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.

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 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 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.

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 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.