46 results about "Dna immobilization" patented technology

A substrate with a charged surface coated with one or more bilayers of oppositely charged polyelectrolytes. Subsequent optional bilayers of polyelectrolytes must bear alternating opposite charges. The final or top layer may be activated for biomolecular attachment.

This invention relates to substrates for use in immobilizing biomolecules. More particularly, the invention relates to substrates (e.g. glass slides) having a coating of polylysine covalently attached to a silane layer coating the slide, wherein the polylysine compound has a functional NH2 group which can be coupled directly, indirectly, covalently, or non-covalently to a biomolecule (e.g., a DNA or RNA molecule). Even more particularly, the invention relates to specific prescribed addition of ethanalomine to the polylysine thereby forming a mixture which dramatically enhances the effectiveness of the polylysine for immobilizing DNA. Among other applications, the polylysine coated substrates can be used in the preparation of high density arrays for performing hybridization assays

The invention provides a portable copper ion concentration detection method based on click chemistry and belongs to the field of analytical chemistry. Under the condition that sodium ascorbate reduces cupric into cuprous as a catalyst, a 1,3-dipole cycloaddition reaction is carried out between NDA modified with an azide group and DNA modified with an alkynyl group, so that DNA modified with cane sugar invertase is fixed on magnetic beads; The magnetic beads are separated from a solution, the cleaned magnetic beads are dissolved into a cane sugar solution to carry out enzymatic hydrolysis, and then a reaction solution after enzymatic hydrolysis is measured by adopting a blood glucose meter, so that copper ion concentration can be detected. The portable copper ion concentration detection method provided by the invention takes the blood glucose meter as a platform and can portably and quickly detect the copper ion concentration on site; and the portable copper ion concentration detection method can be applied to copper ion detection in a human body serum sample, and the portable copper ion concentration detection method has the advantages of easy operation, low cost, high sensitivity and good specificity.

It is intended to provide a method whereby DNA can be conveniently and rigidly immobilized on a substrate at such a high density as achieved by the conventional methods and a method of accurately detecting DNA. A substrate activation kit comprising a phosphate buffer (pH6), a solution A (an aqueous solution) of N-hydroxysuccinimide and a solution B (a dioxide solution) of 1-[3-(dimethylamino) propyl]3-ethylcarbodiimide; and a method of detecting DNA characterized by comprising spotting DNA on a substrate having been activated by using the above activation kit and then hybridizing the spotted DNA with fluorescence labeled DNA.

It is intended to provide a method of reusing a DNA-immobilization substrate whereby the expensive DNA-immobilization substrate can be efficiently utilized and a reusable DNA-immobilization substrate having the same performance as a new product without any trouble in practical use can be provided. Namely, a method of reusing a DNA-immobilization substrate characterized in that, to remove DNA from a DNA-immobilization substrate carrying the DNA immobilized by an acid-amide bond via an oligonucleotide to thereby enable the immobilization of a fresh DNA, the acid-amide bond between the substrate and the DNA is hydrolyzed with an acid or an alkali.

The invention discloses a preparation method of a working electrode of a photoelectric sensor. The preparation method includes the following steps: cleaning an ITO electrode, and then drying to obtain an electrode A; dropwise adding a titanium dioxide colloidal solution on the surface of the electrode A, drying, then calcining, and cooling to obtain an electrode B; placing the electrode B in a poly(diallyldimethylammonium chloride) aqueous solution, soaking, cleaning, next placing in a carboxylated quantum dot colloidal solution, soaking, and cleaning to obtain an electrode C; fixing a probe DNA on the electrode C to obtain an electrode D; dropwise adding a gold nanoparticle-labelled target DNA onto the electrode D, and making the gold nanoparticle-labelled target DNA hybridized with the probe DNA, to obtain an electrode E; and activating the electrode E, fixing an organic dye sensitizing agent on the surface of the electrode E, and cleaning to obtain the working electrode of the photoelectric sensor. The invention also discloses the photoelectric sensor. The photoelectric sensor has the characteristics of high sensitivity, good specificity, simple and convenient detection method, and economic cost.

The invention relates to a magnetic-bead-process-based kit for extracting free DNAs (deoxyribonucleic acids) and an application method thereof. The kit comprises a DNA fixation combination solution, a first magnetic bead suspension, a cleaning solution, a genome DNA removal solution, a second magnetic bead suspension and an elution solution which are respectively packaged independently. The kit can be used for directly extracting free DNAs from the whole blood sample. The object for extracting and purifying free DNAs is widened from the serum or plasma to the whole blood sample, and the free DNA extraction step is extended forward to the blood preliminary treatment, thereby greatly reducing the original steps for extracting free DNAs from blood. Besides, the kit can also be used for extracting and purifying free DNAs from a plasma or serum sample. The kit can be used for removing genome DNA interference. The kit can be used for removing trace genome DNAs mixed in the whole blood, plasma or serum, thereby lowering the subsequent testing interference. Different reagents in the kit are compounded, so that the free DNA extraction efficiency and purity are maximally ensured.

The invention discloses a method for detecting a potassium ion by preparing a biosensor based on a G-quadruplex and a gold nanoparticle, and belongs to the field of the biosensor. A detection method comprises the following steps of: modifying the gold nanoparticle on the surface of a gold electrode by taking para-aminothiophenol (p-ATP) as a medium, fixing a DNA (Deoxyribose Nucleic Acid) marked by ferrocene (Fc) and capable of forming a G-quadruplex structure onto the surface of the gold nanoparticle by a sulfydryl self-assembly action, and taking the DNA as an aptamer to prepare an electrochemistry biosensor to detect the potassium ion. The method for detecting the potassium ion by preparing the biosensor based on the G-quadruplex and the gold nanoparticle has the advantages that the detection is simple and quick, the sensitivity is high, the real-time detection can be carried out on the potassium ion, the minimum detection concentration to the potassium ion reaches 0.1 mM, and the linear range of the detection is large. In a concentration range of 0.1-1 mM, a square wave volt-ampere peak current is in a well linear relation with the concentration of the potassium ion; and in a concentration range of 1-30 mM, the square wave volt-ampere peak current is in a well linear relation with the logarithm of the concentration of the potassium ion.

The invention belongs to the technical field of chemical and biochemical medicines, particularly relates to a DNA fixed nano hydrogel microsphere, a preparation method of the DNA fixed nano hydrogel microsphere and a nucleic acid aptamer compound and an application of the DNA fixed nano hydrogel microsphere as a tumor targeting preparation. The preparation method is simple, only a segment of single-stranded DNA is synthesized at one end of the nucleic acid aptamer as a connecting arm when the nucleic acid aptamer is synthesized, and the sequence of the DNA connecting arm and the DNA sequence on the surface of the nano material of the nano hydrogel microsphere can be complemented and paired. One or a plurality of nucleic acid can be matched and connected on the surface of the nano materialat one time by co-incubation in aqueous solution so as to obtain the drug delivery carrier with the specific targeting function. According to the method, one or more nucleic acid aptamers can be connected on the surface of the drug delivery carrier at one time in a base complementary pairing mode; the base complementary pairing can be carried out in aqueous solution; reaction conditions are mild and easy to control; and the preparation process is very simple.

The invention provides a method for detecting lead ions based on combination of fluorescence quantitative PCR (polymerase chain reaction) and nuclease GR-5. The method comprises steps of (1) immobilizing nuclease GR-5 and complementary DNA (deoxyribonucleic acid) onto the inner surface of a PCR reaction vessel; (2) adding a sample to be tested into the PCR reaction vessel obtained in step (1), wherein when lead ions exist, in the presence of the nuclease GR-5, the complementary DNA breaks at the ribonucleotide so as to generate a short nucleic acid chain; (3) washing the PCR reaction vessel with citrate buffer solution so as to remove the nucleic acid molecules which are not immobilized; (4) adding an amplification primer into the PCR reaction vessel so as to carry out real-time fluorescence quantitative PCR on the immobilized complementary DNA; (5) confirming the concentration of the lead ions in the sample based on the Ct value of the real-time fluorescence quantitative PCR. According to the method, a brand-new biosensor with high selectivity and high sensitivity is provided and can be used for simply and rapidly detecting the concentration of lead ions in the sample.

The invention discloses a single molecule fluorescence apparatus and an application method thereof. The single molecule fluorescence apparatus comprises a lens-type full internal reference fluorescence microscope system, an image acquisition and processing system, a controllable magnetic tweezer system and a fluid pool system. The fluid pool system comprises a fluid pool fixed station, a fluid pool and an electric liquid flow pump; one side of the fluid pool fixed station is fixed on a sample stage of an inverted microscope of the full internal reference fluorescence microscope system, and the other side of the fluid pool fixed station is fixed with the fluid pool. The electric liquid flow pump and the fluid pool are connected; and the bottom of the fluid pool is equipped with more than one column of DNA fixed points. Columns of DNA fixed points are arranged in the fluid pool, so controllable fixing of a large amount of DNA can be realized. Through the transverse magnetic tweezer system, controllable drawing on a large amount of DNA molecules can be realized; and high precision observation on protein fluorescence signals can be realized without dyeing on DNA molecules.

The invention discloses a preparation method of a photoelectrochemical biosensor based on a cyclometalated iridium complex and application of the photoelectrochemical biosensor to thrombin detection.The biosensor uses the visible light-excited iridium complex as a photoelectrically active material, and the iridium complex is located on colloidal gold to prepare a gold nanometer signal probe. Capturing hairpin DNAs are immobilized on a modified ITO electrode to prepare a working electrode of the biosensor. A thrombin recognition system includes a specific recognition hairpin HP1 and an adjuvant hairpin HP2; in the presence of thrombin, a large number of secondary targets T-DNAs are released under the action of the excision enzyme ExoIII and hybridize with the capturing hairpin DNAs on theworking electrode so as to capture the gold nanometer signal probe, thereby realizing response to photocurrent signals; thrombin with different concentrations allows the amount of the signal probe connected to the working electrode to be different, so photocurrent intensities are different, and thus, quantitative detection of thrombin is realized. The method has the advantages of high sensitivityand good selectivity.

A conventional large-scale parallel pyrosequencing apparatus has the disadvantage that throughput decreases because much time and a large number of procedures are required for introduction of measurement beads, and analysis accuracy is deteriorated due to a reduction in accuracy of reagent replacement. There is provided an apparatus, wherein the apparatus includes a flow cell having a plurality of microfabricated reactors, and a camera opposed thereto, and DNA to be measured is fixed on the surfaces of beads having a specific gravity of 4 or greater, preferably zirconia beads. The flow cell is made horizontal when introducing the beads into the flow cell, and opposed to an optical axis of the camera when measuring an elongation reaction, the optical axis of the camera having a gradient with respect to the horizontal direction.

The invention provides a fluorescence quantitative in-situ hybridization (Q-FISH) method for determination of telomere length by using genomic DNA, wherein the method comprises the steps: the genomicDNA is fixed on a glass slide and then is hybridized with a telomere-specific PNA probe, and fluorescence data are collected; the method is also suitable for determination of the telomere lengths of split active and senescent cells; a plurality of telomere length parameters comprising the average telomere length, the telomere length variation and the frequency of abnormal-length telomeres can be obtained, and the defect that the telomere function is evaluated by single dependency of the average telomere length to obtain information is eliminated. The invention also provides a stronger-specificity telomere-specificity PNA probe, TTAGGG is shortened to 2 repetitions, the amount of the probe is reduced by half and a fluorescence signal is doubled. The invention also provides a telomere lengthstandard and a preparation method thereof, wherein the telomere length standard can be used for measuring the base length of each telomere and also can be used as calibration standard for different tests. If the automatic detection method is adopted, a large number of samples can be processed, and the method saves manpower compared with other methods.

The invention discloses a preparation method of a cyclometalated iridium complex biosensor for microRNA detection. The preparation method includes: designing and synthesizing a cyclometalated iridiumcomplex insertable into DNA dual strands as a photoelectric material; fixing capture hairpin DNA to a modified ITO electrode to obtain a working electrode of the biosensor herein; if target microRNA exists, hybridizing with the capture hairpin DNA fixed on the working electrode to release its neck portion, and allowing the released neck portion to hybridize with another two hairpin DNAs to triggerhybridization chain reaction, so that a long DNA dual-strand polymer is formed on the surface of the working electrode. Massive cyclometalated iridium complexes can be inserted into the polymer herein so as to amplify signals, and therefore, high-sensitivity detection of microRNA is achieved. The preparation method has the advantages of high sensitivity, good specificity, good stability and the like.

The invention belongs to the field of biological field, and more specifically relates to a method used for synthesis of a DNA library with a fixed length and a specific terminal sequence based on a template material. The method comprises following steps: fragmentation double chain DNA obtaining; DNA terminal restoration and 3' terminal tailing; 3'Biotin modified A1 joint connection; connection product purification; fixing of DNA onto a streptavidin containing solid phase; denaturation of double chain DNA into single chain DNA; primer 1 hybridization; reversible chemical modification of dNTPs extension basic group with deoxyribosyl 3' terminal hydroxyl; pentose 3' terminal hydroxyl restoration; extension of DNA of fixed length; 5' terminal trimming; tail end sequence selection; tail end sequence removing; and connection of joint used for molecular cloning. The method is capable of realizing construction of the library with region fixed length, specific terminal sequence, and high sequence variability, without reference genome, and library construction cost is reduced greatly.

The invention discloses a preparation method for leading the growth of a nanometer titanium dioxide film on the surface of a substrate by DNA immobilization. The method comprises the following steps that: (1) the substrate is cleaned and dried; (2) DNA molecules on the surface of the substrate are immobilized; and (3) the substrate treated by the step (2) is immersed into a 2 to 20 mM of TiCl4 aqueous solution containing hydrochloric acid and subject to the sedimentation of the nanometer titanium dioxide film. The method has no environmental pollution, realizes the immobilization and the ordered assembly of DNA and leads the assembly and growth of the nanometer titanium dioxide film at a low temperature with the substrate as a template. The nanometer titanium dioxide film prepared on the substrate surface by the method needs no high-temperature calcination, has a certain crystal structure, even film surface and strong adhesive force with the substrate surface and can be used for preparing a transparent conductive film and a self-cleaning surface of a solar battery and other functional devices.

The present invention relates to a method of preparing a surface-modified glass fiber by bonding an aminocalixarene derivative or an iminecalixarene derivative on the surface of a glass fiber to form a monolayer, a method of preparing a glass fiber where oligo-DNAs are immobilized by immobilizing oligo- DNAs having consecutive guanine bases on the glass fiber prepared according to said method, and a method of preparing a rapid genotyping kit using the glass fiber where various oligo-DNAs are immobilized according to said method, thereby allowing genotyping of various genes.

The invention relates to a method of immobilizing DNA on gel, in particular to a DNA immobilization method based on immobilization of nucleic acid on the gel and the application thereof. The immobilization method of a DNA sample comprises three steps of raw material selection, mixing and polyreaction. In the step of raw material selection, the selected raw materials and dosage are as follows: 10 percent of 10*TBE(pH13), 10-70 percent of 40 percent methacrylamide storage liquid, 1muL-5ml diluted degeneration amino terminal modified nucleic acid, 1-10 percent of N, N, N, N-tetramethyl ethylenediamine, 1-10 percent of 10 percent ammonium persulfate, and water. In the step of mixing, configured gel raw material is added with amino terminal modified nucleic acid to be mixed. The nucleic acid amount in the mixture is 10-1,000ng/3muL. In the step of polyreaction, 5muL mixture is put in a PCR reaction tube at 37 DEG C for 30min. After the polyreaction is finished, the mixture is molded into gel shape, and the amino terminal modified nucleic acid is immobilized by the polyreaction in the gel. The method has the advantages of high bearing capacity, immobilization of the terminal modified nucleic acid molecule by stable covalent bond formed between the molecule and a solid phase carrier and capacity of enduring dramatic conditions of the PCR reaction, etc.

The present invention is one medical adsorbent material. Short cotton velvet as material is processed successively through bleaching with sodium hypochlorite, treatment with sodium hydroxide and carbon disulfide to obtain cellulose xanthate derivative, which is heated and solidified at 85-95 deg.c for 1-3 hr through suspension process utilizing chlorobenzene and carbon tetrachloride as dispersing medium to obtain globular cellulose. The globular cellulose is then activated with epoxychloroproane in alkali condition and reacted with DNA solution to result in globular cellulose DNA immunoadsorbent with DNA content of 0.5-3.0 mg each milliliter resin. The said immunoadsorbent is superior to carbonized resin DNA immunoadsorbent in DNA fixing amount and adsorptivity and is one new product for treating systematic lupus erythematosus.

Accurate and sensitive sequencing in pyrosequencing is achieved by allowing complementary strand synthesis reaction to proceed homogeneously and completely in a short time while performing luminescence reaction for a sufficiently long time. DNA as a sequencing target is immobilized on the surface of a solid supporter. Nucleic acid substrates are injected from a dispenser to the supporter site where complementary strand synthesis is in turn performed rapidly and completely in a short time under a small reaction volume. Next, the supporter together with the product thereon is moved into a luminescence reaction solution where luminescence reaction is in turn performed. Thus, a DNA complementary strand synthesis reaction site and a luminescence reaction site are completely separated. The-supporter surface is also washed by dipping the supporter in the luminescence reaction solution that contains a luminescence reagent and an enzyme that degrades redundant nucleic acid substrates.