3545 results about "Magnetic bead" patented technology

The present invention provides methods for determining a nucleic acid sequence by performing successive cycles of duplex extension along a single stranded template. The cycles comprise steps of extension, ligation, and, preferably, cleavage. In certain embodiments the methods make use of extension probes containing phosphorothiolate linkages and employ agents appropriate to cleave such linkages. In certain embodiments the methods make use of extension probes containing an abasic residue or a damaged base and employ agents appropriate to cleave linkages between a nucleoside and an abasic residue and/or agents appropriate to remove a damaged base from a nucleic acid. The invention provides methods of determining information about a sequence using at least two distinguishably labeled probe families. In certain embodiments the methods acquire less than 2 bits of information from each of a plurality of nucleotides in the template in each cycle. In certain embodiments the sequencing reactions are performed on templates attached to beads, which are immobilized in or on a semi-solid support. The invention further provides sets of labeled extension probes containing phosphorothiolate linkages or trigger residues that are suitable for use in the method. In addition, the invention includes performing multiple sequencing reactions on a single template by removing initializing oligonucleotides and extended strands and performing subsequent reactions using different initializing oligonucleotides. The invention further provides efficient methods for preparing templates, particularly for performing sequencing multiple different templates in parallel. The invention also provides methods for performing ligation and cleavage. The invention also provides new libraries of nucleic acid fragments containing paired tags, and methods of preparing microparticles having multiple different templates (e.g., containing paired tags) attached thereto and of sequencing the templates individually. The invention also provides automated sequencing systems, flow cells, image processing methods, and computer-readable media that store computer-executable instructions (e.g., to perform the image-processing methods) and/or sequence information. In certain embodiments the sequence information is stored in a database.

A method of purifying a biological component found in a biological sample by extracting the biological component from the biological sample. The method is performed using a microfluidic device having at least one well for receiving the biological sample and at least one channel for introducing and removing fluids. A plurality of magnetic beads having a factor with an affinity for the biological component is introduced to the well together with a suitable biological sample. The biological sample is manipulated to release the biological component in proximity to the magnetic beads which are then segregated within the well while removing the biological sample. An elution solution for the biological component is introduced to the well and the elution solution together with the biological component are withdrawn therefrom.

The present invention includes methods of enriching rare cells, such as cancer cells, from biological samples, such as blood samples. The methods include performing at least one debulking step on a blood sample and selectively removing at least one type undesirable component from the blood sample to obtain a blood sample that is enriched in a rare cell of interest. In some embodiments magnetic beads coupled to specific binding members are used to selectively removed components.

Disclosed herein is a device comprising a pair of bellows pumps configured for efficient mixing at a microfluidic scale. By moving a fluid sample and particles in suspension through an aperture between the paired bellows pump mixing chambers, molecular collisions leading to binding between the particles and ligands in the sample are enhanced. Such devices provide an alternative for mixing that does not use a vent and can be used with a variety of particles in suspension such as magnetic beads to capture or purify useful cells and molecules.

A detecting device for biochemical detections is provided. The detecting device includes a first substrate, a magnetic layer located on the first substrate, an isolation layer located on the magnetic layer, at least a first electrode located on the isolation layer, a first dielectric layer located on the first electrode, a first hydrophobic layer located on the first dielectric layer, a second substrate, at least a second electrode located on the second substrate and having a cathode and an anode, a second dielectric layer located on the second electrode and a second hydrophobic layer located on the second dielectric layer. The first electrode is zigzag-shaped, and the cathode and the anode of the second electrode are comb-shaped and interlaced with each other.

The invention relates to a multichannel micro-fluidic chip specially used for AIDS diagnosis and comprising quasi-one-dimensional sensitive electrodes, belonging to the field of test. One of the hopes in the progress of medical techniques is to quickly diagnose AIDS at low cost. The invention provides a micro-fluidic chip that uses a plurality of AIDS characteristic antibodies to simultaneously detect and quickly diagnose AIDS. The chip is provided with three micro liquid storage tanks. The key points of the proposal lie in that the inner of the chip contains capillary channels of parallel structure, the parallel structure contains four micro-channels mutually connected in parallel, four working electrodes of bead string structure in total are respectively arranged in the four micro-channels, the substances on the superficial coats of the four working electrodes of bead string structure are respectively four antibody substances, namely, AIDS antibodies p24, gp41, gp120 and gp36. The application of the chip is conducive to increasing the diagnosis efficiency of AIDS as shown by the structural characteristics.

The invention relates to a special micro-fluidic chip for cholera diagnosis with one-dimensional self-assembly magnetic bead chain electrodes, belonging to the field of testing. Rapid diagnosis of fulminating infectious disease cholera with low cost is one of many expectations in the development of medical technology, and the invention provides a micro-fluidic chip for simultaneously detecting and rapidly diagnosing cholera by using multiple characteristic antibodies of cholera. The chip is provided with three micro liquid storage tanks, and the invention is characterized in that capillary passages in parallel configuration contain in the chip, the parallel configuration contains four micro-passages that are mutually in parallel, four magnetic bead chain working electrodes are respectively installed inside the four micro-passages, the surface substances of the four magnetic bead chain working electrodes are respectively four antibody substances that are cholera TP0821 antibody, cholera TP0319 antibody, cholera TP0624 antibody and cholera O139 mycoprotein antibody. The integrated structure and the appearances of specific magnetic bead chain working electrodes facilitate to improve the diagnosis efficiency of cholera diseases.

A miniaturized, integrated, microfluidic device pulls materials bound to magnetic particles from one laminar flow path to another by applying a local magnetic field gradient. The device removes microbial and mammalian cells from flowing biological fluids without any wash steps. A microfabricated high-gradient magnetic field concentrator (HGMC) is integrated at one side of a microfluidic channel. When magnetic particles are introduced into one flow path, they remain limited to that flow path. When the HGMC is magnetized, the magnetic beads are pulled from the initial flow path into the collection stream, thereby cleansing the fluid. The microdevice allows large numbers of beads and materials to be sorted simultaneously, has no capacity limit, does not lose separation efficiency as particles are removed, and is useful for cell separations from blood and other biological fluids. This on-chip separator allows cell separations to be performed in the field outside of hospitals and laboratories.

A centrifugal force-based microfluidic device for nucleic acid extraction and a microfluidic system are provided. The microfluidic device includes a body of revolution; a microfluidic structure disposed in the body of revolution, the microfluidic structure including a plurality of chambers, channels connecting the chambers, and valves disposed in the channels to control fluid flow, the microfluidic structure transmitting the fluid using centrifugal force due to rotation of the body of revolution; and magnetic beads contained in one of the chambers which collect a target material from a biomaterial sample flowing into the chamber, wherein the microfluidic structure washes the magnetic beads which collect the target material, and separates nucleic acid by electromagnetic wave irradiation from an external energy source to the magnetic beads. The microfluidic system includes the microfluidic device; a rotation operating unit which rotates the body of revolution; and an external energy source which irradiates electromagnetic waves.

The invention provides for devices and methods for interfacing microchips to cartridges and pneumatic manifolds. The design of the cartridges, microchips, and pneumatic manifolds can allow for the use of magnetic forces to capture magnetic beads in a chamber formed between the microchip and the cartridge or a chamber within the microchip. The devices of the invention can be used for mRNA amplification and purification.

Each layer in the magnetic multilayer film is a closed ring or oval ring and the magnetic moment or flux of the ferromagnetic film in the magnetic unit is in close state either clockwise or counterclockwise. A metal core is put in the geometry center position in the close-shaped magnetic multilayer film. The cross section of the metal core is a corresponding circular or oval. A MRAM is made of the closed magnetic multilayer film with or without a metal core. The close-shaped magnetic multilayer film is formed by micro process method. The close-shaped magnetic multilayer film can be used broadly in a great variety of device that uses a magnetic multilayer film as the core, such as MRAM, magnetic bead in computer, magnetic sensitive sensor, magnetic logic device and spin transistor.

A process for extracting hemopoietic stem cells from the placenta of healthy puerperant to create hemopoistic stem cell bank features that the mechanical, enzyme digestive and monoclonal antibody-magnetic bead method is used to extract blood stem cells from placenta, and concentrate and purify them. Its advantages are high activity and high concentration.

A pharmaceutical dosage form such as a capsule capable of delivering therapeutic agents into the body in a time-controlled or position-controlled pulsatile release fashion, is composed of a multitude of multicoated particulates (beads, pellets, granules, etc.) made of one or more populations of beads. Each of these beads except an immediate release bead has at least two coated membrane barriers. One of the membrane barriers is composed of an enteric polymer while the second membrane barrier is composed of a mixture of water insoluble polymer and an enteric polymer. The composition and the thickness of the polymeric membrane barriers determine the lag time and duration of drug release from each of the bead populations. Optionally, an organic acid containing intermediate membrane may be applied for further modifying the lag time and/or the duration of drug release. The pulsatile delivery may comprise one or more pulses to provide a plasma concentration-time profile for a therapeutic agent, predicted based on both its pharmaco-kinetic and pharmaco-dynamic considerations and in vitro/in vivo correlations.

The invention provides an automatic extraction device and an automatic extraction method of a nucleic acid based on nano magnetic beads. The device comprises a base (1), as well as a motor, a magnetic bar (6), a magnetic bar clamping mechanism (3), a stirring sleeve (5), a stirring sleeve clamping mechanism (10), a deep hole plate (2), a control circuit and an upper computer which are arranged on the base (1). According to the device and the method which are provided by the invention, the nucleic acid is combined with the nano magnetic beads; and then, the nucleic acid is extracted from a nucleic acid cracking liquid under the attraction of the magnetic bar (6). Thus, the consistency of sample treatment is guaranteed to a great extent; the human interference is reduced; and the cross interference risk is decreased. The device and the method provided by the invention are suitable for the pretreatment of sample inspection in the medicinal field, the biological field, the agricultural field and the like.

A new method to capture, purify and expand antigen-specific T lymphocytes has been developed using magnetic beads coated with recombinant MHC class I molecules. This method was optimized using homogenous populations of naive T cells purified from mice transgenic for the 2C T cell receptor (TCR). These T cells were captured on beads coated with MHC class I molecules and the relevant antigenic peptides. MHC and peptide specificity was confirmed by the usage of irrelevant MHC peptide combinations. An enrichment of 800 to 1600 fold was measured, using 2C T cells mixed with irrelevant T cells, starting from a 2C T cell frequency of 1/3000. The same approach was used to purify antigen-specific CD8⁺ T cells from total CD8⁺ T cells from naive mice. The recovered cells could be expanded and specifically kill target cells in vitro; they had a significant effect in vivo as well. We expect this procedure to be suitable to purify and expand in vitro tumor- and virus-specific killer T cells for use in cell therapy.

The present invention relates to diagnostic assays whereby the detection means is based on electrochemical reactions. This means that the label to be detected provides an electric signal. Preferred labels are enzymes giving such a signal. Provided is a flow cell whereby a solid phase is provided in a flow stream of the sample, in close proximity to a working electrode to detect any electrical signal. In a typical embodiment, a sample is mixed with molecule having specific binding affinity for an analyte of which the presence in the sample is to be detected, whereby said specific binding molecule is provided with a label. The conjugate of labelled specific binding molecule and analyte is then immobilized on the solid phase in the vicinity of the working electrode, the flow cell is rinsed with a solution and afterwards a substrate solution for the label (an enzyme) is provided upon which an electrical signal is generated and can be detected by the working electrode. The methods and devices of the present invention are particular useful for liquids which comprise many substances that may disturb measurement in conventional assays. The design of the flow cell allows for removal of said interfering substances before measurement. In a preferred embodiment at least part of the solid phase is provided in the form of magnetic beads. In this embodiment the solid phase can be mixed with the sample thereby creating a longer reaction time, a better sensitivity and a higher speed of the assay.

Disclosed is an improvement in methods for nucleic acid and immunological bioassays. The methods comprise a step for “sweeping” paramagnetic bead: target molecule complexes so as to capture them with an affinity capture agent on a test pad by moving a magnetic force field from outside to inside the test pad area so as to bring into contact the paramagnetic complexes with the capture agent, while sweeping any unbound paramagnetic material off the test pad by moving the magnetic field from inside to outside the test pad area. Surprisingly, the paramagnetic complexes are rapidly affinity-extracted from the moving magnetic field.

A device for transporting magnetic or magnetisable microbeads (25) in a capillary chamber (14) comprises a permanent magnet (10) or an electromagnet (11) for subjecting the capillary chamber to a substantially uniform magnetic field, to apply a permanent magnetic moment to the microbeads (25). At least one planar coil (22) and preferably an array of overlapping coils are located adjacent to the capillary chamber (14) for applying a complementary magnetic field on the microbeads parallel or antiparallel to said substantially uniform magnetic field, to drive the microbeads. An arrangement is provided for switching the current applied to the coil(s) (22) to invert the field produced thereby, to selectively apply an attractive or repulsive driving force on the microbeads (25). The device is usable to transport microbeads for performing chemical and biochemical reactions or assay, as is done for instance in clinical chemistry assays for medical diagnostic purposes.

A sensor for a selected target species has (a) a substrate which has been chemically modified by attachment of substrate modifiers; (b) one or more magnetically active beads which have been chemically modified by attachment of bead modifiers, where these bead modifiers will have a binding affinity for the substrate modifiers in the presence of the target species, and a measurably different binding affinity for the substrate modifiers in the absence of the target species; (c) an adjustable source of a magnetic field for exerting a force on the beads; and (d) an imaging system, for observing and counting beads bound to the substrate. In a preferred embodiment, the invention further has a system for identifying clusters of beads, and for removing the effect of such clusters from measurements of the target analyte. As with other assays, the sensor relies on the ability of certain molecules to bind with specific target (analyte) molecules. By coating the beads and the substrate with appropriate molecules, the beads will (or will not) bind specifically to the substrate in the presence (or absence) of the target molecule. When a magnetic field is applied to the substrate, the magnetic beads will be pulled away from the substrate. If the beads are specifically bound to the substrate, however, the beads will be retained on the substrate, indicating the presence (or absence) of the target species.

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.

The invention discloses a method and an automatic instrument device for enriching and extracting target cells and separating single cells by using a positive magnetic bead method and performing immunity and molecular biology identification and analysis on single cells. By the method and the instrument device, the on/off of a capture magnet and a release magnet is controlled by various methods to complete target cell searching, capturing, cleaning and releasing operation once or for multiple times, so that the target cell detection sensitivity and stability are improved. When the capture magnet searches and captures the target cells, the search line is circular, square, comb-shaped, S-shaped or U-shaped. In addition, the captured substances are filtered, most free micro magnetic beads are removed, the purity of the product is further improved and the product can be used as a good experimental material. By combining a special filter and the adsorption of the capture magnet, more than 95 percent of free micro magnetic beads can be effectively removed. Meanwhile, the types of the single cells are identified and biological characteristics of the single cells are analyzed by an immunofluorescence staining method and a method in molecular biology, and effective biological indexes are provided for clinical diagnosis and treatment of cancers.

Disclosed are methods and apparatuses for separating cells using magnets and droplet type cell suspension according to the present invention, which may effectively separate cells by forming droplet type cell suspension with cell suspension sample containing cells to which magnetic beads are coupled and applying magnetic force to the droplet type cell suspension. The apparatus of separating cells according to the present invention includes: a droplet type cell suspension forming part for forming a droplet type cell suspension under a lower part of the droplet type cell suspension forming part with cell suspension sample containing cells to which magnetic beads are coupled; a cell suspension inlet for supplying the droplet type cell suspension forming part with the cell suspension sample; a magnet for applying magnetic force to the droplet type cell suspension; a cell buffer inlet for supplying the droplet type cell suspension with cell buffer; and a temperature maintaining part for maintaining a temperature of the droplet type cell suspension.