration of 4 parts by weight. 3. When supporting an antibody or an antigen on a water-insoluble carrier, before or at the same time as carrying, the water-soluble polymer having a saccharide in a side chain is added to an aqueous liquid containing the carrier in an amount of 0 per 1 part by weight of the carrier. A method for producing an immunoassay reagent, which comprises adding an aqueous solution containing such a concentration as to give 0.005 to 0.15 parts by weight.