33 results about "Immobilized DNA" patented technology

The invention discloses a chip preparation method, a DNA or protein immobilization method, and a chip. The chip preparation method of the invention comprises performing weak passivation treatment after immobilization treatment, wherein the weak passivation treatment comprises contacting a weak passivation reaction solution containing a catalyst with a chip subjected to immobilization treatment, soas to promote binding of DNA or protein to the surface of a substrate, and to enable the DNA or protein to be sufficiently immobilized on the surface of the substrate. The preparation method of the invention increases the weak passivation treatment step after the immobilization treatment, so that the DNA or protein can be more fully immobilized on the surface of the substrate, the quality and efficiency of DNA or protein immobilization are improved, also DNA or protein is more fully immobilized, the relationship between the amount of the DNA or protein immobilized on the chip and the concentration of the DNA or protein initially added is more closely, and thus the immobilization amount of the DNA or protein is highly controllable, the repeatability is good, and a foundation is laid for preparing high-quality DNA or protein chips.

The present invention relates to a DNA polymerase immobilized by covalent bonding. More particularly, the present invention relates to an immobilized DNA polymerase whose activity is maximally preserved by masking the active site of the DNA polymerase and optimizing interaction of the masked molecule to the substrate material. In one embodiment, the average activity of the immobilized DNA polymerase is more than about 10% relative to that of the solution phase DNA polymerase. Further provided by the invention are methods and kits for performing polymerase chain reactions (PCR).

Compositions and methods for electrochemical detection and localization of genetic point mutations, common DNA lesions and other base-stacking perturbations within oligonucleotide duplexes adsorbed onto electrodes and their use in biosensing technologies are described. An intercalative, redox-active moiety (such as an intercalator or nucleic acid-binding protein) is adhered and / or crosslinked to immobilized DNA duplexes at different separations from an electrode and probed electrochemically in the presence or absence of a non-intercalative, redox-active moiety. Interruptions in DNA-mediated electron-transfer caused by base-stacking perturbations, such as mutations or binding of a protein to its recognition site are reflected in a difference in electrical current, charge and / or potential.

The invention belongs to the technical field of electrochemistry detection and chemical sensors for detecting 9-hydroxy fluorine based on a hairpin DNA modified gold electrode sensor, and relates to preparation of a hairpin DNA modified gold electrode capble of having electrochemical response to 9-hydroxy fluorine and detection on the 9-hydroxy fluorine with the electrode. Specifically, the synthetic sulfhydryl modified hairpin DNA is used as a raw material, the hairpin DNA is self-assembled to the surface of the gold electrode by the Au-S bond interaction to prepare the DNA modified electrode. The immobilized DNA electrode has high response to the 9-hydroxy fluorine, and the detection on the 9-hydroxy fluorine can be carried out according to the change of response of the electrochemistry to the impedance. The DNA sensor has the advantages of mild preparation condition, simplicity in operation, good stability and high sensitivity.

Compositions and methods for electrochemical detection and localization of genetic point mutations and other base-stacking perturbations within oligonucleotide duplexes adsorbed onto electrodes and their use in biosensing technologies are described. An intercalative, redox-active moiety (such as an intercalator or nucleic acid-binding protein) is adhered and / or crosslinked to immobilized DNA duplexes at different separations from an electrode and probed electrochemically in the presence or absence of a non-intercalative, redox-active moiety. Interruptions in DNA-mediated electron-transfer caused by base-stacking perturbations, such as mutations or binding of a protein to its recognition site are reflected in a difference in electrical current, charge and / or potential.

The present invention generally relates to methods and apparatuses for amplifying nucleic acid sequences using immobilized DNA polymerase. More particularly, it relates to methods and apparatuses useful for amplifying target nucleic acid sequences by forming a plurality of reaction regions in which polymerase chain reaction (PCR) can occur, positioning immobilized DNA polymerase in a specific reaction region, and circulating DNA through the reaction regions. The present invention provides those methods and apparatuses that allow simple separation and recovery of the DNA polymerase after the amplification, that can be operated not only with thermostable DNA polymerases but also with non-thermostable DNA polymerases, and that are simpler in their designs and processes so that they can be readily integrated into complex devices such as Lab-on-a-chip.

The present invention relates to a microfluidic device for extracting and isolating DNA from cells. The device includes a support having an inlet port for receiving a sample containing a cell, an outlet port for dispensing DNA isolated from the cell, and a microfluidic channel disposed within the support and extending from the inlet port to the outlet port. The microfluidic channel includes a micropillar array, an inflow channel disposed between the inlet port and the micropillar array, and an outflow channel disposed between the micropillar array and the outlet port. The micropillar array includes micropillars spatially configured to entrap, by size exclusion, the cell, to immobilize DNA released from the cell, and to maintain the immobilized DNA in elongated or non-elongated form when hydrodynamic force is applied to the microfluidic channel. Systems and methods of making and using the device are also provided herein.

A system with immobilized DNA is used in the fields of medicine, environmentology or criminology as an analytical tool in the analysis of nucleic acid. The immobilized DNA is provided with a biocatalytically active marker, such as an enzyme, an with an inhibitor substance which reversibly inhibits catalytic activity, or in addition to the immobilized biocatalytic marker, the immobilized DNA is provided with a substance which can reversibly inhibit the catalytic activity of the marker. Alternatively, an immobilized biocatalytically active marker can be provided with DNA as a scavenger which includes a substance as an inhibitor which can reversibly inhibit the activity of the marker. In another alternative, it is possible to use a complex including a molecule binding double-stranded DNA and a substance as an inhibitor which can reversibly inhibit the activity of the marker by interacting with the immobilized biocatalytically active marker. In all cases, the inhibitor or compound including an inhibitor and a molecule which can bind double-stranded DNA interacts with the biocatalytically active marker and defines the inactive state of the system. When the DNA, which is to be analyzed, is bonded, especially hybridized, to the DNA scavengers, the interaction between the biocatalytically active marker and the inhibitor is cancelled as a result of the formation of the double strand. The system is thus shifted from a first state into a second state defining the active state. A carrier with integrated microelectrodes is provided in the associated device, whereby the enzyme is either immobilized therein or is contained in a polymer network in the vicinity of the microelectrodes.

The purpose of the present invention is to provide a convenient and fast method for immobilizing DNA on a substrate and a method for accurately detecting DNA, and the density of DNA immobilized by the method is as high as that of the traditional method. A substrate activation kit is provided, which includes phosphate buffered saline at pH 6, solution A (aqueous) of N-hydroxysuccinimide and 1-[3-(dimethylamino)propyl]3-ethylcarbodi Solution B of imine (dioxane solution); a method for detecting DNA is provided, which is characterized in that the DNA is spotted onto the substrate activated with the above-mentioned activation kit, and then hybridized with fluorescently labeled DNA with the spotted DNA.

The invention relates to a method for efficiently screening out DNA chain scission injury protective drugs. The method is characterized by comprising the steps that DNA with one end modified by FAM and the other end modified by amino is fixed to a magnetic microsphere surface through a covalent bond, and immobilized DNA is obtained; a drug solution is added into the immobilized DNA, and DNA with drugs is obtained; in vitro exposure is carried out on the DNA with the drugs, and exposure DNA is obtained; magnetic separation is carried out on the exposure DNA, exposure ingredients and reaction impurities are separated away, and DNA free of chain scission is retained; an enzyme-labeled FAM antibody is added into the DNA free of chain scission, the enzyme-labeled FAM antibody and the FAM at the free end of the DNA free of chain scission have an immunoreaction, and DNA is obtained after the immunoreaction; an enhanced chemiluminescent is added into the DNA obtained after the immunoreaction, the high-sensitivity chemiluminiscence method is adopted for detecting the DNA obtained after the immunoreaction, and detection signals are obtained; the detection signals are compared with comparison group signals, and whether the drugs protect the DNA or not is judged. The method can reduce false positives, and has the practical value.

The present invention provides a method of amplifying target DNA by PCR or multiplex PCR on a microarray using array-immobilized DNA probes synthesized in a common area on the microarray by a maskless array synthesizer (MAS). The MAS constructed array-immobilized DNA probes include a universal primer linked to a sequence-specific probe, and optionally a calibrated probe for use in quantifying amplified target DNA.

The invention specifically relates to a co-immobilization method for DNA polymerase and reverse transcriptase, belonging to the field of enzyme engineering. The method comprises the following steps: adding sodium alginate into a first buffer, then adding DNA polymerase, carrying out mixing and immobilizing, and then carrying out vacuum drying so as to obtain immobilized DNA polymerase; adding a second buffer and reverse transcriptase into the immobilized DNA polymerase, carrying out mixing and immobilizing, then carrying out vacuum drying and then carrying out washing with the second buffer; and then carrying out lyophilization so as to obtain the co-immobilized DNA polymerase and reverse transcriptase. According to the invention, DNA polymerase and reverse transcriptase are co-immobilizedon a same carrier, so one-step conversion of a RT-PCR reaction is realized, and the catalytic properties of DNA polymerase and reverse transcriptase are integrated to eliminate certain interference factors, and thus, the overall catalytic efficiency of DNA polymerase and reverse transcriptase to RT-PCR reactions is improved.

The invention belongs to the field of enzyme engineering, in particular to a co-immobilization method of DNA polymerase and reverse transcriptase. The method comprises the following steps: adding sodium alginate to the first buffer solution, then adding DNA polymerase, mixing, fixing, and vacuum-drying to obtain immobilized DNA polymerase; adding the second DNA polymerase to the immobilized DNA polymerase The second buffer solution and the reverse transcriptase are mixed, fixed, vacuum-dried, and then washed with the second buffer solution; freeze-dried to obtain co-immobilized DNA polymerase and reverse transcriptase. By co-immobilizing DNA polymerase and reverse transcriptase on the same carrier, the present invention can not only realize the one-step conversion of RT-PCR reaction, but also can combine the catalytic properties of the two, and can eliminate some interference factors, thereby improving The overall catalytic efficiency of the two on the RT-PCR reaction.

The invention relates to a method for shortening DNA sequencing of a DNA template and application thereof. The method comprises the following steps of: (1) determining a small segment of sequence which is fixed in the DNA template by synthesizing or adopting a connecting sequencing method; (2) stopping the sequencing of sequencing primers, adding four kinds of dNTPs monomer extension sequencing primer strands, and making the DNA template become double strands; (3) shortening the DNA template: processing by using restriction enzyme to preset a connexon with an enzyme recognition sequence; and fracturing a small segment of sequence in the determined DNA template; (4) connecting the sequencing primer and a double stranded oligonucleotide segment with the enzyme recognition sequence on the cut and shortened DNA template; (5) denaturing, removing unfixed DNA strands, and obtaining the DNA template again; (6) hybridizing the sequencing primer, and continuously determining the small segment of sequence fixed in the DNA template; and (7) repeating the step (2) to the step (6) until the sequencing of the undermined DNA template is completed.

The present invention uses streptavidin-modified magnetic beads-SELEX technology to screen through the immobilized DNA library method, and obtains 4 ssDNA adaptations with high affinity and specificity to 6'-sialyllactose from 3187 sequencing results Using ssDNA aptamer as 6'-sialyllactose biorecognition element, catalytic hairpin self-assembly as signal amplification unit, and quantum dots as signal label, a fluorescent biosensor based on fluorescence resonance energy transfer was constructed to detect6 '‑sialyllactose. The invention provides a recognition element and a detection method with high affinity, high specificity, easy modification and labeling for the detection of 6'-sialyllactose.

The present invention relates to a DNA polymerase immobilized by covalent bonding. More particularly, the present invention relates to an immobilized DNA polymerase whose activity is maximally preserved by masking the active site of the DNA polymerase and optimizing interaction of the masked molecule to the substrate material. In one embodiment, the average activity of the immobilized DNA polymerase is more than about 10% relative to that of the solution phase DNA polymerase. Further provided by the invention are methods and kits for performing polymerase chain reactions (PCR).

The invention relates to a method for efficiently screening out DNA chain scission injury protective drugs. The method is characterized by comprising the steps that DNA with one end modified by FAM and the other end modified by amino is fixed to a magnetic microsphere surface through a covalent bond, and immobilized DNA is obtained; a drug solution is added into the immobilized DNA, and DNA with drugs is obtained; in vitro exposure is carried out on the DNA with the drugs, and exposure DNA is obtained; magnetic separation is carried out on the exposure DNA, exposure ingredients and reaction impurities are separated away, and DNA free of chain scission is retained; an enzyme-labeled FAM antibody is added into the DNA free of chain scission, the enzyme-labeled FAM antibody and the FAM at the free end of the DNA free of chain scission have an immunoreaction, and DNA is obtained after the immunoreaction; an enhanced chemiluminescent is added into the DNA obtained after the immunoreaction, the high-sensitivity chemiluminiscence method is adopted for detecting the DNA obtained after the immunoreaction, and detection signals are obtained; the detection signals are compared with comparison group signals, and whether the drugs protect the DNA or not is judged. The method can reduce false positives, and has the practical value.