69 results about "Immunomagnetic separation" patented technology

The invention discloses a cell sorter micro-fluidic chip based on the immunomagnetic separation technology and application thereof in the aspect of enrichment of rare cells, belonging to the technicalfield of micro-fluidic chips. The micro-fluidic chip, improved on the basis of the existing Y-type micro-fluidic chip, comprises a substrate and a cover-slip, wherein a Y-shaped micro-channel, a sample cell (1) and a buffer cell (2) respectively located at two end points of the upper part of the Y-shaped micro-channel, and an effluent cell (3) located at the end point of the lower part of the Y-shaped micro-channel are arranged on the substrate; and an antigen / antibody immunological reaction chamber (4) located on the micro-channel between the cross point (5) of the Y-shaped micro-channel andthe effluent cell (3) is further arranged on the substrate, wherein the width of the antigen / antibody immunological reaction chamber (4) is 2 to 5 times that of the micro-channel. The chip of the invention can effectively and rapidly fix the magnetic beads, increase the sample size of cells, improve the analysis flux, reduce the dead volume of sample introduction and reduce the retention and cross infection.

Methods are provided for detecting, separating, isolating and quantifying contaminants in starting materials by separating the contaminant from the starting material using a bead coupled to an affinity moiety and quantum dot-labeling the contaminant. The contaminant is detected by the characteristic emission spectrum of the quantum dot. Also, competitive binding methods are provided wherein the starting material and a control material are contacted with a quantum dot coupled to an affinity moiety capable of binding the contaminant and a competitor complex. A decrease in the intensity of the characteristic emission spectrum of the quantum dot associated with the competitor complex from the starting material as compared to that of the control material is indicative of the presence of the contaminant in the starting material.

The invention is directed to a method for detecting low concentrations of bacteria in liquid solution that may or may not be complex liquid solutions. In one embodiment, immunomagnetic separation (IMS) is used to separate target bacterium that may be in a liquid mixture from other constituents in the mixture. A low concentration of a bacteriophage for the target bacteria is subsequently used to infect target bacterial cells that have been captured using the IMS technique. If at least a certain concentration of target bacterium are present, the bacteriophage will multiply to a point that is detectable. Matrix assisted laser desorption ionization / time-of-flight-mass spectrometry (MALDI / TOF-MS) is then used to produce a mass spectrum that is analyzed to determine if one or more proteins associated with the bacteriophage are present, thereby indirectly indicating that target bacterium were present in the liquid mixture.

The invention adopts double-function gold magnetic nanoparticles and provides a detection method which integrates an immunomagnetic bead capturing technology and an immunochromatography technology and is used for rapidly detecting salmonellas. Immunomagnetic separation and immunochromatography are organically integrated, the step of eluting the salmonellas from immunomagnetic beads is eliminated and the capture efficiency is improved; the step of spraying colloidal gold on a bonding mat is eliminated, the immunological reaction is more uniform and a variable coefficient is small in the quantitative detection; workload and probability of mixed bacterium pollution are reduced. The detection method adopts the basic thinking of exploring the mode of effectively combining the gold magnetic nanoparticles and an antibody, optimizing the conditions of enriching the salmonellas and carrying out rapid quantitative detection by using the immunochromatography technology as a vector and using the double antibodies sandwich as a detection principle.

The invention relates to a novel method of preparing agarose magnetic microspheres and application of the prepared agarose magnetic microspheres to separation and purification of an IgG antibody by utilization of an immunomagnetic separation technique. In specific, active amino is introduced to surfaces of the agarose magnetic microspheres, glutaraldehyde is adopted as a crosslinking arm to crosslink a ligand, and the ligand is staphylococcus aureus protein A capable of being specifically combined with the IgG antibody, thus preparing immunomagnetic microspheres capable of specifically adsorbing the IgG antibody. In addition, lysate of bacteria generating the IgG antibody by fermentation is separated and purified by utilization of a magnetic separation and purification device, the activity of the prepared antibody can reach 1.5*10<8> g IU / mg, the corresponding activity recovery rate is more than 90%, the purity of the antibody is almost 100% by purification analysis, and each index meets the national standards.

The invention applies difunctional nanogold particles and provides a listeria monocytogenes rapid detection method integrating an immunomagnetic bead capture technique and an immunochromatography technique. The immune magnetic separation and immunochromatography are organically integrated, the step of eluting the listeria monocytogenes from an immunomagnetic bead is eliminated, so the capture efficiency is improved; the step of spraying colloidal gold on a binding pad is eliminated, so that the immunological reaction is much evener, and the variable coefficient is small during quantitative determination; and the workload and the living contaminant rate are reduced. The basic train of thought of the detection method is exploring the effective combination method of the nanogold magnetic particles and an antibody, optimizing the condition of enriching the listeria monocytogenes on the nanogold magnetic particles and the antibody, and conducting rapid quantitative detection by using the immunochromatography technique as a carrier and a double-antibody sandwich as a detection principle.

The invention applies difunctional nanogold magnetic particles and provides an escherichia coli O157:H7 rapid detection method integrating an immunomagnetic bead capture technique and an immunochromatography technique. The immune magnetic separation and immunochromatography are organically integrated, the step of eluting the escherichia coli O157:H7 from an immunomagnetic bead is eliminated, as a result, the capture efficiency is improved; the step of spraying colloidal gold on a binding pad is eliminated, so that the immunological reaction is much evener, and the variable coefficient is small during quantitative determination; the workload and the living contaminant rate are reduced. The basic train of thought of the detection method is exploring the effective combination method of the nanogold magnetic particles and an antibody, optimizing the condition of enriching the escherichia coli O157:H7 on the nanogold magnetic particles and the antibody, and conducting rapid quantitative detection by taking the immunochromatography technique as a carrier and a double-antibody sandwich as a detection principle.

The invention provides a compound with an alpha-glucosaccharase inhibitory activity in a mulberry leaf. The preliminary screening from the mulberry leaf is carried out by immunomagnetic separation and liquid chromatography-mass spectrometry and a nuclear magnetic resonance method; and a separation or configuration target compound is prepared for verifying the alpha-glucosaccharase inhibitory activity, and thus the compound with the alpha-glucosaccharase inhibitory activity is obtained. Compared with a traditional method, no separation compound for preliminary screening is needed, so that the screening efficiency is remarkably increased, the screening time is shortened and the preparation and separation steps of the marked compound are reduced. In addition, the screening method disclosed by the invention has the characteristics of quickness, accuracy, favorable reproducibility and the like. The quick screening of the compound with the alpha-glucosaccharase inhibitory activity in a natural medicament or traditional Chinese mixture can be popularized. The compound with the alpha-glucosaccharase inhibitory activity, which is obtained by the method disclosed by the invention, can be applied to preparation of medicaments for resisting diabetes mellitus.

The invention discloses a method of detecting ochratoxin A in cereals by means of a nano antibody and immunomagnetic separation. The method includes the steps of: 1) combining anti-OTA nano antibody with nano immunomagnetic beads to prepare IMB, and enriching the OTA in the cereals by means of the IMB to prepare a pretreated sample; 2) with dot immunization method, immobilizing an OTA-OVA detection antigen on a PVDF film, wherein the immunomagnetic beads are subjected to an immune-reaction in the form of antibody marker, the OTA-OVA and the to-be-tested substance, OTA, are combined with the antibody competitively so as to determine whether the immunomagnetic beads are aggregated on the PVDF film or not, thereby obtaining a detection result. The method achieves simple and quick qualitative detection. An operator can read the result just by naked eyes without any analysis instrument. Furthermore, the method can be used for developing a novel quick and visible detection card for specially detecting the OTA in the cereals.

The invention provides a rapid detection method for mercury in a liquid biological sample based on magnetic separation and quantum dots (QDs) marking. The method comprises the steps: (1) preparing mercury-resistant monoclonal antibodies; (2) coupling the mercury-resistant monoclonal antibodies with magnetic nanobeads through covalent bonds to prepare mercury-resistant immunomagnetic nanobeadd; and (3) adding a difunctional chelating agent, bovine serum albumin (BSA) and triethylamine (TEA) into the liquid biological sample to incubate, then, adding the mercury-resistant immunomagnetic nanobeads to sufficiently mix, next, carrying out magnetic separation, and adding biotinylated BSA antibodies and streptavidinylated QDs into a sediment, and carrying out fluorescence detection by using a fluorescence microplate, wherein the sediment is obtained through magnetic separation. The invention also provides a rapid detection kit for mercury in a liquid biological sample.

The invention relates to a single base mutation detection method combining nucleic acid temporary hybridizing and magnetic separating. The method comprises the following steps: A, designing a capturing probe and a signal probe according to a target gene; B, preparing a magnetic sphere solution from a magnetic sphere coupled with the capturing probe, adding the signal probe to conduct nucleic acid hybridization with a to-be-detected sample; C, conducting magnetic separation after finishing the nucleic acid hybridization, and then re-suspending the magnetic sphere in a low-metal ion solution; D, conducting magnetic separation again, detecting an obtained liquid supernatant, judging whether single base mutation exists in the to-be-detected sample, wherein the capturing probe is completely complementary with a non-mutation part of the target gene; the signal probe is completely complementary with a mutant type gene of the target gene, and forms a single base mismatch with a wild type gene of the target gene. The detection method is fast, and can be used in low-abundance mutation detection.

The invention discloses a highly sensitive and decomposable quantum dot nanosphere probe and a preparation method thereof. Through a fulcrum-mediated strand displacement reaction, a DNA hairpin probe modified by three desulfated biotins is self-assembled into a Y-type DNA nanostructure; and the Y-type DNA structure and quantum dots coupled to streptavidin are self-assembled to form the quantum dot nanosphere probe. The prepared quantum dot nanosphere probe and an immunomagnetic separation technology are combined to be applied to quick detection of a target analyte. Because of a binding force between biotin and streptavidin stronger thana binding force of desulfurized biotin, the quantum dot nanosphere probe is decomposed, and thus quantum dots are released; the target analyte concentration is determined by detecting the fluorescence value of a quantum dot solution, and a shielding effect of immunomagnetic beads on the quantum dots is overcome. The method has high sensitivity and the detection limit of microorganisms is 1.37 cfu / mL. This method is good in specificity, and common other microorganisms do not affect the detection.

The invention relates to a quick detection method for food-borne pathogens based on immunomagnetic separation of Fe3O4 nano materials, belonging to the technical field of quick detection of food safety pathogens. Depending on an established quick screening method which can be used for pathogens in a food liquid sample, the invention prepares immunomagnetic beads from Fe3O4 nano materials, enriches target strains in a targeted manner, and indirectly detects whether the target pathogens are contained in the sample by separating the nano magnetic beads capturing the target bacteria, converting into iron ions through nitration reaction and inspecting the iron ions. The amount of the iron ions and the target bacteria show a linear relationship under certain conditions, and the target bacteria can be quantitatively detected in a certain range. The method can be used for the quick detection of harmful pathogens in a food sample, and thus can be used for quickly screening a large number of samples to be detected.

The invention discloses a nucleotide sequence analysis method based on a magnetic separation and high-fidelity polymerase correction function. The method comprises the following steps of: 1) fixing a sequencing primer digested by a nucleic acid resistant exonuclease on a magnetic medium and hybridizing the sequencing primer with a DNA sequence to be detected; 2) adding an extension reaction solution of which the component comprises a DNA polymerase which does not have the activity of the exonuclease, extending a marked deoxyribonucleotide monomer and a marked bideoxyribonucleotide monomer, and obtaining the type information and the number information of nucleotides by detecting a marked object signal; 3) adding an extension reaction solution of which the component comprises the DNA polymerase which has the activity of the exonuclease, removing the extended dideoxy nucleotide (ddNTP) in step 2) through the correction function of a high-fidelity polymerase, and substituting and extending the nucleotide monomer digested by the nucleic acid resistant exonuclease; and 4) performing magnetic separation and washing on the magnetic medium, and circulating the step 2), the step 3) and the step 4) until the nucleotide sequence information in the DNA to be detected is determined.

The invention belongs to the technical field of cell separation and analysis, and in particular relates to a trace cell capturing system based on a microfluidic and immune magnetic separation double policy. The system comprises a spiral microfluidic chip and a chip tray comprising a magnet. The microfluid chip comprises a sample inlet (11), a sheath liquid inlet (12), a spiral runner (13), a tracecell collecting outlet (14) and a waste liquor port (15). The spiral runner is composed of a single spiral channel, the inlet of the single spiral channel is formed near the center of a round spiralchannel and enters the spiral microfluidic channel through a semi-circular starting channel, and the runner tail end comprises two outlets which separately collect trace cells and waste liquor in thesample. The chip tray is used for fixing a chip and comprises a chip tray base (21), a chip groove (22), a chip fixing elastic sheet (23) and a magnet (25). The round magnet is fixed in the groove ofthe chip tray and corresponds to the center position of the spiral runner. The trace cell capturing system provided by the invention combines the single spiral microfluidic chip and immune magnetic separation for the first time and can form a double policy cell separation system by means of cell sizes, density and surface markers, so that the recovery rate of trace target cells in a complex sampleis improved truly.

The present invention relates to methods and systems for labeling, isolating, detecting, and / or enumerating a statistically significant number of biological cells, or other biological analytes of interest, present in a complex matrix sample. The isolation of a biological target of interest from a sample mixture is done by immunomagnetic separation. Upon introduction of the sample within an imaging chamber, the capture complex (biological target-magnetic capture agent) will be attracted by the magnetic field and will lay on the surface of the chamber in the focal plane of the imaging system.

The invention discloses a microbial detection method based on immunomagnetic separation and urease catalysis; target microorganisms are separated and enriched through immunomagnetic breads modified by biological recognition elements, and the concentration of the target microorganisms is improved; the salt ion concentration of a urea solution is changed by a urease catalytic reaction, so that a detection signal is effectively enlarged, and the detection sensitivity is substantially improved; moreover, the urease catalytic reaction belongs to a liquid-liquid phase reaction, the efficiency of the reaction mode is higher than that of a traditional solid-liquid phase reaction, the detection speed can be substantially improved, and a quantitative detection result of a small amount of microorganisms is obtained within 2 hours.

The present invention relates to methods and systems for labeling, isolating, detecting, and / or enumerating a statistically significant number of biological cells, or other biological analytes of interest, present in a complex matrix sample. The isolation of a biological target of interest from a sample mixture is done by immunomagnetic separation. Upon introduction of the sample within an imaging chamber, the capture complex (biological target-magnetic capture agent) will be attracted by the magnetic field and will lay on the surface of the chamber in the focal plane of the imaging system.

The invention relates to a method for enriching Cryptosporidium parvum oocysts and Giardia Lamblia sporocysts in water. The method comprises the following steps: adding an inorganic metal salt coagulant into a bulk water sample, stirring, coagulating, precipitating, collecting precipitate alumen ustum in a small-volume container, adding acidic solution into the small-volume container to dissolve the alumen ustum, centrifuging, removing supernate and thus, enriching the Cryptosporidium parvum oocysts and Giardia Lamblia sporocysts in water. In the invention, the problems of low Cryptosporidium parvum oocyst and Giardia Lamblia sporocyst enrichment rate, instability, high operation requirement and expensive filtering equipment and consumable items of the conventional method for enriching Cryptosporidium parvum oocysts and Giardia Lamblia sporocysts. The method does not need expensive apparatus and equipment and medicines and greatly reduce capital investment. The method is simple in operation, easy to master, time-saving and labor-saving, reduces cost of enrichment of Cryptosporidium parvum oocysts and Giardia Lamblia sporocysts in water, improves enrichment efficiency and is a novel method which clears the preliminary work for subsequent steps of immunomagnetic separation, immunofluorescence label microscope counting, polymerase chain reaction (PCR) qualitative detection, nano probe gene chip detection and Real-time PCR quantitative detection and the like.

The invention relates to a detection kit for detecting a tumor marker, which belongs to the detection field of analysis. An immune magnetic ball which is covalently coupled with a tumor marker antibody is used as a solid vector of the immune reaction, an immune magnetic separation technology is used for separating and gathering the target tumor markers, a catalytic signal of a marker enzyme is converted into metal nano particles deposited on the surface of a liquid crystal sensitive membrane to disturb liquid crystal molecules according to an enzymatic metallization signal conversion and amplification strategy, so that the visual detection of the target tumor marker can be realized. According to the method, the immune magnetic separation technology is combined with the enzymatic metallization and a liquid crystal biosensor to establish a liquid crystal immunoassay based on the immune magnetic separation, so that the problem that when the liquid biosensor is applied to the immunoassay,the sensitivity is low, and the interference resistance is low can be solved. The method has the characteristics of high sensitivity, simplicity in operation, no need of complicated instruments, visualized detection result and the like and can be directly used for detecting the tumor marker in a complicated sample.

The invention discloses a method for quickly detecting beta-hemolytic streptococcus in a textile product. The method is characterized in that two technologies of IMS (immunomagnetic separation) and RPA (recombinase ploymerase amplification) are combined, and the beta-hemolytic streptococcus in a sample is enriched by an immunomagnetic bead capturing technology; one set of specific primer and probeusing the RPA technology as the core technology is designed for the target gene with the specificity HtrA of the beta-hemolytic streptococcus, and the enriched beta-hemolytic streptococcus is detected by the RPA technology. The method has the advantages that the culture is not needed in the whole process; the time is shortened, the operation is quick, the efficiency is high, the specificity is good, the sensitivity is high, the anti-interference property is strong, the application range is broad, and the detection cost is low; the method is not only suitable for sanitation health and epidemicprevention departments and health and supervision departments, and but also suitable for the sanitation detection in enterprises and families.

The invention relates to a negative-phase enrichment method and kit for rare cells in blood based on microfluidics and immunomagnetic separation. The negative-phase enrichment method comprises the following steps: (1) subjecting a blood sample to centrifugation with a pre-treatment fluid so as to remove a part of impurities in blood; (2) subjecting the sample treated in the step (1) to lysis with a lysis solution, removing erythrocytes in blood and collecting residual cells; (3) adding magnetic particle-bonded leucocytes connected with corresponding antibodies into the residual cells and carrying out immunoreactions at room temperature; (4) subjecting the sample treated in the step (3) to separation with a separating medium to remove unbonded magnetic particles; and (5) carrying out separation by using an immunomagnetic particle capturing instrument and micro-fluidics and removing leucocytes so as to an enriched sample. The invention also provides the corresponding kit. According to the invention, erythrocytes are subjected lysis; and a plurality of technologies like immunomagnetic separation, density gradient centrifugation and micro-fluidics are optimally combined to rapidly remove leucocytes, and the removal rate of leucocytes reaches 99% or above.

The present invention relates to methods and systems for labeling, isolating, detecting, and / or enumerating a statistically significant number of biological cells, or other biological analytes of interest, present in a complex matrix sample. The isolation of a biological target of interest from a sample mixture is done by immunomagnetic separation. Upon introduction of the sample within an imaging chamber, the capture complex (biological target-magnetic capture agent) will be attracted by the magnetic field and will lay on the surface of the chamber in the focal plane of the imaging system.

The invention discloses a microbe concentration detection method based on immunomagnetic separation and biological catalysis. The method comprises the following steps: separating and enriching target microbes through a first bio-recognition element modified immunomagnetic element to improve the concentration and the purity of the target microbes; simultaneously modifying a nano-element with a second bio-recognition element and a predetermined enzyme, introducing an enzyme for catalyzing a biological reaction to a detection system in a sandwich manner, and changing the pH value of a catalysis solution by using the predetermined enzyme catalyzed biological reaction; and adding a pH indicator, and determining the content of the target microbes in the sample to be detected according to the color change of the pH indicator. The method integrates the purification and enrichment characteristics of immunomagnetic separation, the catalysis amplification characteristic of biological catalysis and the simple determination characteristic of the pH indicator, and also has the advantages of effective improvement of the detection sensitivity, shortening of the detection time, simplification of the detection process, and reduction of the detection cost.

The invention discloses a method for detecting escherichia coli based on an immunomagnetic separation technique and a bioluminescence technique. The method comprises the following steps of (1) coupling biotin and an escherichia coli antibody, so as to obtain the biotinylated escherichia coli antibody; (2) mixing the biotinylated escherichia coli antibody and streptavidin-modified magnetic nanoparticles, so as to prepare a magnetic nanometer probe; (3) flushing the magnetic nanometer probe by a PBS (phosphate buffer saline) buffer solution, adding the magnetic nanometer probe into an escherichia coli solution, and enabling the magnetic nanometer probe to capture the escherichia coli; (4) putting the solution after capturing the escherichia coli into a centrifuge tube, and enriching the magnetic nanometer probe captured with the escherichia coli; (5) cleaning the enriched sample by a cleaning solution, so as to obtain a solution for ATP (adenosine triphosphate) light emitting; enrichingand separating the magnetic nanometer probe by a magnetic separating frame; adding fluorescein and Mg<2+> into the solution after cracking, and detecting the fluorescent intensity of the solution, soas to obtain the number of the escherichia coli.

A method for separating components from a patient sample is provided. In particular, the present invention provides a method for the separation of red blood cells or red blood cell components from a patient sample by the use of magnetic beads.

A food-borne pathogenic bacteria quick detection method based on Gamma-Fe2O3@Au nano particle indirect enrichment and immunomagnetic separation, and belongs to the technical field of quick pathogen detection for food security. On dependence of a method for detecting pathogen in a food liquid sample, the specificity of an antibody I is combined with the target bacteria, the Gamma-Fe2O3@Au composite nano particle is utilized to prepare immuomagnetic beads of an antibody II to enrich target strains marked by the antibody I, the nano magnetic beads of the target bacteria are captured through separation, and then subjected to nitration to be converted into ferrous ions, and the ferrous ions are detected to indirectly detect whether the sample contains target pathogen. Under a certain condition, the quantity of the ferrous ions and the target bacteria show linear relation, so that the target bacteria can be quantificationally detected within a certain range. The food-borne pathogenic bacteria quick detection method can be used for quick detection of harmful pathogen in the food sample, and can be used for quick screening of large quantities of samples to be detected.

An apparatus and methods are provided for the magnetic separation of target bioentities. The apparatus include a fluid chamber and a magnetic element for drawing target bioentities toward a collection surface of the fluid chamber. The apparatus may include a positioning assembly operable to variable change the position and orientation of the fluid chamber relative to the magnetic element.

The invention provides a method for detecting and / or quantifying mammaglobin mRNA (messenger ribonucleic acid) in a sample. The method comprises the steps of providing first aptamers coupled with magnetic particles and second aptamers coupled with gold nanoparticles, mixing, preforming magnetic separation and detecting products of magnetic separation. The invention further relates to a to-be-detected blood sample pretreatment reagent, an intermediate product, a detection kit and the like, which are used in the method.