249 results about "Complementary DNA" patented technology

Oligonucleotides and other macromolecules are provided which have increased nuclease resistance, substituent groups for increasing binding affinity to complementary strand, and subsequences of 2′-deoxy-erythro-pentofuranosyl nucleotides that activate RNase H. Such oligonucleotides and macromolecules are useful for diagnostics and other research purposes, for modulating the expression of a protein in organisms, and for the diagnosis, detection and treatment of other conditions susceptible to oligonucleotide therapeutics.

A method and device is disclosed for high speed, automated sequencing of nucleic acid molecules. A nucleic acid molecule to be sequenced is exposed to a polymerase in the presence of nucleotides which are to be incorporated into a complementary nucleic acid strand. The polymerase carries a donor fluorophore, and each type of nucleotide (e.g. A, T/U, C and G) carries a distinguishable acceptor fluorophore characteristic of the particular type of nucleotide. As the polymerase incorporates individual nucleic acid molecules into a complementary strand, a laser continuously irradiates the donor fluorophore, at a wavelength that causes it to emit an emission signal (but the laser wavelength does not stimulate the acceptor fluorophore). In particular embodiments, no laser is needed if the donor fluorophore is a luminescent molecule or is stimulated by one. The emission signal from the polymerase is capable of stimulating any of the donor fluorophores (but not acceptor fluorophores), so that as a nucleotide is added by the polymerase, the acceptor fluorophore emits a signal associated with the type of nucleotide added to the complementary strand. The series of emission signals from the acceptor fluorophores is detected, and correlated with a sequence of nucleotides that correspond to the sequence of emission signals.

The sequences of cDNAs encoding secreted proteins are disclosed. The cDNAs can be used to express secreted proteins or fragments thereof or to obtain antibodies capable of specifically binding to the secreted proteins. The cDNAs may also be used in diagnostic, forensic, gene therapy, and chromosome mapping procedures. The cDNAs may also be used to design expression vectors and secretion vectors.

A biconically tapered optical fiber serves as a biosensor at all optical wavelengths of interest ranging from UV to far IR at subfemtogram per mL sensitivity. The biconically tapered sensor detects biomaterials such as pathogenic species, proteins and DNA and others biological analytes. Although it uses the principles of evanescent fields, absorption, adsorption, fluorescence capture and retransmission through the fiber, the detection at the sub-nanogram per mL level is achieved primarily by adsorption or a surface activity due to a refractive index change. The geometry of the biconically tapered optical sensor affects its performance. The sensing modality is achieved in situ with a source connected at one end of a tapered fiber and a suitable detector at the other end. The tapered region is optionally immobilized with a recognition molecule such as an antibody to the target antigen or a complementary DNA strand. The sample is brought in contact with the tapered region either in batch mode or in a flow mode.

The sequences of cDNAs encoding secreted proteins are disclosed. The cDNAs can be used to express secreted proteins or fragments thereof or to obtain antibodies capable of specifically binding to the secreted proteins. The cDNAs may also be used in diagnostic, forensic, gene therapy, and chromosome mapping procedures. The cDNAs may also be used to design expression vectors and secretion vectors.

The present invention provides a gene chip for detecting common pathogen in dairy, which comprises a solid-phase vector and an oligonucleotide probe fixed on the solid-phase vector, wherein the oligonucleotide probe includes DNA fragment or its complementary DNA or RNA sequence selected from E. sakazakii, streptococcus pyogenes, staphylococcus aureus, Klebsiella pneumoniae, Klebsiella oxytoca, Listeria monocytogenes, salmonella and 16S-23S rDNA intergenic spacer region of Bacillus cereus, as well as ipaH gene of Shigella or gyrB gene of citrobacter freundii. The invention further provides a reagent box which uses the gene chip to detect pathogen in dairy. The gene chip and the reagent box of the invention for detecting pathogen in dairy are easy to operate, highly precise and greatly repeatable.

A method of identifying and quantifying small RNA molecules comprising a) isolating RNA molecules; b) ligating RNA adapter molecules onto the isolated RNA molecules to form RNA template molecules; c) forming complementary DNA molecules by transcribing the RNA template molecules; d) amplifying the complementary DNA molecules; e) obtaining sequence information of the complementary DNA molecules (and thereby the RNA from which it was derived); and f) obtaining quantity information of the complementary DNA molecules, wherein the quantity information of the DNA molecules reflects the quantity of the isolated RNA molecules is provided. Included in the invention is the identification of RNA molecules between 15 and 30 nucleotides in length.

Process for producing the enzyme D-amino acid oxydase of Rhodotorula gracilis in host cells. The process for the expression of the enzyme comprises isolating the complementary DNA corresponding to the messager RNA of the gene which codes for the D-amino acid oxydase of any strain of Rhodotorula gracillis producing said enzyme; fusing the fragment of DNA which codes for D-amino acid oxydase of Rhodotorula gracillis with a DNA sequence which contains a site of union to the ribosome and a high efficiency promoter sequence for the express of genes in host cells; inserting the DNA fragment into a plasmid appropriate for the host cell; cultivating the host cells transformed with said plasmid; and collecting the enzyme.

A method of identification of differentially expressed messenger RNA (mRNA) which consists of synthesizing from a set of sequences of mRNA sets of fragments of complementary DNA (cDNA), which are separated with the aid of gel electrophoresis and the pictures of separation of the cDNA from different types of cells are compared and fragments with differential signal intensity are identified. For formation of the set of fragments the cDNA is cleaved with the aid of restriction nucleases. A method of cloning of differentially expressed mRNAs consists of synthesizing from sets of sequences of mRNAs from different types of cells sets of fragments of complementary DNA (cDNA) which are separated with the aid of gel electrophoresis, the pictures of the separation of the cDNA from different types of cells are compared, fragments of cDNA with different signal intensities are separated from the gel, amplified with the aid of a polymerase chain reaction and cloned to a plasmid or phage vector. For the formation of the set of fragments one carries out cleavage of the cDNA with the aid of restriction endonucleases and uses only those fragments of cDNA that correspond to the 3' or 5' end regions of the mRNAs.

The invention belongs to the technical field of analytical chemistry and a chemical sensor, and discloses an electrochemical sensor for diagnosis of an ovarian SKOV-3 cancer cell, relating to a preparation method of a sandwich-type immunosensor based on graphene and a DNA (deoxyribonucleic acid) marker and application of the same in medical diagnosis. Antigens (human ovarian cancer) are indirectly tested with a glassy carbon electrode modified by graphene / antibody / antigen / DNA-labeled antibody / complementary DNA through catalytic oxidation based on guanine bases and adenine bases. The high electronic conductivity of the graphene is adopted, and the cost of the antibody marker is reduced. The immunosensor prepared based on the technical scheme can also be applied in detection of other types of cells has a wide scope of application. The sensor has high sensitivity, can be prepared simply, can be applied in detection any cancer cell, and has good prospects of application in medical diagnosis.

The present invention relates to a pixel and DNA cross dynamic chaotic cipher-based image encryption method and device. The method comprises the following processing of ranking the pixels of a plaintext image to obtain a first index matrix, and carrying out the first chaotic coding on the plaintext image according to the first index matrix to obtain a first intermediate image; ranking the rows andthe columns of the first intermediate image separately to obtain a row index matrix and a column index matrix, and scrambling the first intermediate image according to the row and column index matrixes to obtain a second intermediate image; converting each pixel in the second intermediate image into a 4-base DNA sequence, selecting eight kinds of coding rules satisfying a Watson-Crick complementrule according to the second chaotic coding, adopting the above eight kinds of coding rules to carry out the complementary DNA coding on each DNA sequence in the second intermediate image to obtain athird intermediate image, and then carrying out the DNA subtraction, add operation and xor operation on the third intermediate image to obtain a fourth intermediate image; carrying out the adjacent DNA coding on the fourth intermediate image to obtain a final ciphertext image.

The present invention belongs to the field of biosensing technologies, and relates to a method for preparing a ratio electrochemical aptamer sensor for detecting ochratoxin A, and the method is used for detecting the ochratoxin A (OTA). The ratio sensing policy is constructed by sequentially modifying ferrocene marked complementary DNA (Fc-cDNA), ochratoxin A aptamer (Aptamer) and auxiliary complementary DNA (hDNA) on a gold electrode, double current signals IFc and IMB (which are respectively oxidized electric currents of Fc and MB) are output by using a target-induced comformational change,and OTA is detected by using a ratio signal (IFc/IMB) quantization sum of IFc and IMB. The obtained ratio electrochemical aptamer sensor can implement highly sensitive and highly reliable detection onthe OTA, a detection linearity range is 10 pg/mL to 10 ng/mL, and a detection limit is 3.3 pg/mL. The present invention aims to develop a ratio electrochemical aptamer sensor that is high in sensitivity, good in selectivity, and high in reliability, and provide a reliable sensing platform for measuring OTA in an actual sample.

The present invention relates to one kind of method of detecting DNA crossbreeding and mispairing in raised sensitivity based on DNA base pairing principle. Nano gold particles in different sizes are used separately as the surfactant of quartz crystal microbalance and distinguishing amplifier as DNA detector. By means of the decoration of the metal surface of the quartz crystal microbalance with double-functional radical connecting agent, nano metal particles are fixed to the quartz crystal microbalance. Single-strand DNA probe is then fixed onto the nano metal decorated surface, and the DNA probe and the target DNA single strand to be detected are made to crossbred. The relatively longer target DNA has one part complementary with the probe DNA via being fixed onto the quartz crystal microbalance and the other part paired with the complementary DNA single strand connected to nano metal particles to raise the detection sensitivity to 10E(-16).

The invention provides a gene chip for detecting pathogens of lower respiratory tract, which comprises a solid phase carrier and an oligonucleotide probe fixed on the solid phase carrier, wherein the oligonucleotide probe comprises a sequence selected from one or more DNA sequences of staphylococcus aureus, 16s-23s rDNA intergenic spacer region of Klebsiella pneumoniae or Acinetobacter baumannii, 16S gene of pseudomonas aeruginosa or haemophilus influenzae, gyrB gene of streptococcus pneumoniae or legionella pneumophila and copB gene of moraxella catarrhalis or the complementary DNA or RNA sequence. The invention further provides a reagent kit containing the gene chip. The utilization of the gene chip and the reagent kit can detect the pathogens of the lower respiratory tract; furthermore, the operation is simple, the accuracy is high and the repeatability is strong.

This invention relates to the enhancement of feed efficiency and growth rate, and the reduction of fit accumulation to produce better quality meat by administration of an exogenous gene sequence comprising the complementary DNA sequence of growth hormone releasing factor to stimulate the production of the endogenous hormone peptide growth hormone. This invention further relates to methods for producing such gene sequence.

The invention belongs to the technical field of SPR sensors, and particularly relates to a SPR sensor made with a graphene/gold/D-type plastic optical fiber and a preparation method. The method comprises the following steps of: (1) forming a groove shaped sensing area in the fiber, and preparing a D-type fiber; (2) growing the graphene on a copper foil by using a chemical vapor deposition method,and directly evaporating a gold film onto the graphene through a thermal evaporation method, to obtain a gold/graphene/copper foil composite layer; (3) corroding the copper foil in the gold/graphene/copper foil composite layer, and moving the obtained graphene/gold film to a D-type optical fiber, to obtain the sensor. According to the preparation method, the gold is directly evaporated onto the graphene through the thermal evaporation method, so that the graphene and the gold film are perfectly laminated; and then the graphene/gold etched off the copper foil is moved to the D-type plastic optical fiber, so that the structure of the gold plus graphene is realized on the plastic optical fiber. The prepared SPR sensor made with the graphene/gold/D-type plastic optical fiber has the characteristic of a high recognition sensitivity of complementary and non-complementary DNA strands.

The invention provides a genetic chip and a detection kit related to major pathogenic microorganisms causing infectious diarrhea of human beings, which are mainly specific to 13 types of bacteria including lapactic bacillus coli/shigella, salmonella, comma bacillus, vibrio parahemolyticus, aeromona hydrophila, plesiomonas, virio hollisae, vibrio fluvialis, vibrio mimicus, Wauter's strains, vibriodamsela and vibrio furnissii. The genetic chip comprises a solid-phase carrier and an oligonucleotide probe fixed on the solid-phase carrier, wherein the oligonucleotide probe comprises DNA (Deoxyribonucleic Acid) fragments selected from genes including a gyrB gene, an ITS gene, a dnaJ gene, a toxR gene and the like with remarkable biological evolution advantages or complementary DNA fragments. By adopting the genetic chip and the detection kit provided by the invention, major pathogenic microorganisms causing infectious diarrhea of human beings can be detected. The genetic chip and the detection kit have the characteristics of easiness and convenience for operation, high flux, high accuracy, high repeatability and the like, and can be applied to clinical detection of inspection departments in hospitals.

The invention relates to a gene chip for detecting nine pathogenicity vibrios in marine products and a kit thereof. The gene chip comprises a solid phase carrier and an oligonucleotide probe, wherein the oligonucleotide probe includes one or more selected from the following nucleotide sequences: 1) DNA sequences selected from genes of a vibrio hollisae, a vibrio vulnificus, a vibrio cholera, a vibrio parahemolyticus, a vibrio harveyi, a vibrio alginolyticus, a vibrio furnissi, a vibrio mimicus and a vibrio damsel, 2) complementary DNA sequences of the DNA sequences selected in the DNA sequences in 1), 3) complementary RNA sequences of the selected DNA sequences in 1) or 2). The kit comprises the gene chips. The gene chip for detecting nine pathogenicity vibrios in marine products and the kit thereof provided by the invention are used for detecting the nine pathogenicity vibrios in marine products, and have the advantages of simplicity in operation, good sensitivity and strong repeatability.

The invention discloses a preparation method of a nanostar dimmer with surface raman strengthening activities and belongs to the technical field of materials chemistry. The method includes synthesizing gold seeds, synthesizing gold nanostars which modify deoxyribonucleic acid (DNA) 1 and DNA 2 respectively, and assembling gold nanostars modified by the DNA 1 and the DNA 2. The synthesized gold nanostars are plasma resonators and form a gold nanostar dimmer structure by means of coupling of complementary DNA chains. According to the method, self-assembly of the plasma gold nanostars is achieved, and the prepared gold nanostar dimmer is uniform in structure.