532 results about "Deoxyribose" patented technology

The invention belongs to the technical field of biology, and particularly relates to an extraction method of polydeoxyribonucleotide, which comprises the following steps: carrying out homogenate treatment on pretreated in-vitro testis tissue, filtering the obtained homogenate, adding a pancreas extract into the filtrate, and stirring to obtain enzymatic hydrolysate; and precipitating protein in the enzymatic hydrolysate, removing the protein, adding sodium acetate for treatment, adding absolute ethyl alcohol for precipitation, centrifuging, washing the obtained precipitate, and drying to obtain the product. Common trypsin and lipase in fish pancreas are beneficial to release of DNA, the fish pancreas extract is applied to extraction of the polydeoxyribonucleotide, the extraction time can be remarkably shortened, the yield can be increased, meanwhile, nuclease in the fish pancreas extract can effectively degrade DNA, and small-fragment polydeoxyribonucleotide is obtained.

The invention belongs to the technical field of biology, and particularly provides reverse transcriptase UCRT vZ mutants with improved thermal stability, the reverse transcriptase UCRT vZ mutants comprise four single-point mutants, six double mutants and four three mutants, and compared with wild type reverse transcriptase UCRT vZ, the half-life period of the mutants is longer at 65 DEG C; the double-mutant has a better effect, and the half-life period of the double-mutant is about four times that of the wild reverse transcriptase UCRT vZ. The invention also provides a genetically engineered bacterium containing the mutant. The reverse transcriptase UCRT vZ mutant obtained by the construction method provided by the invention has better thermal stability, shows higher thermal stability when being used for reverse transcription of RNA (Ribonucleic Acid) into cDNA (Complementary Deoxyribose Nucleic Acid) at a higher temperature, and has higher application potential.

The invention relates to bionic matrix hydrogel for constructing bone organs and a preparation method of the bionic matrix hydrogel. The bionic matrix hydrogel is prepared from a bone acellular extracellular matrix, a salmon DNA (Deoxyribose Nucleic Acid) network and a calcium phosphate oligomer under the combination of photo-crosslinking and self-assembly physical crosslinking. The acellular extracellular matrix in the bionic matrix hydrogel can simulate organic components in natural bones, the calcium phosphate oligomer can simulate inorganic components in the natural bones, and sufficient phosphate ions can be provided for biomineralization due to introduction of a DNA network. The biomimetic matrix hydrogel can replace Matrigel to act in bone organoid culture, provide a living environment similar to bone tissue for three-dimensional culture cells, enhance substance exchange and signal transduction between cells, promote proliferation, adhesion and osteogenic differentiation of bone marrow mesenchymal stem cells, and further accelerate the process of biomineralization. The invention provides an optional new material for preparing the functional bone organ.

The invention discloses a molecular marker closely linked with a wheat powdery mildew resistance gene PmL424. The molecular marker is YTU024-L10; the nucleotide sequence of an upstream primer of the molecular marker is as shown in SEQ ID NO: 1; the nucleotide sequence of the downstream primer is as shown in SEQ ID NO: 2; a marker primer of the molecular marker YTU024-L10 is used for carrying out PCR (Polymerase Chain Reaction) amplification on wheat genome DNA (Deoxyribose Nucleic Acid) to be detected to obtain a corresponding amplification product with the molecular weight of 238 bp, namely the molecular marker closely linked with the wheat powdery mildew resistance gene PmL424. The molecular marker provided by the invention can more accurately and efficiently detect a genetic mapping population of PmL424, and map-based cloning and fine positioning of PmL424 are facilitated; and secondly, the marker is used for molecular marker-assisted selection of PmL424, so that the wheat breeding cycle can be shortened, and the breeding efficiency can be improved.

The invention discloses a preparation method of polydeoxyribonucleotide, and relates to the technical field of synthetic biology, and the preparation method comprises the following steps: S1, randomly selecting n ssDNAs from a salmon genome sequence; s2, carrying out cyclization on the ssDNA, so as to obtain cssDNA; s3, carrying out amplification on the cssDNA to obtain a repeated long single-stranded DNA (Deoxyribose Nucleic Acid); and S4, breaking the repeated long single-stranded DNA to obtain the PDRN. According to the method, a large amount of repeated long single-stranded DNA can be synthesized only by introducing a small amount of foreign proteins (T4DNA ligase and Phi29 DNA polymerase), the repeated long single-stranded DNA is broken by a physical breaking method, and a large amount of PDRN products with ideal molecular weight can be obtained in a short time.

The invention relates to the technical field of polymer gels, and provides a multi-crosslinking composite gel and a preparation method and application thereof, the preparation method comprises the following steps: fully dissolving an activator in a buffer solution, and adjusting the pH value of the solution to 5.0-6.0 to obtain an activated solution; sequentially adding recombinant III-type humanized collagen, polydeoxyribonucleotide and chitosan into the activated solution, and uniformly dispersing to obtain a cross-linked precursor solution; adding a cross-linking agent into the cross-linking precursor solution, reacting for a period of time to obtain a cross-linking gel intermediate, and purifying to obtain the multi-cross-linking composite gel; the invention also provides the multi-crosslinking composite gel prepared by the preparation method, and application of the multi-crosslinking composite gel in the fields of beauty and plastic surgery. The material has biodegradability and good antibacterial performance, and can ensure slow release of the material and good filling effect and anti-enzymolysis effect at the same time.

The invention discloses a genetically engineered bacterium for producing uridine diphosphate glucose as well as a construction method and application of the genetically engineered bacterium, and belongs to the technical field of genetic engineering. The following genes are overexpressed in the genetically engineered bacterium: a pyrimidine nucleoside operon gene, a carbamyl phosphate synthetase gene, an aspartate carbamyl transaminase gene, an orotic acid phosphoribose transferase gene, a phosphoribose pyrophosphate synthase gene, a uridylate kinase gene and a glucophosphate mutase gene. A uridine triphosphate glucose-1-phosphate uridine group transferase gene; the genetically engineered bacterium does not express the following genes: a purine nucleotide repressor protein gene, a deoxyribonucleoside triphosphate reductase gene, a nucleoside triphosphate pyrophosphohydrolase gene, a cytidine triphosphate synthase gene, a pyrimidine nucleotidase gene, a nucleotidase gene, an ornithine carbamoyltransferase gene, a UDPG dehydrogenase gene and a lacI repressor protein gene. The genetically engineered bacterium can be used for efficiently synthesizing UDPG by taking glucose as a substrate.

The invention belongs to the technical field of gene engineering, and particularly relates to PDRN, a gene engineering vector, a cell, a preparation method and application thereof. The polydeoxyribonucleotide (PDRN) provided by the invention comprises a nucleotide sequence as shown in SEQ ID NO. 1; 1 or a partial fragment containing a nucleotide sequence shown in SEQ ID NO. 1; 1 or a sequence having 80% or more of homology with the nucleotide sequence as shown in SEQ ID NO. 1. The PDRN provided by the invention can effectively reduce and inhibit the expression level of inflammatory factors TNF-alpha and IL-6 and increase the wound healing rate of HUVEC cells, and is concentration-dependent. The PDRN provided by the invention has a good application prospect in preparation of anti-inflammatory or healing-promoting products.

The invention relates to a single nucleotide polymorphism (SNP) primer of a DSTN gene related to musk ketone content in natural musk and application of the single nucleotide polymorphism (SNP) primer, and belongs to the technical field of biological detection. The invention provides a single nucleotide polymorphism (SNP) primer of a DSTN gene related to the musk ketone content in natural musk, a molecular marker corresponding to the SNP primer is located at a 682371th basic group of a chromosome 23 of a forest musk deer reference genome, the basic group is mutated into A or C, the genotypes are AA and AC, and deoxyribonucleotide sequences of the SNP primer are shown as SEQ ID NO: 1 and SEQ ID NO: 2. According to a breeding target, by eliminating A / A genotype individuals and retaining A / C genotype individuals, the method has the beneficial effects that the relative content character of musk ketone in musk of the forest musk deer is efficiently and quickly identified, and a scientific basis is provided for early breeding of high-quality forest musk deer. The detection method disclosed by the invention is simple and easy to operate, can be carried out in a laboratory, and can also be applied to a genome breeding technology.

The invention provides a genetically engineered bacterium for producing O-succinyl-L-homoserine as well as a construction method and application of the genetically engineered bacterium. In a chassis bacterium genome, the expression of a 2-ketoglutaric acid decarboxylase encoding gene sucA is enhanced, and the expression of a succinyl-coenzyme A synthetase encoding gene sucD is weakened, so that the supply of succinyl-coenzyme A is increased; the method comprises the following steps: increasing the NADPH (Nicotinamide Adenine Dinucleotide Phosphate) reducing capacity and ATP (Adenosine Triphosphate) energy supply of a chassis bacterium, increasing DNA (Deoxyribose Nucleic Acid) in combination with a transcription dual regulatory factor ompR to improve the stress resistance of escherichia coli under high osmotic pressure, and introducing an overexpression plasmid containing a homoserine transsuccinylase coding gene metA to construct the genetically engineered bacterium for producing O-succinyl-L-homoserine. The engineering strain obtained through a systematic metabolic engineering modification strategy can realize effective accumulation of OSH, the shake flask yield of OSH reaches 19.8 g / L, the fed-batch fermentation yield of a 5L fermentation tank reaches 110.5 g / L, the sugar-acid conversion rate reaches 52.6%, and a foundation is laid for subsequent construction of high-yield OSH engineering bacteria.

The invention discloses an interpretable deep learning-based innate immune gene expression prediction method, which comprises the following steps of: 1, collecting and preprocessing a DNA (Deoxyribose Nucleic Acid) promoter sequence and epigenetic modification data, and dividing a preprocessed data set into a training set and an independent test set so as to verify the prediction performance of a model; 2, constructing a human innate immune gene expression prediction network based on residual connection, a convolutional neural network and an attention mechanism; 3, performing model training on a plurality of cell lines to obtain an optimal human innate immune gene expression prediction model, and evaluating the prediction effect of the model on the independent test set; and 4, carrying out post interpretability analysis on the model through an integral gradient method, and identifying a key motif which is most likely to influence gene expression. According to the method, DNA sequence information and epigenetic modification information are extracted more effectively, and a new tool is provided for deeply understanding a regulation mechanism of an innate immune gene and developing individualized medical treatment.

The invention relates to the technical field of biological detection, and discloses an in-situ detection method for the tissue level of a protein and phosphoinositide compound, which comprises the following steps: providing a to-be-detected tissue sample containing the protein and phosphoinositide compound; incubating the sample to be detected by using a primary antibody mixture; incubating a product obtained in the previous step by using a second antibody mixture containing a PLA probe, and reacting to obtain circular DNA (Deoxyribose Nucleic Acid); carrying out in-situ amplification by taking the circular DNA as a template; and acquiring and analyzing a signal of the detection probe. According to the method, the interaction between the protein and the phosphoinositide compound can be specifically detected in situ at the tissue level, the actual state of the protein and the phosphoinositide compound in the physiological and pathological processes of cells can be more truly reflected by the technology, and more accurate information is provided for researching the function and regulation mechanism of the protein and the phosphoinositide compound; wide application prospects are realized.

The invention belongs to the technical field of microorganisms, and relates to a riemerella anatipestifer phage and application thereof. The riemerella anatipestifer bacteriophage provided by the invention is RA-XHX1, is preserved in the China Center for Type Culture Collection (CCTCC), has the preservation number of CCTCC NO: M 20241268, and is classified and named as the riemerella anatipestifer bacteriophage. The bacteriophage is double-stranded DNA (Deoxyribose Nucleic Acid) and myuroviridae, can form transparent plaques on a solid culture medium, has no halo ring around and is clear and regular in edge; the bacteriophage has a relatively good killing effect on riemerella anatipestifer in a space environment, particularly high-pathogenicity riemerella anatipestifer, and can realize a broad-spectrum antibacterial effect when being applied to preparation of medicines for preventing and treating riemerella anatipestifer infection.

The invention discloses a correction method of PCR (Polymerase Chain Reaction) preference, a DNA (Deoxyribose Nucleic Acid) artificially synthesized sequence combination of a TCR-beta immune repertoire, a primer combination for amplifying the TCR-beta immune repertoire, a quantitative analysis method of the TCR-beta immune repertoire of a gDNA sample, a detection kit and application of the detection kit. The PCR preference correction method can effectively correct the preference generated in the PCR amplification process, the DNA artificially synthesized sequence combination can effectively adjust the primer concentration ratio of the multiple PCR primer combination, and the primer combination can efficiently and quantitatively amplify a TCR-beta immune repertoire without mutual interference as much as possible. According to the method, the immune repertoire can be accurately and quantitatively analyzed at the DNA level.

The invention relates to an SLC26A11 gene SNP (Single Nucleotide Polymorphism) primer related to androstenediol content in forest musk and application, and belongs to the technical field of biology. The invention provides an SLC26A11 gene SNP primer related to androstenediol content in moschus berezovskii, a molecular marker corresponding to the SNP primer is located at the 55966787 base of chromosome 21 of a moschus berezovskii reference genome, the base is mutated into A or G, the genotypes are AG and GG, and deoxyribonucleotide sequences of the SNP primer are shown as SEQ ID NO: 1 and SEQ ID NO: 2. The detection method disclosed by the invention is simple and easy to operate, can be carried out in a laboratory, and can also be applied to a genome breeding technology. The method has the beneficial effects that the relative content character of androstenediol in the forest musk deer can be efficiently and quickly identified, and a scientific basis is provided for early breeding of high-quality forest musk deer.

The invention provides a sphingomonas paucimobilis CRISPRi / dCas12a gene regulation system as well as a construction method and application thereof, and particularly belongs to the technical field of gene engineering. The gene regulation and control system disclosed by the invention comprises a pBBR1-dCas12a-crRNA plasmid, wherein the plasmid comprises a pBBR1 replicon, a dCas12a gene, a crRNA expression cassette and a chloramphenicol resistance gene; the crRNA expression cassette comprises a Ptac promoter, two DR fragments and an rrnB T1 terminator, and is characterized in that the crRNA expression cassette comprises a Ptac promoter, two DR fragments and an rrnB T1 terminator. The system disclosed by the invention can stably express in sphingomonas paucimobilis and inhibit the transcription of genes so as to reduce the expression of specific genes without modifying the DNA (Deoxyribose Nucleic Acid) sequence of the specific genes, has lower toxicity to S.paucimobilis, is high in host growth speed and can realize the efficient expression of dcas12a.

The invention belongs to the field of application of microbial genetic engineering and metabolic engineering, and particularly relates to a method for improving the biosynthesis efficiency of sclareol. Specifically, in a host strain, gene knockout is realized through a CRISPR / Cas9 technology, or / and a DNA fragment is introduced, and a strain metabolic pathway is adjusted to obtain a corresponding engineering strain; carrying out biosynthesis by utilizing the obtained engineering strain to obtain sclareol; the gene knockout is realized by introducing donor DNA (Deoxyribose Nucleic Acid) containing upstream and downstream homologous arms of a coding frame; the DNA fragment sequentially comprises an upstream homologous arm, a promoter, a gene, a terminator and a downstream homologous arm from upstream to downstream, the host strain is selected from any one of saccharomyces cerevisiae. According to the method, the cell life is associated with product synthesis, and meanwhile, metabolic balance is coupled, so that the synthesis efficiency of a target product is improved, and a foundation is laid for industrial fed-batch fermentation.

The invention discloses a detection method and application of whole genome 5-hydroxymethylcytosine, and relates to the technical field of biochemical detection. Comprising the following steps: 1, closing a 3 '-OH end of DNA to be detected; 2, preparation of glycosylated 5hmC DNA (Deoxyribose Nucleic Acid); 3, carrying out TdT mediated DNA (Deoxyribonucleic Acid) amplification; and 4, fluorescence measurement. According to the invention, a homogeneous and non-template dependent type signal amplification method for detecting the 5-hydroxymethylcytosine in the whole genome is constructed. The method is based on a specific enzyme catalytic reaction and a multiple signal amplification strategy, and has the characteristics of high sensitivity, good specificity, no need of a separation step, no sequence dependence in amplification and capability of detecting 5hmC at any position in a whole genome. In addition, accurate and sensitive detection of actual clinical samples can be realized.

The invention belongs to the technical field of microbiological detection, and discloses a composite probe for detecting salmonella enteritidis and a preparation method. The composite probe for detecting the salmonella enteritidis comprises magnetic nanoparticles FeO, wherein the surface of the magnetic nanoparticles FeO is modified with an aptamer apt which is specifically combined with the salmonella enteritidis; the surface of the long afterglow nano particle PLNPs is modified with a DNA (Deoxyribose Nucleic Acid) sequence cDNA (Complementary Deoxyribonucleic Acid) complementary with the aptamer; the aptamer apt and the complementary DNA sequence cDNA are subjected to hybridization to form a composite probe structure FeO-SEapt (at) PLNPs-cDNA (complementary deoxyribonucleic acid). The long afterglow luminescence characteristic of PLNPs (ZnGaO: Cr) is utilized, and an excitation light source is stopped before detection, so that signal acquisition completely avoids autofluorescence of a sample matrix, background fluorescence interference is thoroughly eliminated, and the signal-to-noise ratio is remarkably improved.

The invention belongs to the technical field of biology, and particularly provides reverse transcriptase UCRT vL mutants with improved thermal stability, the reverse transcriptase UCRT vL mutants comprise four single-point mutants, six double mutants and four three mutants, and compared with wild type reverse transcriptase UCRT vL, the half-life period of the mutants is longer at 65 DEG C; the three mutants are better in effect, and the half-life period of the three mutants is about three times that of the wild type reverse transcriptase UCRT. The invention also provides a genetically engineered bacterium containing the mutant. The reverse transcriptase UCRT vL mutant obtained by the construction method provided by the invention has better thermal stability, shows higher thermal stability when being used for reverse transcription of RNA (Ribonucleic Acid) into cDNA (Complementary Deoxyribose Nucleic Acid) at higher temperature, and has higher application potential.

The invention relates to the technical field of biotechnology, and discloses a special biological fresh-keeping preservative method for cattle stomach, which comprises the following steps: firstly, pretreating the cattle stomach; the method comprises the following steps: putting the cattle stomach into flowing clear water, washing off obvious impurities, dirt and mucous membrane liquid on the surface, soaking the cattle stomach in saline water or a food-grade cleaning agent solution in a certain proportion for 10-30 minutes, kneading the surface of the cattle stomach, washing the kneaded cattle stomach with clear water again, and removing impurities and cleaning agent residues after soaking and kneading, and placing the cleaned cattle stomach in a filter screen or a clean container, and naturally draining water. And further determining the strain by adopting a 16SrDNA (Deoxyribose Nucleic Acid) detection technology, and analyzing experimental data to find out a bacteriostatic agent with the best effect and the lowest effective bacteriostatic concentration through a bacteriostatic activity experiment. And finally, determining quality index data of the cattle stomach through a single factor and an orthogonal test, and optimizing the bacteriostatic agent with the best effect, so that the shelf life of the cattle stomach stored at low temperature is prolonged.

The invention relates to the technical field of biomedicine, in particular to a method for constructing a plasma ctDNA organ distribution characteristic spectrum of advanced colorectal cancer. The method comprises the following steps: collecting a peripheral blood sample at multiple time points, separating plasma by adopting a double-centrifugal method, and extracting circulating tumor DNA (Deoxyribose Nucleic Acid); carrying out whole exome sequencing based on ctDNA to obtain genome variation information and calculating variation allele frequency, and synchronously detecting the expression quantity of immune-related proteins by adopting an Olink proteomics technology; integrating the genome data, the protein expression data and the clinical pathological features, and constructing a multi-dimensional feature data matrix; and taking the organ metastasis condition confirmed by iconography as a supervision label, training a model by applying a machine learning algorithm, screening key prediction factors, constructing a quantitative prediction model, and finally generating a visual organ metastasis tendency prediction map. According to the method, early and accurate prediction of the advanced colorectal cancer organ metastasis tendency is realized through multi-omics data collaborative analysis and machine learning modeling.

The invention discloses an SNP (Single Nucleotide Polymorphism) molecular marker combination for constructing a hazel DNA (Deoxyribose Nucleic Acid) fingerprint spectrum and application thereof. The SNP molecular marker combination comprises 50 SNP molecular markers, can be applied to construction of the hazel plant DNA fingerprint spectrum and further applied to variety identification of hazel plants, fills the blank of the hazel plant SNP molecular markers and the hazel plant DNA fingerprint spectrum based on the SNP molecular markers, and can be used for identifying the hazel plant variety by utilizing DNA fingerprint spectrum information of different hazel varieties. The method can accurately and efficiently distinguish and identify the germplasm resources of the hazel plants, and is of great significance to development and protection of the germplasm resources of the hazel plants.

The invention provides a polyethylene glycol derivative-collagen cartilage repair gel which is characterized by being prepared from the following components in parts by weight: 8 to 12 parts of collagen (namely COL) solution, 0.5 to 2 parts of polydeoxyribonucleotide (namely PDRN), 4 to 8 parts of polyethylene glycol disuccinimide succinate (namely SS-PEG-SS) solution and 0.1 to 0.4 part of tannic acid (namely TA), and particularly discloses a preparation method and application of the polyethylene glycol derivative-collagen cartilage repair gel. In a word, the composite gel and the collagen are subjected to efficient amidation reaction through SS-PEG-SS to form a stable three-dimensional network, so that the structural support of the type I collagen, the tissue repair of PDRN and the anti-inflammatory and anti-oxidation characteristics of tannic acid are successfully integrated; therefore, the composite material has the comprehensive performance of good structural stability, high mechanical strength, good biocompatibility, controllable degradation period, excellent needle passing performance and the like, and shows the wide application prospects of clear repair effect, remarkable component synergistic effect, mature production process, outstanding cost effectiveness and the like.

The invention discloses extraction of polydeoxyribonucleotide as well as preparation and application of a PDRN-Ce (Polydeoxyribonucleotide-Ce) microsphere cluster. The extraction and purification method comprises the following steps: mixing in-vitro fish testis tissues with water, carrying out crushing treatment and homogenization treatment on an obtained premix, carrying out proteolysis and solid-liquid separation, and collecting supernate to obtain enzymatic hydrolysate; wherein protease used for proteolysis comprises neutral protease; carrying out alcohol precipitation on the enzymatic hydrolysate by adopting an alcohol solvent, and collecting a precipitate; and dissolving the precipitate in water, desalting and drying. According to the extraction method, the purity and the yield of the poly-deoxyribonucleotide are remarkably improved, the preparation method is low in cost and convenient to operate, the prepared poly-deoxyribonucleotide is stable in property, small in molecular weight and easy to absorb by skin, in order to further improve the bioavailability of the extracted poly-deoxyribonucleotide, the PDRN-Ce microsphere cluster is prepared, and the PDRN-Ce microsphere cluster can be used for preparing the poly-deoxyribonucleotide. Good application prospects are realized.

The present invention relates to CpG oligodeoxyribonucleotides with improved body immunity, combinations thereof with additional adjuvants, and uses of the CpG adjuvants or combinations thereof in various vaccine compositions. The CpG independently serves as an adjuvant or is combined with an existing marketed adjuvant for use, and the CpG has the very remarkable advantages that the immune effect is advanced, the immune effect is improved, the lasting period of the immune protection effect is longer, the potential anaphylactic reaction is lower and the like, is superior to a commercially available vaccine adjuvant or an adjuvant system, and is a very excellent effective component of the vaccine adjuvant or the vaccine adjuvant system.

The invention discloses a molecular marker closely linked with a wheat powdery mildew resistance gene PmCWI16926. The molecular marker is YTU2BS-P12, and the molecular marker is a molecular marker PmCWI16926. The nucleotide sequence of an upstream primer of the molecular marker is as shown in SEQ ID NO: 1; the nucleotide sequence of the downstream primer is as shown in SEQ ID NO: 2; the molecular marker is used for carrying out PCR (Polymerase Chain Reaction) amplification on to-be-detected wheat genome DNA (Deoxyribose Nucleic Acid) to obtain a corresponding amplification product with the molecular weight According to the molecular marker YTU2BS-P12 closely linked with the wheat powdery mildew resistance gene PmCWI16926, provided by the invention, a genetic mapping group of the PmCWI16926 can be more efficiently detected, and map-based cloning of the PmCWI16926 is facilitated; when the marker is used for molecular marker-assisted selection of PmCWI16926, the breeding period can be shortened, the breeding efficiency can be improved, and the marker can be better applied to wheat breeding for disease resistance.

The invention relates to the technical field of non-replicative adenovirus vectors, in particular to a primer combination and a method for detecting residual DNA fragments in an E1 region of a host cell of a non-replicative adenovirus vector. The primer combination comprises an E1A primer pair and an E1B primer pair, the E1A primer pair comprises a first primer as shown in SEQ ID NO. 1 and a second primer as shown in SEQ ID NO. 2, and the E1B primer pair comprises a third primer as shown in SEQ ID NO. 3 and a fourth primer as shown in SEQ ID NO. 4. The primer combination can be used for carrying out specific detection on E1 residual fragments in HEK293 cell host DNA (Deoxyribose Nucleic Acid); the detection method has the advantages of high efficiency, good effect, high specificity, good sensitivity and good repeatability.

The invention provides an MWCNTs-Au electrochemical biosensor based on RPA-CRISPR as well as a preparation method and application of the MWCNTs-Au electrochemical biosensor, and belongs to the technical field of preparation of electrochemical biosensors and detection of pathogenic bacteria of dairy products. The electrochemical biosensor disclosed by the invention comprises a multi-walled carbon nanotube-nanogold-hairpin nucleotide probe modified silk-screen printing carbon electrode and a CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-crRNA-Target DNA (Deoxyribose Nucleic Acid) ternary complex, the CRISPR-crRNA-Target DNA ternary complex is assembled on the surface of the multi-walled carbon nanotube-nanogold-hairpin nucleotide probe modified silk-screen printing carbon electrode, and the CRISPR-crRNA-Target DNA ternary complex is assembled on the surface of the multi-walled carbon nanotube-nanogold-hairpin nucleotide probe The electrochemical biosensor shows wide linear response in a range of 1.04 * 10 < 1 > to 1.04 * 10 < 8 > CFU / mL, and the detection limit is as low as 3 CFU / mL; and the method has good practicability in detection of staphylococcus aureus.

The invention provides a preparation method and application of a high-activity salmon salmon sperm PDRN (DNA sodium) raw material. The preparation method comprises the following steps: crushing and freezing a salmon testis at an ultralow temperature, adding a mixed solution of a Tris-HCl buffer solution and sodium chloride, and dispersing at a low temperature; adding a compound enzyme preparation with the total enzyme activity of more than or equal to 350KU / L, and carrying out low-temperature appropriate pH enzymolysis; and adjusting the pH value to a suitable range, and carrying out frequency conversion ultrasonic and high-pressure homogenization alternate synergistic treatment in an ice-water bath to obtain the DNA fragmentation liquid, so that the defects of low PDRN activity retention rate, insufficient purity and high protein residue in the prior art are overcome.