35 results about "Magnetic Bead Technology" patented technology

The invention discloses a single-chain DNA aptamer specifically recognizing streptomycin and application of the DNA aptamer, belonging to the field of biochemistry and molecular biology, analytical chemistry and combinatorial chemistry. The invention provides a method for preferably selecting the streptomycin aptamer by using an improved magnetic bead SELEX technology and four single-chain DNA aptamers with high appetency with the streptomycin and sequences of A1, A3, A6 and A12, and provides a high-specificity detection recognition element with the advantages of better stability, high sensitivity, low cost, and easy preparation, modification and mark for the detection of residue of the streptomycin, especially streptomycin in foods.

The invention discloses a capillary bioanalysis system, and an analytical method and applications thereof, and belongs to the field of medical equipment and biological detection technologies. The capillary bioanalysis system comprises a three-dimensional movement sample injecting platform, a temperature control-optical detection module, a magnetic field control module, a fluid control unit and a capillary array. The three-dimensional movement sample injecting platform and the fluid control unit are arranged on the two sides of the capillary array, and the capillary array is provided with the temperature control-optical detection module and the magnetic field control module. According to the capillary bioanalysis system, the droplet technology and the magnetic bead technology are combined, and bioanalysis processes such as loop-mediated isothermal amplification, fluorescence quantitative PCR analysis and immunochemiluminometry are integrated in capillaries. Advantages of the capillary bioanalysis system are that: volume is small, analysis speed is fast, detecting flux is large, and automation degree of operation is high. The capillary bioanalysis system is flexible in application, is suitable for analysis of single sample, batches of samples and on-site rapid detection, is capable of reducing acquisition cost and operation cost of equipment significantly, and possesses excellent economic benefits.

The invention discloses a microfluidic chip detection method based on magnetic bead technology. The method includes the steps of: 1, fluorescence labeling; 2, magnetic bead labeling; 3, coating and drying of a blocking solution; 4, immobilization of immunomagnetic beads; 5, immobilization of a fluorescence label; 6, microfluidic chip assembly; 7, sample adding preparation; 8, immunoreaction; 9, cleaning; 10, color development; and 11, data reading. The method provided by the invention selects highly sensitive time resolved fluorescent dye as the label for antibody labeling on magnetic beads and a fluorescent substance respectively, and utilizes the immunoreaction of the antibody pair for analysis and detection, and the performance of the prepared reagent can reach the level of equivalent chemiluminescent reagents. At the same time, the reagents adopt homogeneous liquid reaction to realize control of liquid flow. Ultrasonic mixing is adopted in the microfluidic chip chamber to avoid single-threaded chromatography flow reaction, therefore the reaction is fuller, and the reaction efficiency is higher.

The invention provides a micro-fluidic chip detection method based on a magnetic bead technology and a reagent freeze-drying technology and a micro-fluidic chip for realizing the method. According tothe method, on the basis of a microfluidic technology, mixing of a sample and a reagent, a flow mixing capture reaction, magnetic separation, cleaning, detection and the like are integrated on a chip,and all reagent components required by the reaction are integrated on the chip, so that the operation of a client is simple and convenient, and the detection can be completed anytime and anywhere. Aclosed micro-channel for a sample to flow is formed in the micro-fluidic chip, and the micro-channel comprises a mixing bin, a reaction bin, a delay channel, a capture bin and a waste liquid bin whichare sequentially communicated.

The invention provides a method for rapid detection of Listeria monocytogenes through combined nanometer immunomagnetic bead technology-colloidal gold chromatography. The method comprises the following steps: labeling a monoclonal antibody 1B12 by using a streptavidin-biotin mediated and coupled nanometer magnetic bead so as to prepare an immunomagnetic bead wherein the monoclonal antibody 1B12 has an accession number of CGMCC No. 10312 and is prepared and screened by using hybridoma technique; labeling another matching monoclonal antibody 3B10 with an accession number of CGMCC No. 10311 by using colloidal gold so as to obtain a labeled antibody, respectively using polyvalent antiserum and goat anti-mouse IgG as a detection line T and a quality control line C and constructing a colloidal gold immunochromatographic test strip from a conjugation pad of the colloidal gold-labeled antibody, a chromatographic membrane of the detection line T and the quality control line C and a water absorption pad; and in detection of a sample, subjecting the immunomagnetic bead and bacteria in the sample to specific capture and enrichment, then pouring an enrichment liquid onto a sample pad of the test strip and judging and reading chromogenic strips visible to naked eyes formed at the detection line T and the quality control line C according to the color of colloidal gold so as to realize rapid semi-quantitative detection of Listeria monocytogenes.

The invention discloses a method for extracting a microRNA precursor cDNA from a cDNA library synthesized from small RNA, which comprises the following steps of: carrying out the PCR amplification on the cDNA; carrying out the PCR amplification on the obtained cDNA fragments by using a primer with the 5' end with biotin labels, carrying out degeneration on the cDNA double strands obtained by amplification, and carrying out the cDNA double-strain separation by using a magnetic bead technology; renaturing the cDNA single strands obtained by separation to form single-strain cDNA with different secondary structures and respectively recovering, carrying a PCR reaction to form double strands; and carrying out enzyme digestion on PCR fragments by restriction enzymes, and cloning and sequencing. The invention can effectively enhance the efficiency of cloning and sequencing miRNA.

The invention discloses a method and an apparatus for detecting membrane damage based on an electrochemistry and magnetic bead technology. According to the apparatus and the method, a horizontal segment at the exactly middle of a clear-liquid outlet pipe is provided with a magnetic-bead detection device tightly connected with the clear-liquid outlet pipe; a positive electrode sheet and a negative electrode sheet are horizontally arranged side by side along the radial direction at the middle part in a magnetic-bead detection pipe and are immersed in a clear liquid; the lower segments of two adjacent but contactless metal electrodes both stretch into the clear liquid in the magnetic-bead detection pipe, and the upper segments both stretch out of the magnetic-bead detection pipe and are both winded by a coil; the tops of the two metal electrodes are both connected with an MCU main control unit via an MCU sampling interface; the resistance R0 of the clear liquid is calculated out according to the voltage and the current; and magnetic beads with the diameter larger than the membrane aperture are added into the original liquid, the voltage between the two metal electrodes is acquired and the resistance R at the current moment is calculated out, the resistance R and the resistance R0 are compared, and the damage degree of a filtration membrane is characterized through variation of the resistance of the clear liquid. The detection sensitivity is high, and the membrane is not destroyed.

The invention discloses a kit for extracting fungal/bacterial genomic DNA based on a magnetic bead technology and a method thereof, and belongs to the field of molecular biology. The kit comprises five components: a lysate, chloroform, magnetic beads, a magnetic bead rinsing liquid and a DNA eluant. The genomic DNA extraction includes the main steps of cracking a sample, carrying out magnetic beadadsorption and rinsing to obtain the genomic DNA. The operation method applying the kit is simple in steps, the extraction efficiency of the genomic DNA in fungi/bacteria can be greatly improved, andthe extracted DNA product has a clear and complete electrophoresis strip after PCR amplification and has good reproducibility. In addition, reagents required by the kit are conventional reagents, thecost is low, and the kit is suitable for high-flux experiments.

The invention discloses a report magnetic bead. The report magnetic bead comprises a magnetic bead, nucleotide and an enzyme with high catalytic activity which are linked. The invention further discloses a signal amplification magnetic bead technical system for nucleic acid detection based on the CRISPR technology, and a construction method and application of the report magnetic bead. By introducing the report magnetic bead, the sensitivity of the signal amplification magnetic bead technology system is improved from the aM (1000-10000 copies/mL) concentration level to the zM (1-10 copies/mL) concentration level.

A ssDNA aptamer for specifically identifying metronidazole and an application thereof belongs to the fields of biochemistry, molecular biology, analytical chemistry and combinatorial chemistry. In thepresent invention, a ssDNA initial library containing 35 random nucleotides is amplified by PCR through a magnetic beads-SELEX technology, and then immobilized on magnetic beads modified with streptavidin, added with metronidazole to separate ssDNAs with affinity by competition, and amplified for next screening. After ten rounds of screening and clone sequencing, 39 metronidazole aptamer sequences are obtained. After further affinity evaluation, four sequences with higher affinity including ap2, ap19, ap21, and ap32 are selected, wherein, the ap32 is selected as an optimal metronidazole aptamer due to the advantages of high affinity, high specificity and stable structure. The invention provides an identification element with excellent performance for metronidazole detection.

The invention relates to the making of agent for BFB bacteria of melons. It comprises the making of BFB immune antibody and BFB immune magnetic pearl, selecting non-solutble inertia as the solid carrier to exchange base chain with the ions to form ion exchange solid carrier with large quantity of exchangeable negative ion, activating the ion exchange solid carrier with the BFB immune antibody to get the BFB immune magnetic pearl. It uses the immune theory to couple the antibody with the inertia organic molecules, to establish the BFB quick inspection, quick, convenient, high in sensitivity, fine in special feature, improved in feature and sensitivity.

The invention provides a nucleic acid aptamer of a protein, which is a nucleic acid aptamer specifically combined with an NTRK1 protein. Preferably, the sequence of the nucleic acid aptamer comprises at least one of SEQ ID No. 1 and SEQ ID No. 2. The nucleic acid aptamer or its truncated nucleic acid aptamer and derivative of the nucleic acid aptamer provided by the invention can be highly specifically combined with NTRK1 protein, which is a novel targeting small molecule, and has the advantages of small molecular weight, high sensitivity, good stability, easy synthesis and modification and the like compared with an antibody. According to the invention, a first nucleic acid aptamer capable of being combined with the NTRK1 protein is screened out through a magnetic bead SELEX technology, and a novel potential targeting drug is provided for treatment of human chronic pain.

The invention provides a nucleic acid aptamer for specifically combining bovine pregnancy-related glycoprotein 4. The sequence of the nucleic acid aptamer comprises any one of SEQ ID No. 1 sequences.The nucleic acid aptamer provided by the invention can also be various similar sequences with higher homology or derivatives obtained from the sequences provided by the invention. The invention also provides an application of the aptamer. The nucleic acid aptamer disclosed by the invention is obtained by screening through a magnetic bead-SELEX technology; the aptamer can be combined with bPAG4 target protein, can also be selectively combined with bPAG4 like protein, is not specifically combined with other proteins, can be used for capturing the bPAG4 protein from a complex system, and is suitable for detection, separation and purification of the bPAG4 protein and quick diagnosis of bovine early pregnancy.

The invention provides a sheep pregnancy-related glycoprotein (ovPAG) aptamer. The sequence of the aptamer is shown as SEQ ID No. 1, and the aptamer can also be various similar sequences with relatively high homology or derivatives obtained from the sequences. The invention also provides application of the aptamer. The aptamer is obtained by screening through a magnetic bead-SELEX technology, hashigh affinity with sheep PAG protein, and can be used for separation, enrichment and detection of the PAG protein and rapid diagnosis of early pregnancy of livestock.

The invention discloses a Salmonella fluorescence quantitative determination immunochromatography kit which includes a test paper strip, immunomagnetic beads and a fluorescent labeling solution, the test paper strip is prepared by sequential lapped paste of a sample pad, a nitrocellulose coated film and absorbent paper on a polyethylene plastic bottom plate;a testing area of the nitrocellulose coated film is coated with Salmonella monoclonal antibody or polyclonal antibody, a quality control area is coated with anti-rabbit IgG antibody; the immunomagnetic bead surface is coupled with the Salmonella monoclonal antibody; and the fluorescent labeling solution contains fluorescent latex-marked Salmonella monoclonal antibody or polyclonal antibody and fluorescent latex-marked anti-rabbit IgG antibody. The Salmonella fluorescence quantitative determination immunochromatography kit combines magnetic bead technology and immunochromatographic fluorescence quantitative detection technology, after enrichment and concentration of Salmonella in a sample for detection by use of the immunomagnetic beads, quantitative determination is performed, and compared with a simple pure fluorescence quantitative chromatography detection kit, the Salmonella fluorescence quantitative determination immunochromatography kit greatly improves the detection efficiency.

The invention relates to the field of ophthalmology, in particular to a nucleic acid aptamer specifically binding to lipocalin-1 (LCN 1), and an application of the nucleic acid aptamer. A set of high-affinity nucleic acid aptamers specifically binding to LCN 1 are obtained through screening with the magnetic bead SELEX technology, and the performance of the nucleic acid aptamer is further improvedthrough optimization strategies such as truncation and construction of a highly stable mini-hairpin structure. The nucleic acid aptamer of the invention has broad application prospects, can be used for the capture of LCN 1 in clinical samples, the detection of LCN 1 in vivo and in vitro, the development of LCN 1 therapeutic drugs in eye diseases, the construction of targeted drug delivery systems, and the like, and provides an effective tool for the development of LCN 1-related detection technologies, the development of clinical diagnostic methods and the development of nucleic acid drugs.

The invention belongs to the technical field of forensic medicine, and relates to a method for separating cells by immunomagnetic beads, in particular to a method for separating male individual spermcells from seminal fluid vaginal fluid mixed spots by utilizing an immunomagnetic beads technology. The method comprises the following steps: step 1, mixing male seminal fluid and female vaginal fluidaccording to the principle of informed consent; step 2, coupling the sperms by using a biotin labeled ACRBP antibody, and enriching and collecting sperm cells of a male individual by using avidin coupled magnetic beads and an external magnetic field. and step 3, carrying out PCR amplification and capillary electrophoresis so as to perform genotyping on the STR locus. The method provided by the invention can effectively determine the source of the individual DNA in the male individual seminal stain from the gene level, greatly simplify the step of identifying the tissue source of the body fluid or its spots at the criminal investigation scene, and can provide an accurate scientific basis for defining case properties, determining criminal suspects, convicting and sentencing.