139 results about "Biotin binding" patented technology

Methods of reversal of the binding between a biotin compound and a biotin-binding compound are disclosed. A method of reversibly releasing a biotinylated moiety from a streptavidin (or avidin) coated support is shown as an example. The strong interaction between streptavidin or avidin-biotin is made much weaker by using a combination of modified streptavidin or avidin and modified biotin like desthiobiotin or a derivative thereof like DSB-X Biotin. A protein, such as an antibody may be biotinylated with the modified biotin. When this protein is isolated by binding the modified biotin to the modified streptavidin or avidin bound to an solid surface, it may be released under very gently and very rapid conditions by addition of free biotin. In contrast to proteins obtained by the prior art release methods the protein obtained using the previously available release methods, the proteins obtained using the methods disclosed herein will maintain their native conformation. Uses of the methods in various procedures including cell detachment procedures and techniques of detection, identification, determination, purification, separation and / or isolation of target proteins or nucleic acid molecules are also described.

Methods of preparing targeting ligand bound avidin-lipid vesicles for use in preparing a targeted, therapeutic liposome composition are disclosed. Each vesicle comprises an avidin molecule coupled to the polymer-conjugated biotin which retains multiple free site biotin-binding sites such that the vesicle may be used to further couple a biotinylated-targeting ligand.

Streptavidin-metallothionein chimeric proteins with biological recognition specificity in which the streptavidin moiety provides high affinity biotin binding and the metallothionein moiety provides a high affinity metal binding. The binding affinity of the streptavidin-metallothionein chimeric protein both for biotin and heavy metal ions allows specific incorporation into, conjugation with, or labelling of any biological material containing biotin with various heavy metal ions.

Provided herein are novel irreversible sialidase inhibitors. These compounds can be conjugated with a detectable tagging moiety such as azide-annexed biotin via CuAAC for isolation and identification of sialidases. The provided compounds and the corresponding detectable conjugates are useful for detecting sialidase-containing pathogens and imaging in situ sialidase activities under physiological conditions.

The invention discloses a method for detecting a surviving gene based on a graphene-gold composite material electrochemical DNA (Deoxyribose Nucleic Acid) biosensor. The method comprises the following steps: a specific probe is designed according to a gene segment to be detected; a capture probe is self-assembled on the surface of G-3DAu / GCE through a gold-sulfur bond; the capture probe and a signal probe with the tail end marked by biotin are respectively combined with a target DNA to form a 'sandwich' model in the presence of the target DNA; a horse radish peroxidase marked by avidin can be combined with the biotin marked by the signal probe, so that the HRP (Horse Radish Peroxidase) can be fixed on the surface of an electrode; the electrode is placed in a base solution of 3, 3', 5, 5'-tetramethyl benzidine (TMB) and H2O2, and the H2O2 can oxidize TMB to generate a bidiazotizedbenzidine material under the catalyzing of the HRP, so that an electrochemical signal is generated. The method has the advantages of being simple, quick and green in preparation process, and high in selectivity and sensitivity.

The invention relates to a colloidal gold immunochromatography test strip used for testing an H1N1 influenza antigen and a method for testing the H1N1 influenza antigen. The test strip comprises a base plate, a sample pad, a conjugate pad, a pyroxylin film and an absorbent paper, wherein the sample pad, the conjugate pad, the pyroxylin film and the absorbent paper are lapped and adhered on the base plate sequentially; the conjugate pad is a combination of a gold-label-biotin conjugate pad and a streptavidin-gold-antibody conjugate pad; according to the method for testing the H1N1 influenza antigen, a sample to be tested is dropwise added on the test strip; if a red band is displayed at a testing line (1), the sample to be tested contains the H1N1 influenza antigen. According to the advantages, the test strip provided by the invention is cheap in price, fast, simple, convenient, and greatly suitable for on-site testing; moreover, the test strip can meet the requirement of higher testing sensitivity, and has an important clinical diagnostic significance.

Magnetic particles having porous surfaces are obtained by forming a polymer part (B) soluble in an organic solvent (S) and a polymer part (C) insoluble in the organic solvent (S) on surfaces of magnetic matrix particles (A) and causing the polymer part (B) to come into contact with the organic solvent (S).

The invention discloses a non-diagnostic method for detecting a suspension chip of PCR products. The chip mainly comprises coded microspheres, a biotinylated primer, a capture probe, and streptavidin-biotin-phycoerythrin, and the method comprises the following steps that: the capture probe is coupled with corresponding microsphere of each size respectively, a red laser excites classified fluorescent lights on aspherical substrate, and the types are determined according to different colors of the spherical substrate, wherein the biotinylated primer shows the a primer needs biotinylation labeling during PCR; the microspheres coupled with the probe can be specifically combined with a PCR product labeled by an amplified biotin; and the streptavidin-biotin-phycoerythrin is combined with a biotin on the PCR product captured on the microspheres, a green laser excites the phycoerythrin, and the number of the reported fluorescent molecules combined on the spherical substrate is measured and is used for indirectly determining the content of the PCR product combined on the spherical substrate.

The invention relates to a method for sorting target cells by using avidin / streptavidin magnetic composite particles. In the method, a biotin-labeled monoclonal antibody is added into an experimental system, magnetic particles are bonded with the biotin-labeled monoclonal antibody through avidin / streptavidin, the monoclonal antibody is specifically bonded with corresponding antigen on the surfaceof the cells to make the cells captured by the magnetic particles so as to purify and separate the cells. Because the biotin-avidin and biotin-streptavidin have the characteristics of high system specificity, high stability, wide application range and low experiment cost, the obtained avidin / streptavidin magnetic composite particles have high biotin bonding property; and the labeled amount is improved in the measurement technique, and biomolecules are difficult to denature or inactivate, so that the cell sorting specificity is further improved. The high-purity target cells can be sorted by specifically bonding the biotin with the avidin or streptavidin; and the method has the advantages of no need of expensive instrument, simple operation and time saving.

The invention relates, in part, to monovalent streptavidin compositions. The invention also relates to methods of preparing and using monovalent streptavidin compositions. In some aspects of the invention, the compositions are monovalent streptavidin with a single femtomolar biotin-binding site.

The invention discloses a method for detecting a system for quickly screening a fever pathogen, and mainly relates to detection of a tuberculosis antibody, a flu antibody, a bird flu antibody, a plague antibody and an SARS antibody in blood serum. The chip mainly comprises coding microspheres, a coating antigen, a detection antibody, a biotinylated antibody and a streptavidin-phycoerythrin. The method comprises the following steps that: the coating antigen and the coding microshperes are coupled; the detection antibody is respectively coupled with the corresponding microspheres in separate specificity; the red laser excites the classified fluorescence on the spherical substrate; the type is determined according to different colors of the spherical substrates, wherein the biotinylated antibody is combined with the detection antibody; and the streptavidin-phycoerythrin is combined with the biotin of the detection antibody captured by the microshperes; the green laser excites the phycoerythrin, the number of report fluorescence molecules combined on the spherical substrate is measured, and the number is used for indirectly determining the content of the detection antibody combined onthe spherical substrate, so that whether the pathogen infection exists is determined, and the aim of quickly screening the fever pathogen is achieved.

The present invention provides a method of assaying for kinase activity, comprising contacting a fluorescently labeled phosphorylatable peptide substrate with an ATP analog in the presence of a kinase enzyme to yield a first product; contacting the first product with a reactant that comprises a biotin derivative to yield a second product; contacting the second product with a biotin-binding protein; and detecting a difference in a fluorescence polarization level from the second product as compared to a fluorescence polarization of the peptide substrate.

The invention belongs to the field of pharmaceutical preparations, and provides a pharmaceutical albumin nanoparticle, a preparation method and application of the nanoparticle to tumor targeting therapy. The nanoparticle is made from two types of proteins, namely avidin and albumin, encapsulating slightly-soluble antitumor drugs. The electrostatic interaction exists between avidin and albumin, and avidin in the nanoparticle can be combined with biotin. Avidin can target the nanoparticle encapsulating the drugs on a biotin enrichment part. Before the application of the nanoparticle, a biotinylated antibody is used for pre-targeting on a tumor part, and can improve the distribution of a nanoparticle preparation in the tumor part. The biotinylated antibody and the nanoparticle preparation are combined for therapy, thereby playing better antitumor effect than the effect played by the combination of a monoclonal antibody and an albumin nanoparticle without avidin.

Provided are streptavidin-bonded magnetic particles having a high biotin binding capability, and a manufacturing method for the same. Streptavidin-bonded magnetic particles are characterized by having a structure in which streptavidins are cross-linked on magnetic particles. A manufacturing method for streptavidin-bonded magnetic particles including the following steps. (1) A step for preparing a suspension containing magnetic particles having amino groups on the surface thereof; and (2) a step for adding glutaraldehyde to the suspension prepared in step (1), in the presence of streptavidin, and reacting the magnetic particles with the streptavidin and glutaraldehyde. These streptavidin-bonded magnetic particles, and streptavidin-bonded magnetic particles manufactured by means of this manufacturing method can be used in clinical diagnosis.

The present invention relates to gene chip detection method and is one using no radioactive label and no fluorescent label. The detection method includes the following steps: extracting the tested target gene in sample, labeling the gene with digoxin or biotin to obtain labeled DNA or RNA for hybridization with the gene chip; making nano gold labeled digoxin antibody to combined with digoxin or nano gold labeled avidin to combine with biotin; dyeing the hybridized gene chip with silver dyeing reagent; direct microscope oservation, CCD record of signal or scanning detection with common opticalscanning instrument to obtain corresponding crossing result; and further analysis by using relative software.

Provided herein are self-assembling pharmaceutical compositions comprising a heat shock protein fused to a biotin-binding protein, wherein the biotin-binding protein is non-covalently bound to four biotinylated components, and further wherein at least two of the four biotinylated components are not identical.

The present invention provides a method of binding a protein to a carrier in such a way that the protein is not impaired in its function but can be allowed to act more efficiently than when it is bound directly.The method of the present invention for binding a protein to a carrier comprises:preparing a biotin-bound carrier;preparing a fusion protein having the protein bound to a tamavidin; andbinding the protein to the carrier via tamavidin-biotin bonds.

The present invention provides a method of binding a protein to a carrier in such a way that the protein is not impaired in its function but can be allowed to act more efficiently than when it is bound directly.The method of the present invention for binding a protein to a carrier comprises:preparing a biotin-bound carrier;preparing a fusion protein having the protein bound to a tamavidin; andbinding the protein to the carrier via tamavidin-biotin bonds.

The invention discloses a nano-pore electrical sensor used for enzyme reaction detection. The nano-pore electrical sensor used for enzyme reaction detection comprises a substrate layer, an insulationlayer, and a thin film which are overlapped from bottom to top successively; the center of the thin film is provided with a nanopore; the internal part of the nanopore is provided with a DNA probe through chemical modification, and a DNA tetrahedral structure capable of realizing complementary hybridization with the DNA probe; the DNA tetrahedral structure is combined with horseradish peroxidase labelled streptavidin through biotin, so that single horseradish peroxidase is immobilized in the nanopore; a reaction substrate is added to detect oxidation reaction product translocation events and realize real-time monitoring on enzyme reaction. The nano-pore electrical sensor used for enzyme reaction detection is capable of solving problems in the prior art that in enzyme reaction detection large amounts of reagent and plenty of time are consumed, and the enzyme immobilization method of enzyme in the nanopore is capable of providing research ideas for study on the molecular dynamics of thesingle enzyme in the nanopore.

The present invention relates to diagnosis kit for Mycobacterium species identification and drug-resistance detection and manufacturing method thereof, which can discriminate a Mycobacterium Tuberculosis rpoB gene point mutation relating to the Mycobacterium species identification and drug-resistance swiftly, exactly and in large quantities using an oligonucleotide chip. The diagnosis kit for Mycobacterium species identification and drug-resistance detection in accordance with the present invention consists of an oligonucleotide chip including a Mycobacterium tuberculosis complex probe, a Mycobacterium species identification probe and a drug-resistance detection probe of a Mycobacterium tuberculosis rpoB gene, and a fluorescent material containing a biotin-binding protein so as to detect hybridization of amplified products of a specimen marked as biotine and the corresponding probe.

In one embodiment is provided a new class of biotin recognition sensors which comprise a biotin recognition compound (containing a biotin binding moiety), a fluorescent donor moiety, and an acceptor moiety. These compounds are useful for detecting biotin in a sample or on a carrier molecule. In addition to compounds, the invention also provides methods and kits for detecting the presence of biotin in a sample or on a carrier molecule.

Streptavidin-metallothionein chimeric proteins with biological recognition specificity in which the streptavidin moiety provides high affinity biotin binding and the metallothionein moiety provides a high affinity metal binding. The binding affinity of the streptavidin-metallothionein chimeric protein both for biotin and heavy metal ions allows specific incorporation into, conjugation with, or labelling of any biological material containing biotin with various heavy metal ions.

The present invention belongs to the field of fluorescent proteins in biotechnology, and particularly relates to a preparation method of a high fluorescence intensity recombinant phycobiliprotein concatermer. According to the preparation method, a streptavidin gene is linked to an allophycocyanin alpha subunit gene through a linker sequence; on the basis, one or a plurality of allophycocyanin alpha subunit genes are connected in series through linker sequences to form a fusion gene; and the fusion gene, a phycobiliprotein lyase gent and a phycoerythrobilin biosynthetic enzyme gene co-express in Escherichia coli to obtain the recombinant allophycocyanin concatermer with characteristics of biotin binding ability and high fluorescence intensity. According to the present invention, tn the immunofluorescence assay, the recombinant phycobiliprotein concatermer can achieve the strong fluorescent signal compared to the recombinant phycobiliprotein monomer; and the prepared recombinant phycobiliprotein concatermer can be adopted as the fluorescent marker for immunofluorescence detection in the field of biology and biomedicine.

The invention provides methods for highly-specific detection of hybridization of single stranded nucleic acids. The invention also provides methods for target identification which rely on this highly-specific hybridization detection. Targets suitable for detection include, but are not limited to, nucleic acid biomarkers. The methods of the invention can employ an on-chip, DNA polymerase-dependent labeling scheme termed primer extension (PEX) to couple biotinylated deoxyribonucleotide triphosphate (dNTP) molecules to nucleic acid hybrids bound to a solid substrate, allowing for subsequent recognition by biotin-binding-protein-labeled photoinitiators. Surface-initiated polymerization from these surface bound photoinitiators can lead to the formation of macroscale amounts of polymeric material, thereby amplifying the signal from the initial molecular recognition event.

The present invention provides a streptavidin-coupled magnetic particle with high biotin-binding capacity, and a manufacturing method thereof. The streptavidin-coupled magnetic particle has a structure in which streptavidins are cross-linked with each other on a magnetic particle. A method for manufacturing the streptavidin-coupled magnetic particle includes the steps of:(1) preparing a suspension containing magnetic particles having amino groups on their surface; and(2) reacting the magnetic particles with streptavidin and glutaraldehyde by adding glutaraldehyde in the presence of streptavidin to the suspension prepared in step (1).The streptavidin-coupled magnetic particle of the present invention, and the streptavidin-coupled magnetic particle manufactured by the manufacturing method of the present invention are useful in clinical diagnosis.

The invention discloses a stable 25-hydroxyvitamin D (25-OH VD) chemiluminescence immunoassay kit. The kit includes a reagent R1, a reagent R2, a reagent R3, a reagent R4 and a reagent R5. R1 is a buffer containing streptavidin magnetic particles. R2 is a buffer containing chemiluminescence marker-labeled 25-hydroxyvitamin D polyclonal antibodies and a protective agent. R3 is a buffer containing asmall molecule antigen derivative of biotin-bound vitamin and a protective agent. R4 and R5 are sample pretreatment reagents, and are used to dissociate 25-hydroxyvitamin D existing in a binding protein form in serum or plasma. The kit of the invention uses casein micelles as the protective agents to add the same in the reagent buffers, and is used to detect the content of the 25-hydroxyvitamin Din the serum or the plasma, effectively improves stability of the antigen derivative and accuracy of a testing result, solves the defect problems existing in the prior art, and facilitates storage and transportation of the reagents.

The invention relates to an EV71 (Enterovirus) virus detection method based on magnetic microsphere separation and chemiluminescent immunity imaging. The method mainly comprises the following steps of: coupling an EV71 virus rabbit anti polyclonal antibody with a magnetic microsphere; adding a sample to be detected and the magnetic microsphere to a micropore plate to ensure that the virus in the sample to be detected is bonded with a virus polyclonal antibody; then adding a biotinlated EV71 virus VP1 protein rabbit anti polyclonal antibody to ensure that the EV71 virus VP1 protein rabbit anti-polyclonal antibody is in specific reaction with the sample to be detected; adding SA-HRP (Streptavidin-Horseradish Peroxide) to be bonded with biotin so as to form a magnetic microsphere-polyclonal antibody-virus-polyclonal antibody-HRP compound finally; and adding a chemiluminescent substrate, and detecting chemiluminescent intensity. In the invention, the chemiluminescent intensity is in direct proportion to the concentration of the virus to be detected, and a linear relation between the chemiluminescent intensity and the concentration of the EV71 virus to be detected can be obtained. The EV71 virus detection method has the advantages of simplicity and convenience for operation, high sensitivity, strong specificity and the like, and can better meet the demand of clinical detection of the EV71 virus.

The invention discloses a construction method of an enzyme-reponsive multifunctional nano-coating. The construction method comprises the following steps: firstly, immobilizing avidin molecules to the surface of dopamine-coated stainless steel; then, on the basis of specific recognition and binding effects between avidin and biotin, immobilizing biotinylated heparin / PEI nanoparticles to the surface of a material, and further binding high-concentration avidin molecules to residual biotin on the surface of a nanoparticle coating, so that a novel biotin binding site is introduced; then, continuing to assemble biotinylated enzyme-responsive polypeptide to the surfaces of the nanoparticles on the basis of an interaction between the biotin and the avidin; and finally, by virtue of an EDC / NHS / MES coupling agent, immobilizing SDF-1[alpha] to an amino terminal of the polypeptide in a covalent mode, so that the multifunctional nano-coating, which has a matrix metalloproteinase 9 responsive characteristic, is constructed. According to the construction method provided by the invention, by constructing a multifunctional layer, which has anti-coagulating and endothelial regeneration inducing capacities, on a titanium surface, blood compatibility and a damaged endothelial repair capacity of the material can be obviously improved.

A method for detecting a cytokine in a biological fluid sample with a high sensitivity is provided. A time-resolved fluoroimmunoassay (TR-FIA) method including a step of forming on a solid phase a composite in which a cytokine is captured and which includes a fluorescent structural portion which has been complexed with a lanthanoid metal ion, and measuring fluorescence of the fluorescent structural portion. The composite is formed of a structure in which (a) a first antibody including a portion bound to a solid phase and a region bindable to a cytokine; (b) the cytokine; (c) a second antibody including a region bindable to the cytokine and a portion to which biotin is bound; (d) a conjugate including streptoavidin or avidin and a fluorescent structural portion capable of being complexed with a lanthanoid metal ion; and (e) the lanthanoid metal ion are bound. The fluorescent structural portion is represented by General Formula (I): R—Ar—C(═O)—CH2—C(═O)—CnF2n—X.