CN111122845A

CN111122845A - Chemiluminescence immunoassay kit for resisting biotin interference and application thereof

Info

Publication number: CN111122845A
Application number: CN201811458647.3A
Authority: CN
Inventors: 章春奇; 金鑫; 赵卫国; 刘宇卉; 李临; 其他发明人请求不公开姓名
Original assignee: Beyond Diagnostics Shanghai Co ltd; Chemclin Diagnostics Corp
Current assignee: Beyond Diagnostics Shanghai Co ltd; Chemclin Diagnostics Corp
Priority date: 2018-10-31
Filing date: 2018-11-30
Publication date: 2020-05-08

Abstract

The invention relates to a chemiluminescence immunoassay kit for anti-biotin interference and application thereof in the technical field of chemiluminescence immunoassay. The kit comprises: a) the anti-interference agent comprises a carrier and an active molecule, wherein the carrier is a porous medium, and the active molecule is filled in the carrier and can be specifically combined with a biotin molecule; b) an immune molecule capable of immunological binding to a target molecule to be detected; c) a chemiluminescent reagent. The kit comprises an anti-interference agent, and the anti-interference agent takes an active molecule capable of being specifically combined with a biotin molecule as an object molecule and is filled in a carrier in a proper mode to form a mesoporous assembly object-host system, so that the kit avoids false positive or false negative results caused by free biotin.

Description

Chemiluminescence immunoassay kit for resisting biotin interference and application thereof

Technical Field

The invention belongs to the technical field of chemiluminescence immunoassay, and particularly relates to a chemiluminescence immunoassay kit for anti-biotin interference and application thereof.

Background

The Biotin-Avidin System (BAS) is a new type of amplification System for biological reactions developed in the late 70 s. The BAS system has the advantages of high affinity, high sensitivity, high stability and the like. Combining the two to couple macromolecular bioactive substances such as antigen and antibody. Their combination is rapid, specific, stable and has multi-stage amplification effect. At present, the BAS system is mainly applied to the fields of immunology, molecular biology and the like. The method is particularly advantageous in the practical application of in vitro diagnosis, and the greatest defect of the method is that the interference of biotin causes detection errors.

Biotin interference may produce false positives and may also produce false negatives. Generally, the sandwich method produces false negatives and the competition method produces false positives. The current common solutions are: 1. replacing platforms that do not use an avidin-biotin system; 2. retesting every other day or after one week after the withdrawal of the relevant drugs/foods; 3. sample pretreatment: the streptavidin-coated microparticles remove the biotin from the sample.

However, there is no method that can solve the problem of biotin interference well in the avidin-biotin system.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides an anti-biotin-interference chemiluminescence immunoassay kit which can well solve the problem of biotin interference.

To this end, the present invention provides in a first aspect an anti-biotin interference chemiluminescent immunoassay kit comprising:

a) the anti-interference agent comprises a carrier and an active molecule, wherein the carrier is a porous medium, and the active molecule is filled in the carrier and can be specifically combined with a biotin molecule;

b) an immune molecule capable of immunological binding to a target molecule to be detected;

c) a chemiluminescent reagent.

In some embodiments of the invention, the anti-interference agent is capable of recognizing both free biotin molecules and biotin conjugates.

In some preferred embodiments of the invention, the anti-interference agent is capable of selectively adsorbing free biotin molecules.

In some embodiments of the invention, the free biotin molecule is capable of diffusing into the carrier and specifically binding to the active molecule therein.

In other embodiments of the invention, the anti-interference agent is capable of restricting the entry of a biological macromolecule larger in size than the active molecule into its carrier.

In some embodiments of the invention, the anti-interference agent is capable of being uniformly distributed in a liquid phase reaction system.

In some embodiments of the invention, the support has an internal surface area greater than its external surface area; preferably, the internal surface area of the support is more than 5 times, preferably more than 10 times, more preferably more than 20 times the external surface area thereof.

In other embodiments of the present invention, the particle size of the support is 15 to 300nm, preferably 30 to 250nm, more preferably 50 to 200 nm.

In some embodiments of the invention, the support has a specific surface area of 200m²A ratio of one to more than g, preferably 400m²More preferably 600 m/g or more²More than g, most preferably 1000m²More than g.

In other embodiments of the present invention, the support has a minimum porosity of greater than 40%, preferably greater than 50%, more preferably greater than 60%.

In some embodiments of the invention, the porous medium is selected from one or more of a porous metal material, a porous non-metal material, and a porous polymer material.

In other embodiments of the present invention, the support is a mesoporous microsphere, preferably an ordered mesoporous microsphere.

In some embodiments of the present invention, the pore size of the mesoporous microsphere is 2 to 50nm, preferably 4 to 30nm, and more preferably 5 to 15 nm.

In other embodiments of the present invention, the mesoporous microsphere is a cage-shaped hollow mesoporous microsphere.

In some preferred embodiments of the present invention, the mesoporous microspheres are selected from Al₂O₃Mesoporous material and WO₃Mesoporous material and TiO₂Mesoporous material, ZrO₂At least one of the mesoporous material, the silicon-based mesoporous material and/or the mesoporous carbon material is preferably selected from silicon-based mesoporous materials.

In some embodiments of the invention, the active molecule is selected from avidin and/or streptavidin.

In other embodiments of the present invention, the active molecule is packed in the carrier by physical adsorption.

In some preferred embodiments of the invention, the active molecule is loaded into the carrier by contacting the carrier in a system comprising a buffer.

In some embodiments of the invention, the pH of the buffer-containing system is 7 to 9, preferably 7.1 to 8.0, more preferably 7.2 to 7.8, and even more preferably 7.3-7.6.

In some embodiments of the invention, the active molecule is loaded into the carrier by direct or indirect chemical crosslinking.

In some preferred embodiments of the present invention, the inner surface of the carrier is modified with a chemical group, and the active molecule is filled in the carrier by covalent coupling with the chemical group; wherein the chemical group is selected from one or more of carboxyl, aldehyde group, amino, sulfhydryl and hydroxyl.

In some embodiments of the present invention, the carrier has a biotin molecule attached to its inner surface, and the active molecule is filled in the carrier by specific binding to the biotin molecule.

In some embodiments of the invention, the anti-interference agent further comprises a buffer solution, preferably a PBS buffer solution.

In other embodiments of the invention, the total concentration of the carrier and the active molecule filled in the carrier in the anti-interference agent is 5-50ug/mL, preferably 8-30ug/mL, more preferably 10-20 ug/mL.

In some embodiments of the present invention, the preparation method of the anti-interference agent comprises: step S1, contacting the carrier with the active molecule; preferably, the contacting is performed in a first buffer system.

In some preferred embodiments of the present invention, the preparation method of the anti-interference agent further includes step S0: the carrier is washed with the second buffer system, and step S0 is performed before step S1.

In other preferred embodiments of the present invention, the method for preparing the anti-interference agent further includes step S2: removing the active molecules not filled into the carrier, step S2 being performed after step S1; preferably, the active molecules not filled in the carrier are removed by adding a third buffer solution system to the carrier treated in step S1 and then performing solid-liquid separation.

In some embodiments of the invention, the kit further comprises a biotin conjugate comprising a substance that binds directly or indirectly to biotin and participates in an immune response.

In other embodiments of the invention, the biotin conjugate is a biotin-binding antibody and/or a biotin-binding antigen.

In some embodiments of the invention, the kit is a homogeneous chemiluminescent immunoassay kit.

In other embodiments of the invention, the kit is a heterogeneous chemiluminescent immunoassay kit comprising a solid support.

In some embodiments of the invention, the kit comprises the following components:

a component L comprising a solid support and a first immune molecule directly or indirectly bound thereto, said first immune molecule being capable of binding to a first epitope of a target molecule to be detected;

a component M comprising a chemiluminescent reagent capable of reacting with a substrate or capable of catalyzing the generation of a detectable signal by a substrate and a second immune molecule directly or indirectly bound thereto, the second immune molecule being capable of binding to a second epitope of a target molecule to be detected, the second epitope and the first epitope not overlapping.

In other embodiments of the invention, the kit comprises the following components:

a component M comprising a first chemiluminescent reagent capable of reacting with a substrate or capable of catalyzing the substrate to generate a detectable signal and a second immune molecule directly or indirectly bound thereto, the second immune molecule capable of binding to a second epitope of a target molecule to be detected, the second epitope and the first epitope not overlapping;

component N comprising a second chemiluminescent reagent capable of reacting with the substrate or capable of catalyzing the substrate to generate a detectable signal and a third immune molecule directly or indirectly bound thereto, said third immune molecule capable of binding to a second epitope of the target molecule to be detected, said second epitope and said first epitope not overlapping.

In some embodiments of the invention, the solid support is selected from magnetic microspheres, plastic microparticles, microwell plates, glass, capillaries, or nylon; preferably selected from magnetic microspheres.

In other embodiments of the present invention, the magnetic microspheres have a particle size of 0.05 to 50 microns; preferably 0.1 to 40 microns; more preferably 5-20 microns.

In some embodiments of the invention, the label is a chemiluminescent label and the chemiluminescent reagent is selected from luminol and its derivatives, isoluminol and its derivatives, acridinium ester and its derivatives, adamantane, rare earth elements, or ruthenium bipyridine complexes.

In other embodiments of the invention, the chemiluminescent reagent is a chemiluminescent catalyst selected from the group consisting of horseradish peroxidase and alkaline phosphatase.

In some embodiments of the invention, the first immune molecule is bound to one member of a specific binding pair member and the solid support is bound to the other member of the specific binding pair member; preferably, the first antibody or binding fragment thereof is bound to biotin and the solid support is bound to streptavidin.

In other embodiments of the invention, the second antibody or binding fragment thereof binds to one member of a specific binding pair member and the chemiluminescent reagent binds to the other member of the specific binding pair member; preferably, the second antibody or binding fragment thereof is bound to biotin and the chemiluminescent reagent is bound to streptavidin.

In a second aspect, the invention provides a use of the kit according to the first aspect of the invention in the detection of a biotin-streptavidin system; preferably in thyroid function detection; further preferred is the use in the detection of triiodothyronine and/or tetraiodothyronine.

The invention has the beneficial effects that: the kit comprises an anti-interference agent, and active molecules such as SA or avidin protein molecules and the like are used as 'guest molecules' and are filled in pores of a porous medium in a proper mode to form a 'mesoporous assembly host-guest' system, so that free biotin molecules and biotin conjugates can be effectively distinguished, the interference of the free biotin can be eliminated, and false positive and/or false negative results in chemiluminescence immunoassay are avoided. In addition, the kit disclosed by the invention also has practicability and universality, can be applied to different technical platforms, and has small influence on the performance of the reagent.

Detailed Description

In order that the invention may be readily understood, a detailed description of the invention is provided below. However, before the invention is described in detail, it is to be understood that this invention is not limited to particular embodiments described. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

Where a range of values is provided, it is understood that each intervening value, to the extent that there is no stated or intervening value in that stated range, to the extent that there is no such intervening value, is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where a specified range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.

Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, the preferred methods and materials are now described.

I. Term(s) for

The term "homogeneous" as used herein is defined in english as "homogeneous" and means that the bound antigen-antibody complex and the remaining free antigen or antibody are detected without separation.

The English corresponding to the term "heterogeneous" is defined as "heterogeneous immunoassay" in the present invention, which means that in the operation process of labeling with fluorescent substance, radionuclide, enzyme or chemiluminescent substance, various related reagents are mixed and reacted, then need to be separated, and the substance to be detected is separated from the reaction system and then detected.

The term "carrier" as used herein refers to a substance capable of carrying active molecules together to participate in a chemical or physical process. The chemical composition of the carrier in the present invention is not particularly limited, and may be organic or inorganic, such as high molecular polymer, metal, glass, mineral salt, diatom, phospholipid vesicle, silicon particle, microcrystalline dye, etc.

The term "porous medium" as used herein refers to a substance composed of a skeleton composed of a solid substance and a plurality of fine voids densely grouped and partitioned by the skeleton.

The term "active molecule" as used herein refers to a molecule having the ability to specifically bind to a biotin molecule. Exemplary reactive molecules are avidin and streptavidin.

The term "target molecule to be detected" as used herein refers to a substance in a sample to be detected during detection. One or more substances having a specific binding affinity for the target molecule to be detected will be used for the detection of the target molecule. The target molecule to be detected may be a protein, a peptide, an antibody or a hapten which allows it to bind to an antibody.

The term "antibody" as used herein is used in the broadest sense and includes antibodies of any isotype, antibody fragments that retain specific binding to an antigen, including but not limited to Fab, Fv, scFv, and Fd fragments, chimeric antibodies, humanized antibodies, single chain antibodies, bispecific antibodies, and fusion proteins comprising an antigen-binding portion of an antibody and a non-antibody protein.

The term "antigen" as used herein refers to a substance that stimulates the body to produce an immune response and that binds to the immune response product antibodies and sensitized lymphocytes in vitro and in vivo to produce an immune effect.

The term "binding" as used herein refers to direct association between two molecules due to interactions such as covalent, electrostatic, hydrophobic, ionic and/or hydrogen bonding, including but not limited to interactions such as salt and water bridges.

The term "specific binding" as used herein refers to the mutual discrimination and selective binding reaction between two substances, and is the conformation correspondence between the corresponding reactants in terms of the three-dimensional structure.

The term "active oxygen" as used herein refers to a general term for a substance which is composed of oxygen, contains oxygen, and is active in nature, and is mainly an excited oxygen molecule, including superoxide anion (O) which is an electron reduction product of oxygen₂(-) and the two-electron reduction product hydrogen peroxide (H)₂O₂) The three-electron reduction product hydroxyl radical (. OH) and nitric oxide and singlet oxygen (1O)₂) And the like.

In the present invention, the term "acceptor" refers to a substance capable of reacting with reactive oxygen species to generate a detectable signal. When the donor is induced by energy or an active compound to activate and release a high-energy state of reactive oxygen species, the high-energy state of reactive oxygen species can be trapped by a close-proximity acceptor, thereby transferring energy to activate the acceptor. In some embodiments of the invention, the acceptor is a substance that undergoes a chemical reaction with reactive oxygen species (e.g., singlet oxygen) to form an unstable metastable intermediate that can decompose with or following luminescence. Typical examples of such substances include, but are not limited to: enol ether, enamine, 9-alkylidene xanthan gum, 9-alkylidene-N-alkyl acridin, aromatic vinyl ether, diepoxy ethylene, dimethyl thiophene, aromatic imidazole or lucigenin. In other embodiments of the invention, the acceptor is an olefin capable of reacting with a reactive oxygen species (e.g., singlet oxygen) to form a hydroperoxide or dioxetane that can be decomposed into ketones or carboxylic acid derivatives; a stable dioxetane which can be decomposed by the action of light; acetylenes that can react with reactive oxygen species (e.g., singlet oxygen) to form diketones; hydrazones or hydrazides which can form azo compounds or azocarbonyl compounds, such as luminol; and aromatic compounds that can form endoperoxides. Specific, non-limiting examples of receptors that can be utilized in accordance with the disclosed and claimed invention are described in U.S. patent No. US5340716, which is incorporated herein by reference in its entirety. In other embodiments of the invention, the receptor comprises an olefinic compound and a metal chelate, which is non-particulated and soluble in an aqueous medium, as in the case of the receptor described in patent PCT/US2010/025433 (which is incorporated herein by reference in its entirety).

In the present invention, the "chemiluminescent compound", i.e., a compound referred to as a label, may undergo a chemical reaction to cause luminescence, such as by being converted to another compound formed in an electronically excited state. The excited state may be a singlet state or a triplet excited state. The excited state may relax to the ground state to emit light directly, or may return to the ground state itself by transferring excitation energy to an emission energy acceptor. In this process, the energy-acceptor microsphere will be transitioned to an excited state to emit light.

The phrase "capable of binding, directly or indirectly," means that the specified entity is capable of specifically binding to the entity (directly), or that the specified entity is capable of specifically binding to a specific binding pair member, or a complex having two or more specific binding partners capable of binding to other entities (indirectly).

The "specific binding pair member" of the present invention is selected from the group consisting of (1) a small molecule and a binding partner for the small molecule, and (2) a large molecule and a binding partner for the large molecule.

In the present invention, the term "donor" refers to a sensitizer capable of generating a reactive intermediate such as singlet oxygen that reacts with an acceptor upon activation by energy or an active compound. The donor may be photoactivated (e.g., dyes and aromatic compounds) or chemically activated (e.g., enzymes, metal salts, etc.). In some embodiments of the invention, the donor is a photosensitizer which may be a photosensitizer known in the art, preferably a compound that is relatively light stable and does not react efficiently with singlet oxygen, non-limiting examples of which include compounds such as methylene blue, rose bengal, porphyrins, phthalocyanines, and chlorophylls disclosed in, for example, U.S. Pat. No. 5,5709994, which is incorporated herein by reference in its entirety, as well as derivatives of these compounds having 1 to 50 atom substituents that serve to render these compounds more lipophilic or more hydrophilic, and/or as a linker group for attachment to a specific binding partner. Examples of other photosensitizers known to those skilled in the art may also be used in the present invention, such as those described in US patent No. US6406913, which is incorporated herein by reference. In other embodiments of the invention, the donor is a chemically activated other sensitizer, non-limiting examples of which are certain compounds that catalyze the conversion of hydrogen peroxide to singlet oxygen and water. Other examples of donors include: 1, 4-dicarboxyethyl-1, 4-naphthalene endoperoxide, 9, 10-diphenylanthracene-9, 10-endoperoxide, etc., which are heated or which absorb light directly to release active oxygen (e.g., singlet oxygen).

Photosensitizers generally activate chemiluminescent compounds by irradiating the medium containing the reactant. The medium must be irradiated with light having a wavelength and an energy sufficient to convert the photosensitizer to an excited state, thereby enabling it to activate molecular oxygen to singlet oxygen. The excited state of a photosensitizer capable of exciting molecular oxygen is generally in the triplet state, which is about 20Kcal/mol, usually at least 23Kcal/mol higher than the energy of the photosensitizer in the ground state. Preferably, the medium is irradiated with light having a wavelength of about 450 and 950nm, although shorter wavelengths, such as 230 and 950nm, may be used. The light generated can be measured in any conventional manner, such as by photography, visual inspection, photometer, etc., to determine its amount relative to the amount of analyte in the medium. The photosensitizer is preferably relatively non-polar to ensure solubility into the lipophilic member.

The photosensitizer and/or chemiluminescent compound may be selected to be dissolved in, or non-covalently bound to, the surface of the particle. In this case, the compounds are preferably hydrophobic to reduce their ability to dissociate from the particles, thereby allowing both compounds to bind to the same particle.

Detailed description of the preferred embodiments

The present invention will be described in more detail below.

The kit comprises an anti-interference agent, and the anti-interference agent takes an active molecule capable of being specifically combined with a biotin molecule as an object molecule and is filled in a carrier in a proper mode to form a mesoporous assembly object-host system, so that the kit avoids false positive or false negative results caused by free biotin.

The invention relates to an anti-biotin interference chemiluminescence immunoassay kit in a first aspect, which comprises:

c) a chemiluminescent reagent. The expression "the active molecule is filled in the carrier" means that the active molecule is located in a void in the carrier, and may or may not be in contact with the skeleton.

In some embodiments of the invention, the anti-interference agent is capable of recognizing both free biotin molecules and biotin conjugates. In the present invention, "recognition" may mean that the active molecule in the anti-interference agent is combined with the free biotin molecule and/or biotin conjugate through the synergistic effect of intermolecular forces.

In some embodiments of the invention, the free biotin molecule is capable of diffusing into the carrier and specifically binding to the active molecule therein. In the present invention, the "diffusion" may mean that free biotin molecules are dispersed into a carrier due to random movement of the molecules.

In some embodiments of the invention, the vector satisfies at least one of the following conditions: a) the inner pores of the carrier have a sufficiently large surface area (far exceeding the surface area of the carrier), and the voids can only allow the entry of active molecules, but limit the larger proteins of the active molecules, such as antibodies or large antigens, etc.; b) active molecules such as SA or avidin can be filled in the carrier, for example, inside the voids, by a chemical or physical adsorption method; c) the carrier can be stably and uniformly distributed in a solution (e.g., an aqueous solution) without precipitation.

In some embodiments of the invention, the support has an internal surface area greater than its external surface area; preferably, the internal surface area of the support is more than 5 times, preferably more than 10 times, more preferably more than 20 times the external surface area thereof. In some preferred embodiments of the invention, the internal surface area of the support is a multiple of its external surface area including, but not limited to: 5 times, 6 times, 8 times, 10 times, 12 times, 16 times, 18 times, 20 times, 22 times, 24 times, 26 times, 28 times, or 30 times.

In other embodiments of the present invention, the particle size of the carrier is 15-300nm, such as 15nm, 20nm, 25nm, 30nm, 40nm, 50nm, 100nm, 250nm, 300nm, etc., preferably 30-250nm, more preferably 50-200 nm. Too large a carrier particle size can cause the carrier to settle too quickly, which is not conducive to forming a stable, uniform solution.

In some embodiments of the invention, the support has a specific surface area of 200m²Per g or more, e.g. 200m²/g、400m²/g、600m²/g、800m²/g、1000m²/g、1200m²/g、1500m²(ii) a ratio of the total of the components in the formula,/g,preferably 400m²More preferably 600 m/g or more²More than g, most preferably 1000m²More than g.

In some embodiments of the present invention, the pore size of the mesoporous microsphere is 2 to 50nm, such as 2nm, 5nm, 10, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 50nm, etc., preferably 4 to 30nm, and more preferably 5 to 15 nm.

The silicon-based mesoporous material is made of SiO₂(CH₂)₂Periodic mesoporous material composed of tetrahedral structural units. The mesoporous silica materials can be microscopically classified into two types: one is disordered mesoporous solids represented by silica xerogels and aerogels. The disordered mesoporous silica can be powder, block, sheet or film in macroscopic view. The other is an ordered mesoporous silica represented by MCM 41. The ordered mesoporous silica has the structural characteristics that the pore size is uniform, the ordered mesoporous silica is arranged in a hexagonal order, and the pore size of the mesoporous silica can be adjusted between 2nm and 10 nm. Because the hole wall is thin, the silicon-based unit has low alternating current degree and poor hydrothermal stability. The specific surface area can reach 1000m²(ii) in terms of/g. Also, the SBA series, HMM series, TUD series, FSM series,KIT series, CMK series, FDU series, starbon, etc. Among them, SBA-15 has more research, and the hydrothermal stability of the material is better than that of MCM series. The aperture is adjustable between 5nm and 30 nm. HMM is a spherical mesoporous material, the aperture of which is 4-15nm, and the outer diameter of which is 20-80nm and is adjustable.

In some embodiments of the invention, the active molecule is selected from avidin and/or streptavidin. Avidin is a glycoprotein extracted from egg white, has a molecular weight of about 60kD, is composed of 4 subunits per molecule, and can be closely bound to 4 biotin molecules. Such avidin includes, but is not limited to: avidin, streptavidin, vitellin, and avidin-like. Streptavidin (SA), a protein with biological properties similar to those of avidin (A), is a protein product secreted by Streptomyces avidins during culture, and SA can also be produced by genetic engineering means. The molecular weight of SA is 65000, and consists of 4 peptide chains with the same sequence, and each SA peptide chain can combine with 1 biotin molecule. Thus, like avidin, each SA molecule also has 4 binding sites for biotin molecules with a binding constant of 1015mol/L as avidin.

In other embodiments of the present invention, the active molecule is packed in the carrier by physical adsorption. Physical adsorption, also known as van der waals adsorption, is caused by intermolecular forces between the adsorbate and the adsorbent, also known as van der waals forces.

In other embodiments of the invention, the total concentration of the carrier and the active molecule filled in the carrier in the anti-interference agent is 5-50ug/mL, such as 5ug/mL, 10ug/mL, 15ug/mL, 20ug/mL, 25ug/mL, 30ug/mL, 35ug/mL, 40ug/mL, 45ug/mL, 50ug/mL, etc., preferably 8-30ug/mL, more preferably 10-20 ug/mL.

In some embodiments of the present invention, the preparation method of the anti-interference agent comprises: step S1, contacting the carrier with the active molecule; preferably, the contacting is performed in a first buffer system. In some embodiments of the above method, the pH of the first buffer system is from 7.0 to 9, preferably from 7.1 to 8.0, more preferably from 7.2 to 7.8, still more preferably from 7.3 to 7.7, further preferably from 7.35 to 7.50, and most preferably 7.40. In this embodiment, examples of the pH of the first buffer system include 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 9.0, and the like.

In some embodiments of the above method, the pH of the first buffer system is from 7.0 to 9, preferably from 7.1 to 8.0, more preferably from 7.2 to 7.8, still more preferably from 7.3 to 7.7, further preferably from 7.35 to 7.50, and most preferably 7.40. In this embodiment, examples of the pH of the first buffer system include 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 9.0, and the like.

In still other embodiments of the above method, the pH of the first buffer system is from 3.0 to 7.0, preferably from 3.5 to 6.8, more preferably from 4.0 to 6.5, even more preferably from 5.0 to 6.4, even more preferably from 5.5 to 6.3, and most preferably 6.0. In this embodiment, examples of the pH of the first buffer system include 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, and the like.

According to some embodiments, the method further comprises step S0: the carrier is washed with the second buffer system, and step S0 is performed before step S1. In some embodiments of the above method, the pH of the second buffer system is from 7.0 to 9, preferably from 7.1 to 8.0, more preferably from 7.2 to 7.8, still more preferably from 7.3 to 7.7, further preferably from 7.35 to 7.50, and most preferably 7.40. In this embodiment, examples of the pH of the first buffer system include 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 9.0, and the like. In still other embodiments of the above method, the pH of the second buffer system is from 3.0 to 7.0, preferably from 3.5 to 6.8, more preferably from 4.0 to 6.5, even more preferably from 5.0 to 6.4, even more preferably from 5.5 to 6.3, and most preferably 6.0. In this embodiment, examples of the pH of the first buffer system include 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, and the like.

According to some embodiments, the method further comprises step S2: the active molecules not filled in the carrier are removed, and step S2 is performed after step S1. Preferably, the active molecules not filled in the carrier are removed by adding a third buffer solution system to the carrier treated in step S1 and then performing solid-liquid separation.

In some embodiments of the above methods, the pH of the third buffer system is from 7.0 to 9, preferably from 7.1 to 8.0, more preferably from 7.2 to 7.8, even more preferably from 7.3 to 7.7, even more preferably from 7.35 to 7.50, and most preferably 7.40. In this embodiment, examples of the pH of the third buffer system include 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 9.0, and the like. In still other embodiments of the above method, the pH of the third buffer system is from 3.0 to 7.0, preferably from 3.5 to 6.8, more preferably from 4.0 to 6.5, even more preferably from 5.0 to 6.4, even more preferably from 5.5 to 6.3, and most preferably 6.0. In this embodiment, examples of the pH of the third buffer system include 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, and the like.

In some embodiments of the above methods, the first buffer system comprises one or more selected from the group consisting of a phosphate buffer, a piperazine-1, 4-diethylsulfonic acid buffer, a 3-morpholinopropanesulfonic acid buffer, a 4-hydroxyethylpiperazine ethanesulfonic acid buffer, and a 3- (hydroxyethylpiperazine) -2-hydroxypropanesulfonic acid buffer. In some embodiments of the above methods, the second buffer system comprises one or more selected from the group consisting of a phosphate buffer, a piperazine-1, 4-diethylsulfonic acid buffer, a 3-morpholinopropanesulfonic acid buffer, a 4-hydroxyethylpiperazine ethanesulfonic acid buffer, and a 3- (hydroxyethylpiperazine) -2-hydroxypropanesulfonic acid buffer. In some embodiments of the above methods, the third buffer system comprises one or more selected from the group consisting of a phosphate buffer, a piperazine-1, 4-diethylsulfonic acid buffer, a 3-morpholinopropanesulfonic acid buffer, a 4-hydroxyethylpiperazine ethanesulfonic acid buffer, and a 3- (hydroxyethylpiperazine) -2-hydroxypropanesulfonic acid buffer.

In some embodiments of the above methods, the third buffer system further comprises a surfactant. According to some embodiments, the surfactant comprises one or more selected from the group consisting of Tween-20, Tween-80, Triton X-405, Triton X-100, BRIJ 35 and Pluronic L64. According to some embodiments, the surfactant comprises tween-20.

In some embodiments of the above method, the contacting temperature is 0-50 ℃, preferably 20-40 ℃, such as 25-30 ℃ (i.e., room temperature) in step S1; and/or the contact time is 6-24 hours, preferably 8-12 hours, such as 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, etc. In some other embodiments of the above method, the contacting temperature is from 0 to 50 ℃, preferably from 20 to 40 ℃, e.g., from 25 to 30 ℃ (i.e., room temperature); and/or the contact time is 1 to 10 hours, preferably 2 to 6 hours, such as 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, etc.

In some embodiments of the above method, further comprising step S3, adding a fourth buffer system. Preferably, the fourth buffer system comprises one or more selected from the group consisting of a phosphate buffer, a piperazine-1, 4-diethylsulphonic acid buffer, a 3-morpholinopropanesulphonic acid buffer, a 4-hydroxyethylpiperazine ethanesulphonic acid buffer and a 3- (hydroxyethylpiperazine) -2-hydroxypropanesulphonic acid buffer.

The second aspect of the present invention relates to the use of the kit according to the first aspect of the present invention in the detection of the biotin-streptavidin system; preferably in thyroid function detection; further preferred is the use in the detection of triiodothyronine and/or tetraiodothyronine.

Example III

In order that the present invention may be more readily understood, the following detailed description will proceed with reference being made to examples, which are intended to be illustrative only and are not intended to limit the scope of the invention. The starting materials or components used in the present invention may be commercially or conventionally prepared unless otherwise specified.

Reagents and instrumentation:

SA (Sigma Aldrich), carboxyl-functionalized silica-based microspheres (particle size 15-200nm, pore size 2-15nm, Sigma Aldrich), phosphate buffer (0.02M PBS, pH 7.4), 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride EDAC (thermo fisher), Tween-20, 0.1M MES buffer (pH 6.0), biotin (D-biotin), ProteinG affinity column (GE), serotonin serum, triiodothyronine (T3) detection kit (Boyang Biotech (Shanghai) Co., Ltd.), light-activated chemiluminescence assay system general-purpose solution (photosphere solution/streptavidin labeled donor solution). LiCA HT (boyang biotechnology (shanghai) ltd), hitachi high-speed refrigerated centrifuge, and the like.

The anti-interference agent is prepared by a physical adsorption mode

Example 1

In the first step, 10mg of carboxyl-functionalized silica-based microspheres (particle size 15nm, pore size 2nm) were taken in a 2mL centrifuge tube, 0.02M PBS (pH 7.4) buffer was added, centrifuged at 10000rpm at 4 ℃ and washed once for 15 min.

And secondly, adding 200uL PBS buffer solution, performing ultrasonic dispersion uniformly, adding 150uL 10mg/mL SA water solution, supplementing the PBS buffer solution until the microsphere reaction concentration is 20mg/mL, and stirring at room temperature overnight.

Thirdly, centrifuging the SA microspheres by using 0.02M PBS (pH 7.4) buffer solution containing 0.5% Tween-20, centrifuging at 10000rpm at 4 ℃, washing for three times, removing unadsorbed SA, and finally diluting to 10mg/mL by using 0.02M PBS (pH 7.4) buffer solution.

Examples 2 to 7

The preparation method is the same as example 1, except that carboxyl-functionalized silica-based microspheres with different particle sizes and/or pore sizes are used in each example (see table 1).

Covalent coupling method for preparing anti-interference agent

Example 8 (covalent coupling mode)

In the first step, 10mg of carboxyl functionalized silica-based microspheres were taken in a 2mL centrifuge tube and washed once with 0.1M MES (pH 6.0) buffer at 4 ℃ at 10000rpm for 15 min.

In the second step, 200uL of 0.1M MES (pH 6.0) buffer was added and dispersed by sonication, followed by 150uL of 10mg/mL SA in water, followed by 100uL of 10mg/mLEDAC (0.1M MES) solution and stirring at room temperature for 4 h.

Thirdly, the SA microspheres are centrifugally washed three times by using 0.02M PBS (pH 7.4) buffer solution containing 0.5% Tween-20 to remove unadsorbed SA, and finally, the volume is adjusted to 10mg/mL by using PBS buffer solution.

Example 9: effect evaluation of the chemiluminescence immunoassay kit for anti-biotin interference

The experimental steps are as follows:

1. a concentrated solution of T3 was added to the serum of degerming serum to prepare a solution of T3 at concentrations of 1nmol/L and 2 nmol/L.

2. A40 ug/mL solution of beads was prepared and solutions of different concentrations (diluted in PBS) were prepared using the anti-interference agents prepared in examples 1-7, as shown in Table 1.

3. Biotin was added to the above T3 solution to prepare sample solutions having biotin concentrations of 0 and 128ng/ml, respectively.

4. Adding 25uL of sample solution, sequentially adding 25uL of reagent I (containing diiodothyronine coated receptor solution) and reagent II (containing biotin labeled anti-triiodothyronine antibody solution) in the T3 kit (manually adding 25uL of sample solution, 25uL of reagent I and 25uL of reagent II according to the reaction mode), and adding 25uL of the anti-interference agent solution prepared in the step 2 according to the following table 1, wherein the anti-interference agent is not added in the conditions 1 and 2.

5. Put into LICA HT, a first stage incubation is performed: incubate at 37 ℃ for 17 min.

6. Add 175ul of universal solution (containing streptavidin labeled donor) manually.

7. Performing a second stage incubation: incubation is carried out for 15min at 37 ℃ and the corresponding sample to be tested is obtained after incubation.

8. And exciting the sample to be detected by using energy and reading the generated luminescent signal. See tables 2 and 3 for reading results.

TABLE 1

TABLE 2 TABLE 3

And (3) data analysis:

when the concentration of T3 is 1nM and the concentration of biotin is 128ng/mL, the signal of chemiluminescence immune response drops by 89%, and biotin interference is severe. When the microspheres with the pore diameter of 2nm (the number 3 in the table 1) are added, the luminescent signals are almost not obviously changed, and when the microspheres with the particle diameters of 50nm, the pore diameters of 5nm and 10nm (the numbers 4 and 5 in the table 1) are adopted, the luminescent signals are improved to a certain extent, and the falling amplitude is 50-70%.

When the particle size and the aperture are not changed, the concentration of the anti-interference agent is increased to 10ug/mL (serial numbers 5 and 6 in Table 1 are compared), the luminous signal is further increased, and the falling amplitude is about 25%. When the aperture is 10nm and the concentration is 10ug/ml, and the particle size of the microsphere is increased to 100nm (serial numbers 6 and 7 in table 1), the drop amplitude deviation is within 10%, and the biotin interference phenomenon disappears. When the concentration was increased to 20ug/ml (numbers 7 and 8 in Table 1), the signal dropped within 10% of the deviation. When the concentration is not changed by 20ug/mL and the particle size and the aperture are increased, the signal falls to a certain extent, and the falling amplitude is 20-40%.

And (4) experimental conclusion:

when the anti-interference agent contained in the kit is microspheres filled with SA (streptavidin) and has the particle size of 100nm, the pore diameter of 10nm and the concentration of 10-20ug/mL, the anti-biotin interference capability of the kit is strongest. When the aperture of the added anti-interference agent is smaller and is 2nm, the kit has no anti-biotin interference capability. When the added anti-interference agent has a particle size of more than 100nm and a pore size of 10nm, the anti-biotin interference capability of the kit is reduced when the particle size and the pore size are continuously increased.

Example 10: the invention relates to an effect evaluation two experimental steps of a chemiluminescence immunoassay kit for anti-biotin interference, which comprises the following steps:

2. A40 ug/mL solution of beads was prepared, and different concentrations of the anti-interference agent prepared in examples 5 and 8 (diluted in PBS) were prepared, as shown in Table 4 (diluted in PBS) at 10ug/mL and 20 ug/mL.

4. Adding 25uL of sample solution, sequentially adding 25uL of reagent I and reagent II in the T3 kit, manually adding 25uL of sample solution, 25uL of reagent I and 25uL of reagent II according to a reaction mode, and adding 25uL of anti-interference agent solution prepared in the step 2 according to the following table, wherein the anti-interference agent is not added under the conditions 1 and 2.

6. Add 175ul of photosensing bead solution by hand.

8. Exciting the sample to be tested by using energy and reading the generated luminescent signal. See tables 5 and 6 for reading results.

TABLE 4

TABLE 5 TABLE 6

And (3) data analysis:

compared with serial numbers 3 and 5 in table 4, the anti-biotin interference ability of the anti-interference agent prepared by the physical adsorption method is strong, the luminescent signal drops by about 10%, and the luminescent signal of the anti-interference agent prepared by the covalent coupling method drops by about 50%. In comparison with serial numbers 4 and 6 in table 4, the anti-biotin interference ability of the anti-interference agent prepared by physical adsorption is better than that of the anti-interference agent prepared by covalent coupling.

And (4) experimental conclusion:

the chemiluminescence immunoassay kit comprising the anti-interference agent prepared by a physical adsorption mode has better anti-biotin interference capability than the chemiluminescence immunoassay kit comprising the anti-interference agent prepared by a covalent coupling mode for the same particle size, pore diameter, concentration and specific surface area.

Example 11: free thyroxine (T4) magnetic particle chemiluminescence immunoassay kit and preparation method thereof

Components of kit

1) A suspension of streptavidin-coated magnetic particles,

2) an alkaline phosphatase-labeled thyroxine derivative,

3) a biotin-labeled thyroxine antibody which is capable of binding to a target,

4) the dilution is tested and the concentration of the diluent,

5) a calibration product of thyroxine, which is prepared by mixing thyroxine and thyroxine with water,

6) the quality control of the thyroid gland hormone is realized,

7) an anti-interference agent.

Preparation of kit

(1) The preparation method of the thyroxine derivative marked by alkaline phosphatase comprises the following steps: adding alkaline phosphatase into sodium carbonate buffer solution (pH8.0), adding thyroxine derivative (T4-NHS), reacting at 4-37 deg.C for 0.5-24 hr, purifying enzyme-labeled antibody with protein affinity column (GE company) to obtain thyroxine enzyme conjugate, and diluting the thyroxine enzyme conjugate in enzyme-labeled buffer solution at a ratio of 1:400-1:2000, preferably 1: 1000.

(2) The preparation method of the biotin-labeled thyroxine antibody comprises the following steps: adding a thyroxine antibody (mouse, monoclonal) into a sodium carbonate buffer solution (pH8.0), adding a biotin derivative, reacting at 4-37 ℃ for 0.5-24 hours, purifying a biotin-labeled antibody by using a ProteinG affinity column (GE company) to obtain a thyroxine conjugate, and diluting the thyroxine biotin into the biotin-labeled buffer solution, wherein the dilution ratio of the thyroxine biotin to the biotin-labeled buffer solution is 1: 200-1: 1000, and the preferable dilution ratio is 1: 500.

(3) The preparation method of the thyroxine calibrator comprises the following steps: the thyroxine purified product was diluted to working concentrations of 0, 8.00, 15.00, 30.00, 60.00, 100.00pmol/L with calibrator buffer, respectively.

(4) The preparation method of the thyroxine quality control product comprises the following steps: the thyroxine pure product was diluted to working concentration with quality control buffer, 15.00, 60.00pmol/L respectively.

(5) Assembling: and (3) assembling the thyroxine derivative marked by the alkaline phosphatase, the thyroxine antibody marked by the biotin, the thyroxine calibrator and the thyroxine quality control product into a box, and storing at the temperature of 2-8 ℃.

Example 12: effect evaluation of free thyroxine (T4) magnetic particle chemiluminescence immunoassay kit

Reagent kit

(1) The kit described in example 11

(2) Comparison kit: the kit is the same as the kit described in example 11 except that the anti-interference agent is not contained.

Second, evaluation method

(1) A concentrated solution of T4 was added to the serum of degerming serum to prepare a solution of T4 at concentrations of 1nmol/L and 2 nmol/L. Biotin was added to the above-mentioned T4 solution to prepare sample solutions having biotin concentrations of 0 and 128ng/ml, respectively.

(2) Sample loading and incubation processes: sucking 25uL of free thyroxine calibrator, quality control product or sample solution, adding into a reaction tube, then adding 50uL of thyroxine derivative marked by alkaline phosphatase, 25uL of thyroxine antibody marked by biotin and 25uL (10ug/mL) of anti-interference agent, and incubating at 7 ℃ for 10 minutes; then adding 25uL of streptavidin-coated magnetic particle suspension, and incubating for 10 minutes at 37 ℃;

(3) magnetic separation and cleaning process: placing the reaction tube after the incubation reaction on a magnetic separation frame, standing for 1 minute, and removing supernatant; adding 150uL of magnetic bead coating buffer solution for the first time, placing the mixture on a magnetic separation frame, standing for 1 minute, and removing supernatant; adding 150uL of magnetic bead coating buffer solution for the second time, placing the mixture on a magnetic separation frame, standing for 1 minute, and removing supernatant; adding 150uL of magnetic bead coating buffer solution for the third time, placing the mixture on a magnetic separation frame, standing for 1 minute, and removing supernatant;

(4) and (3) a light emitting process: Lumi-Phos 530 substrate (available from Lumigen, USA) 50uL was added, and after incubation at 37 ℃ in the dark for 5 minutes, the luminescence value was measured by an automated chemiluminescence apparatus. The results of the measurements are shown in tables 7 and 8. In the tables, conditions 1 and 2 used are control kits, which do not contain an anti-interference agent.

TABLE 7 TABLE 8

From the above results, the effect of the kit containing the anti-interference agent is obviously better than that of the kit containing no anti-interference agent.

It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not constitute any limitation to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.

Claims

1. An anti-biotin interference chemiluminescent immunoassay kit comprising:

c) a chemiluminescent reagent.

2. The kit of claim 1, wherein the anti-interference agent is capable of recognizing both free biotin molecules and biotin conjugates.

3. The kit of claim 1 or 2, wherein the anti-interference agent is capable of selectively adsorbing free biotin molecules.

4. The kit of claim 3, wherein said free biotin molecule is capable of diffusing into said carrier and specifically binding to said active molecule therein.

5. The kit of any one of claims 1 to 4, wherein the anti-interference agent is capable of restricting the passage of a biological macromolecule larger in size than the active molecule into its carrier.

6. The kit according to any one of claims 1 to 5, wherein the anti-interference agent is capable of being uniformly distributed in a liquid phase reaction system.

7. The kit according to any one of claims 1 to 6, wherein the carrier has an internal surface area greater than its external surface area; preferably, the inner surface area of the carrier is more than 5 times, preferably more than 10 times, more preferably more than 20 times the outer surface area thereof; and/or the presence of a gas in the gas,

the particle size of the carrier is 15-300nm, preferably 30-250nm, and more preferably 50-200 nm; and/or the presence of a gas in the gas,

the specific surface area of the carrier is 200m²A ratio of one to more than g, preferably 400m²More preferably 600 m/g or more²More than g, most preferably 1000m²More than g; and/or the presence of a gas in the gas,

the support has a minimum porosity of greater than 40%, preferably greater than 50%, more preferably greater than 60%.

8. The kit of any one of claims 1 to 7, wherein the porous medium is selected from one or more of a porous metallic material, a porous non-metallic material, and a porous polymeric material.

9. The anti-kit according to any one of claims 1 to 8, characterized in that the support is a mesoporous microsphere, preferably an ordered mesoporous microsphere.

10. The kit according to claim 9, wherein the pore size of the mesoporous microsphere is 2-50nm, preferably 4-30nm, and more preferably 5-15 nm.

11. The kit according to claim 9 or 10, wherein the mesoporous microsphere is a cage-shaped hollow mesoporous microsphere.

12. The kit according to any one of claims 9 to 11, wherein the mesoporous microsphere is selected from Al₂O₃Mesoporous material and WO₃Mesoporous material and TiO₂Mesoporous material, ZrO₂At least one of the mesoporous material, the silicon-based mesoporous material and/or the mesoporous carbon material is preferably selected from silicon-based mesoporous materials.

13. The kit according to any one of claims 1 to 12, wherein the active molecule is selected from avidin and/or streptavidin.

14. The kit according to any one of claims 1 to 13, wherein the active molecule is packed in the carrier by physical adsorption.

15. The kit according to any one of claims 1 to 14, wherein the active molecule is filled in the carrier by contacting the carrier in a system comprising a buffer.

16. Kit according to claim 15, characterized in that the pH of the buffer containing system is 7 to 9, preferably 7.1 to 8.0, more preferably 7.2 to 7.8, further preferably 7.3-7.6.

17. The kit according to any one of claims 1 to 13, wherein the active molecule is packed in the carrier by direct or indirect chemical crosslinking.

18. The kit according to claim 17, wherein the carrier is modified with chemical groups on its inner surface, and the active molecule is filled in the carrier by covalent coupling with the chemical groups; wherein the chemical group is selected from one or more of carboxyl, aldehyde group, amino, sulfhydryl and hydroxyl.

19. The kit according to any one of claims 1 to 18, wherein the carrier has a biotin molecule attached to its inner surface, and the active molecule is filled in the carrier by specific binding to the biotin molecule.

20. The kit of any one of claims 1 to 19, wherein the anti-interference agent further comprises a buffer solution, preferably a PBS buffer solution.

21. The kit according to any one of claims 1 to 20, wherein the total concentration of the carrier and the active molecule filled in the carrier in the anti-interference agent is 5 to 50ug/mL, preferably 8 to 30ug/mL, more preferably 10 to 20 ug/mL.

22. The kit of any one of claims 1 to 21, wherein the anti-interference agent is prepared by a method comprising: step S1, contacting the carrier with the active molecule; preferably, the contacting is performed in a first buffer system.

23. The kit according to claim 22, wherein the preparation method of the anti-interference agent further comprises step S0: the carrier is washed with the second buffer system, and step S0 is performed before step S1.

24. The kit according to claim 22 or 23, wherein the preparation method of the anti-interference agent further comprises step S2: removing the active molecules not filled into the carrier, step S2 being performed after step S1; preferably, the active molecules not filled in the carrier are removed by adding a third buffer solution system to the carrier treated in step S1 and then performing solid-liquid separation.

25. The kit of any one of claims 1 to 24, wherein the kit further comprises a biotin conjugate comprising a substance that binds directly or indirectly to biotin and participates in an immune response.

26. The kit of claim 25, wherein the biotin conjugate is a biotin-binding antibody and/or a biotin-binding antigen.

27. The kit of any one of claims 1 to 26, wherein the kit is a homogeneous chemiluminescent immunoassay kit.

28. The kit of any one of claims 1 to 26, wherein the kit is a heterogeneous chemiluminescent immunoassay kit comprising a solid support.

29. The kit of claim 28, wherein the kit comprises the following components:

30. The kit of claim 28, wherein the kit comprises the following components:

31. The kit of any one of claims 28 to 30, wherein the solid support is selected from the group consisting of magnetic microspheres, plastic microparticles, microwell plates, glass, capillary tubes, and nylon; preferably selected from magnetic microspheres.

32. The kit of claim 31, wherein the magnetic microspheres have a particle size of 0.05 to 50 microns; preferably 0.1 to 40 microns; more preferably 5-20 microns.

33. The kit according to any one of claims 29 to 32, wherein the chemiluminescent reagent is selected from the group consisting of luminol and its derivatives, isoluminol and its derivatives, acridinium ester and its derivatives, adamantane, rare earth elements or ruthenium bipyridine complexes.

34. The kit of any one of claims 29 to 32, wherein the chemiluminescent reagent is a chemiluminescent catalyst selected from the group consisting of horseradish peroxidase and alkaline phosphatase.

35. The kit of any one of claims 29 to 34, wherein the first immune molecule is bound to one member of a specific binding pair member and the solid support is bound to the other member of the specific binding pair member; preferably, the first antibody or binding fragment thereof is bound to biotin and the solid support is bound to streptavidin.

36. The kit of any one of claims 29 to 35 wherein the second antibody or binding fragment thereof binds to one member of a specific binding pair member and the chemiluminescent reagent binds to the other member of the specific binding pair member; preferably, the second antibody or binding fragment thereof is bound to biotin and the chemiluminescent reagent is bound to streptavidin.

37. Use of a kit according to any one of claims 1 to 36 in the detection of the biotin-streptavidin system; preferably in thyroid function detection; further preferred is the use in the detection of triiodothyronine and/or tetraiodothyronine.