68 results about "Protease K" patented technology

The invention discloses a method for preparing PDRN with different molecular weights and application of the method. Salmonidae testis are taken, protamine cells are subjected to enzymolysis through protease K, enzymatic hydrolysate is pretreated through ultrasonic waves, a pretreated sample is subjected to DNaseI enzymolysis, and therefore PDRN with the target molecular weight is obtained. According to the method, the problem of single molecular weight of PDRN in the prior art is solved, and products with different molecular weight ranges can be accurately prepared by combining ultrasonic treatment with DNaseI enzymolysis, namely changing the power and time of ultrasonic treatment and the enzyme amount and enzymolysis time of DNaseI; the molecular weight range can be concentrated in 500-1000 bp, 1000-2000 bp and 2000-4000 bp, the situation that the molecular weight range is wide and fragments are not concentrated is effectively avoided, the product specification is relatively concentrated, and the method is suitable for industrial application.

The invention provides a gene extraction method for AAV third-generation sequencing, and particularly provides a simple and efficient rAAV gene extraction method for third-generation sequencing, which comprises the following steps: firstly, performing shell breaking on rAAV purified virus by using protease K to obtain an initial reaction solution; performing alkali denaturation on the initial reaction solution, neutralizing, purifying by using a DNA product purification kit, and eluting by using nuclease-free water to obtain denatured virus genome DNA; and finally, incubating and annealing the denatured virus genome DNA to finally form the complete double-stranded DNA. Compared with a traditional AAV genome extraction method, the method provided by the invention is simpler and more efficient, and the extracted DNA is higher in integrity.

The invention discloses an IV-type collagen detection kit and a preparation method thereof, and relates to the technical field of in vitro diagnos.The kit comprises a reagent R1 and a reagent R2, and the volume ratio of the reagent R1 to the reagent R2 is 3: 1; through an elaborately designed reagent formula, especially the accurate proportion of all components in the reagent R1, such as ammonium chloride, sodium azide and Brij-35, the detection sensitivity and accuracy are improved, the stability and repeatability of the kit are also ensured, and particularly, the natural plant extract astragalus polysaccharide and the protease K inhibitor are introduced into the reagent R1 as key components, so that the detection sensitivity and accuracy are improved, and the detection sensitivity and repeatability are improved. According to the present invention, the unique preparation method and the activity promotion effect on the IV-type collagen hydrolase significantly enhance the biological activity of the kit, such that the detection result is reliable, and the two latex particles coated with the paired mouse monoclonal antibodies adopted in the reagent R2 have high specificity and affinity, such that the kit can be used for the detection of the IV-type collagen hydrolase. And the detection accuracy and sensitivity are further improved.

The invention provides a cfDNA extraction kit and an extraction method. The cfDNA extraction kit provided by the invention comprises protease K, a lysis buffer solution, magnetic beads and a binding buffer solution, by limiting the composition of the lysis buffer solution and the binding buffer solution, not only can the extraction efficiency of cfDNA be effectively improved, but also the purity of the cfDNA can be remarkably improved, the cfDNA of 100-200 bp can be effectively enriched, and the kit is convenient in component acquisition, low in cost and suitable for industrial production. Meanwhile, the extraction operation is simple and suitable for high-throughput treatment.

The invention discloses low-endotoxin macromolecule PDRN, a preparation method and application. A freeze-dried white powder sample is obtained through fish testis pretreatment, fish sperm cell enzymolysis, deproteinization, ultrasonic pretreatment, nuclease enzymolysis, primary alcohol precipitation, redissolution and filtration, endotoxin control, secondary alcohol precipitation, alcohol washing and freeze-drying. Fragmentation is carried out by combining ultrasonic waves with nuclease enzymolysis, the use amount of enzyme can be effectively reduced, the molecular weight of the product can be accurately controlled, operation is easy, and the industrialization cost is low. The method comprises the following steps: carrying out enzymolysis on protamine cells through protease K, releasing protamine DNA, carrying out fragmentation on a PDRN sample by using ultrasonic waves and nuclease, and carrying out deep filtration and triton 114 washing to obtain the protamine with the molecular weight controllable interval of 500bp-4000bp; the content of endotoxin is less than or equal to 0.5 EU / mg, and the content of protein is less than or equal to 1.0%. The finished product is obtained by freeze-drying the PDRN wet solid, and the quality and the additional value of the product are improved.

The invention relates to a colorimetric detection method for Tween-20 in a protein preparation, which comprises the following steps: diluting the protein preparation with a diluent for enzymolysis, carrying out chromogenic reaction by using dichloromethane and an ammonium iron thiocyanate system, and measuring absorbance by using a visible spectrophotometer. The diluent is composed of other components except protein and Tween 20 in the protein preparation; an enzyme used in the enzymolysis is protease K; the concentration of the protease K is preferably 200 mu g / ml; the enzymolysis temperature is preferably 55-57 DEG C; the enzymolysis time is preferably 3.5 to 4 hours.

The invention relates to the technical field of nucleic acid extraction, in particular to a nucleic acid extraction method and a nucleic acid extraction kit. The nucleic acid extraction kit can remove protein in a sample and further release / purify nucleic acid. According to the nucleic acid extraction method, the protease K is added in the washing liquid of the extraction reagent, protein which is deeply combined can be treated, nucleic acid is further released, high-temperature dissociation is used in the nucleic acid elution process, the protease K is inactivated, and the influence on subsequent amplification is avoided.

The invention relates to the technical field of molecular diagnosis, in particular to a high-sensitivity peripheral blood free DNA magnetic bead capture system, a methylation transformation method kit and application. The kit is composed of a lysis solution, a protease K diluent, a composite conversion reagent, a washing solution, a scavenger, an eluent and combined magnetic beads. According to the high-sensitivity peripheral blood free DNA magnetic bead capture system and the methylation transformation method kit, the detection limit of early-stage lung cancer ctDNA reaches 0.005% AF, the I-stage cancer ctDNA detection rate is increased to 93% from the industry average 40%, the sample size is reduced to 4 mL from the conventional 10 mL, the batch-to-batch difference of the kit is small, and the kit has very high application value clinically.

The invention discloses a kit for rapidly purifying viral nucleic acid from different types of liquid biological samples and an extraction method. The kit comprises the following reagents: a lysis binding solution, a protease k solution, magnetic beads, a washing solution I, a washing solution II and an eluent. When the kit is used for extracting the viral nucleic acid, the three steps of protease K digestion, lysate lysis and nucleic acid combination are simultaneously carried out, the operation steps are greatly simplified, the extraction time of the viral nucleic acid is shortened, and the obtained high-quality viral nucleic acid can be directly applied to downstream experiments such as PCR (Polymerase Chain Reaction), RT-PCR (Reverse Transcription-Polymerase Chain Reaction), qPCR (Quantitative Polymerase Chain Reaction) and the like.

The invention relates to the field of cosmetic compositions, in particular to a cosmetic composition containing triple polishing enzyme and a preparation method of the cosmetic composition. The triple polishing enzyme comprises protease, protease K and superoxide dismutase, the weight part ratio of the protease to the protease K to the superoxide dismutase is 1: (0.5-2): (0.5-2), the total mass percent of the triple polishing enzyme in the composition is 0.0002%-0.001%, and the invention further discloses a preparation method of the cosmetic composition. A triple polishing enzyme synergistic system is formed through scientific compounding, the integrated skin care effect under low concentration is achieved, and the defects of a traditional chemical stripping agent and the shortages of a single enzyme preparation are overcome; meanwhile, by optimizing the proportion of formula components, the composition forms a liquid crystal structure, so that long-acting dual moisturizing of internal water locking and external water sealing is realized, triple polishing enzyme can be wrapped and protected, and the problems that the composition is easy to oxidize and inactivate and low in transdermal efficiency are solved.

The invention discloses a method for efficiently extracting genome DNA (Deoxyribose Nucleic Acid) of ophiurocephalus serratus. The method comprises the following steps: mixing a sample with a lysis solution and metal balls, crushing the mixture at-20 to-10 DEG C for 250-350s at 40-60Hz, and placing the crushed sample at-20 to 4 DEG C; cracking the sample at the temperature of 50-60 DEG C for 4-6 minutes; centrifuging at 2-4 DEG C, taking a supernatant, adding an extraction agent, and uniformly mixing; centrifuging at 2-4 DEG C, taking an upper-layer solution, adding an extracting agent, and uniformly mixing; centrifuging at 2-4 DEG C, taking an upper-layer solution, adding isopropanol, uniformly mixing, and standing at-20--15 DEG C for 20-30 minutes; centrifuging at 2-4 DEG C, discarding the supernatant, washing the precipitate with an ethanol solution, and dissolving with an eluent; the lysis solution contains CTAB (Cetyltrimethyl Ammonium Bromide), protease K and beta-mercaptoethanol. According to the invention, the problem of high-mineralization echinodermis sample treatment is solved, and a high-quality nucleic acid template and a new technology are provided for research on ocean invertebrate genetics.

The invention belongs to the technical field of biology, and relates to a narrow-spectrum antibacterial peptide XMK-8 and application thereof. The amino acid sequence of the narrow-spectrum antibacterial peptide XMK-8 is as shown in SEQ ID NO: 1, and the narrow-spectrum antibacterial peptide XMK-8 has no bacteriostatic activity on escherichia coli, salmonella, staphylococcus aureus and aeromonas hydrophila and only has bacteriostatic activity on pasteurella multocida and haemophilus parasuis. The antibacterial activity of the narrow-spectrum antibacterial peptide XMK-8 can still be detected after treatment with salt ions (sodium ions and potassium ions, 50-200 mmol / L), acid-base (pH 4-10) and protease K (20-100 [mu] g / mL) at the temperature of 0-100 DEG C, and the narrow-spectrum antibacterial peptide XMK-8 has low hemolytic activity on red blood cells of mice. The antibacterial peptide XMK-8 disclosed by the invention is expected to become a novel antibiotic substitute and has a good application prospect in prevention, treatment, diagnosis and identification of pasteurella multocida, haemophilus parasuis and infection thereof.

The invention discloses a method for detecting methylation level of heterozygous heterologous DNA (deoxyribonucleic acid) in saccharomyces cerevisiae. Comprising the following steps: preparing a saccharomyces cerevisiae genome, carrying out enzymolysis on the saccharomyces cerevisiae genome, and detecting the methylation level of heterozygous heterologous DNA in saccharomyces cerevisiae by using an ultra-high performance liquid chromatography-triple quadrupole mass spectrometer. According to the method, saccharomyces cerevisiae cell walls can be better removed, the use time of protease K is adjusted, protein combined with DNA molecules is better removed, saccharomyces cerevisiae genomes are extracted with high quality, and impurities are greatly reduced; the PMSF protease inhibitor is added in the saccharomyces cerevisiae genome extraction process, so that the activity of protease K can be effectively inhibited, the residual protease K is prevented from degrading nuclease and other key enzymes in the subsequent DNA enzymolysis process, and the DNA enzymolysis efficiency is improved. The method can be directly applied to DNA methylation detection of saccharomyces cerevisiae.

The invention relates to the field of DNA extraction of leather cultural relics, and discloses a method for extracting cattle genomes from vegetable tanned cattle leather cultural relics. The method comprises the following steps: after cleaning the vegetable tanned cow leather cultural relics, dehydrating, freeze-drying and grinding and crushing with liquid nitrogen; metal ions are chelated through an EDTA-Tris detanning reagent to destroy a tannin structure, so that the wrapping on DNA (Deoxyribose Nucleic Acid) is reduced; then, lysate and protease K are used for lysis and digestion, cell membranes are damaged, protein is degraded, and DNA is released; adding absolute ethyl alcohol to precipitate and separate out DNA; and finally, purifying, recovering and purifying the DNA through an adsorption column. The genome DNA extracted by the method is large in fragment, high in purity and stable and reliable in quality.

The application provides a polypeptide with angiotensin converting enzyme inhibitory activity and a preparation method and application thereof, and relates to the technical field of active peptide preparation. The abalone is pulverized, a complex enzyme is added for primary enzymolysis, and then a specific protease mixture containing prolyl endopeptidase, chymotrypsin and protease K is added for two-step enzymolysis, so that the obtained polypeptide solution has high ACE inhibitory activity. The obtained polypeptide is analyzed and screened to obtain polypeptides with amino acid sequences as shown in SEQ ID NO. 1-5. The polypeptide has high ACE inhibitory activity, and the IC 50 0.05mg / mL-0.40mg / mL, and therefore can play a blood pressure lowering effect as an angiotensin converting enzyme inhibitor.

The invention provides a preparation method of a nucleic acid detection sample, which comprises the following steps: adding a pH response type hydrogel into an inactivated virus preservation solution, mixing, applying the inactivated virus preservation solution to virus sample collection to obtain a sample solution, applying the inactivated virus preservation solution to a nucleic acid detection sample, and detecting the nucleic acid detection sample according to the sample solution, the pH response range of the pH response type hydrogel is 5-6, and the pH value of the inactivated virus preservation solution is 7.5-8. Adding protease K and magnetic beads into the sample solution, uniformly mixing, performing enzymolysis, adjusting the pH value to 5-6, incubating for 10-30 minutes, centrifuging a container filled with the sample solution, fixing the magnetic beads at the bottom of the container through a magnet, removing supernate, washing the magnetic beads at least once, and drying the washed magnetic beads to obtain a sample solution; and eluting the washed magnetic beads to obtain the nucleic acid detection sample. According to the preparation method, a nucleic acid detection sample with higher nucleic acid content can be obtained, so that the accuracy of nucleic acid detection is improved.

The invention discloses a plasma free DNA extraction reagent, a kit and an extraction method, the extraction reagent comprises protease K, a lysis solution, a binding solution, a washing solution 1, a washing solution 2, a washing solution 3 and an eluent, the extraction reagents contain more common and less-dosage common reagents such as Tris-HCl (pH 8.0), EDTA.2Na. 2H2O, NaCl, glycerol, SDS, isopropanol, ethanol, Tween-20 and the like. The method has the advantages that the problems that the reagent is easy to separate out and needs to be heated and redissolved for use during storage can be solved without traditional high-concentration guanidine salts such as guanidine hydrochloride and guanidinium isothiocyanate, the stability and the operation convenience of the extraction reagent are increased, a better extraction effect is achieved, and the eluent can effectively protect the extracted cfDNA from being degraded.

The invention provides a magnetic bead method liquid sample pathogenic microorganism nucleic acid extraction kit, which is characterized by comprising protease K, a nucleic acid protection solution, a lysis strengthening solution, a lysis binding solution, magnetic beads MXVB, a washing solution 1, a washing solution 2 and an eluent, wherein the cracking combination liquid is prepared from tris (hydroxymethyl) aminomethane, guanidine isothiocyanate, ammonium thiocyanate, tween-80, lauryl sodium sulfate, sodium chloride and isopropanol; the nucleic acid protection liquid comprises tris (hydroxymethyl) aminomethane hydrochloride and formamide; the cracking reinforcing liquid is lauryl sodium sulfate. According to the kit, DNA of bacteria, fungi and viruses can be rapidly extracted and purified, the extraction efficiency of pathogenic microorganism nucleic acid is improved, good stability is achieved, the nucleic acid quality is guaranteed, and development of a pathogenic microorganism detection technology is facilitated.

The invention belongs to the technical field of food detection, and particularly relates to a detection method for determining the form of trace selenium in vegetables in a geological high background area. The method comprises the following steps: cleaning a vegetable sample, freeze-drying, grinding and crushing, adding a specific compound enzyme system (protease XIV, protease K and cellulase) and a Tris-HCl buffer solution, performing water bath ultrasonic treatment, performing constant-temperature oscillation for enzymolysis, performing low-temperature centrifugation on an extracting solution for multiple times, and filtering and purifying the extracting solution by a microporous filter membrane, the method comprises the following steps: detecting the selenium form of a sample by adopting a high performance liquid chromatograph and inductively coupled plasma mass spectrometer serial device, and quantitatively analyzing tetravalent selenium (Se4 +), hexavalent selenium (Se6 +), selenomethionine (SeMet), methylselenocysteine (SeMeCys) and selenocystine (SeCys2) in the sample by adopting a normalization method. The detection method disclosed by the invention is strong in anti-interference capability and high in sensitivity, and original form information can be completely reserved.

The invention belongs to the technical field of nucleic acid extraction, and particularly relates to a large-volume sample free nucleic acid extraction kit, a nucleic acid extraction method and a detection method. The kit comprises a lysis solution, a protease K solution, a binding solution, a rinsing solution 1, a rinsing solution 2, an eluent and magnetic beads. The nucleic acid extraction method comprises the following steps: centrifuging a sample by adopting the kit, splitting and incubating; leaving the magnetic beads, and rinsing the magnetic beads with a rinsing liquid 1 and a rinsing liquid 2 for three times respectively; eluting with an eluent, and collecting to obtain a nucleic acid solution. The nucleic acid extraction method and the kit are applied to an automatic workstation, and reagents are added into different hole sites; and the program is operated after the reagent is added. The detection method comprises the following steps: determining the total amount of extracted DNA of the nucleic acid solution, the quality of extracted nucleic acid and the recovery efficiency of the nucleic acid solution. The invention provides a kit capable of being stored at normal temperature, a plurality of nucleic acid extraction methods and a detection method, can be used for free nucleic acid extraction, quality evaluation and large-scale nucleic acid extraction of a large-volume sample, and is low in detection cost and high in efficiency.

The invention discloses a plant RNA extraction method, and belongs to the technical field of RNA extraction. The extraction method of the plant RNA comprises the following steps: mixing plant tissue powder, a CTAB lysate, a sulfydryl reducing agent and protease K, and then cracking at 60-65 DEG C to obtain a lysate; centrifuging the lysate, taking a supernatant, mixing the supernatant with a first solvent, oscillating, and washing the supernatant to obtain a precipitate; the precipitate and nuclease-free water are mixed and dissolved, and then DNase I and Buffer RDD are added for incubation; continuously adding sodium acetate, an RNA extraction phenol reagent and a second solvent, oscillating, carrying out ice bath, and centrifuging to obtain supernate; carrying out isopropanol precipitation on the supernate to obtain plant RNA (Ribonucleic Acid); the first solvent or the second solvent is a mixture of chloroform and isoamyl alcohol. According to the extraction method provided by the invention, the purpose of completely digesting the genome DNA is achieved on the premise of not influencing the quality of extracted RNA.

The invention relates to an immunofluorescence method and kit for detecting zebra fish heart DNA methylation level, and belongs to the technical field of biological detection. The immunofluorescence method provided by the invention comprises the following steps: exposing a zebrafish embryo to a substance to be detected, dissecting a heart sample of the zebrafish embryo and carrying out fixation, membrane permeation, protease K digestion, hydrochloric acid DNA denaturation and neutralization treatment, and then carrying out sealing, incubation of a 5-methylcytosine primary antibody and a fluorescently labeled secondary antibody, cell nucleus staining and fluorescence detection. And finally, analyzing and evaluating the DNA methylation level through fluorescence imaging. According to the method disclosed by the invention, through a combined step of protease K and hydrochloric acid denaturation treatment, the binding efficiency to the antibody is remarkably improved, so that high-sensitivity and low-background detection on the methylation level of the whole DNA in a zebra fish micro heart sample is realized; the detection kit provided by the invention can be widely applied to epigenetics evaluation of toxicity of environmental pollutants.

The invention provides a polypeptide with angiotensin converting enzyme inhibition as well as a preparation method and application thereof, and relates to the technical field of active peptide preparation. According to the method, the abalone is crushed, the compound enzyme is added for primary enzymolysis, then the specific protease mixture containing prolyl endopeptidase, chymotrypsin and protease K is added for secondary enzymolysis, and the obtained polypeptide liquid has high ACE (angiotensin converting enzyme) inhibition. The obtained polypeptide is analyzed and screened to obtain the polypeptide with the amino acid sequence as shown in SEQ ID NO.1-5. The polypeptide disclosed by the invention has high ACE (angiotensin converting enzyme) inhibition, and IC50 (50% of IC50) of the polypeptide to ACE is 0.05 mg / mL-0. 40mg / mL, so that the polypeptide can be used as an angiotensin converting enzyme inhibitor to play a role in reducing blood pressure.

The application discloses a DNA / RNA reagent kit based on a magnetic bead method and free of enzyme digestion, and belongs to the technical field of nucleic acid extraction and purification. The reagent kit comprises a lysis solution AL, protease K, a specific binding buffer CLB, amino magnetic bead suspension, silicon hydroxyl magnetic bead suspension and other components. The application solves the problems of nucleic acid degradation, incomplete removal of cross contamination and complicated process caused by enzyme digestion in the prior art, is suitable for automatic high-throughput processing, and has a wide application prospect in scientific research and clinical application.

The invention discloses a method for separating, screening and identifying staphylococcus in a chick embryo sample, which comprises the following steps: S1, sterilizing collected chick embryo tissues, cutting into pieces, mixing with an SCB liquid culture medium, and culturing in a shaking table to obtain a culture solution; s2, scribing the obtained culture solution into a BP (Back Propagation) culture plate, putting the plate into an incubator for standing culture, after monoclone grows out of a culture dish, picking the monoclone, and uniformly blowing and beating the monoclone in PBS (Phosphate Buffer Solution) to obtain a mixed bacteria solution; s3, incubating the obtained mixed bacteria solution in lysostaphin to obtain a mixed solution I; s4, Tris-HCl and protease K are added into the obtained mixed solution I, incubation is conducted firstly, then heating is conducted, and a mixed solution II is obtained; and S5, carrying out PCR amplification by taking the obtained mixed solution II as a template to obtain a product, and identifying. The method is accurate, rapid, economical and efficient.

The invention belongs to the technical field of biomedical detection, and particularly relates to a lysis solution for candida albicans, a kit and a gene detection method. The cleavage efficiency and background interference are balanced by regulating and controlling the concentration of saponin, nucleic acid can be wrapped by too many saponin micelles, and cleavage is incomplete if too few saponin micelles exist; citric acid buffers to adjust the acidic environment, although RNA degradation may be promoted, nuclease is cleared through high-salt rapid cracking and protease K, and negative effects are counteracted; the pre-activated protease K is synchronous with membrane rupture, so that the enzyme activity peak is matched with the exposure time of the target protein, the degradation efficiency is improved, and a cracking technology which can simultaneously realize high-yield and high-function nucleic acid output and is adaptive to a rapid detection process is developed.

The invention belongs to the technical field of molecular detection, and discloses a nucleic acid hybridization capture immunofluorescence detection kit as well as a use method and application thereof. In the kit provided by the invention, guanidine hydrochloride, guanidine isothiocyanate, triton X-100, NaCl, protease K and lauryl sodium sulfate are compounded according to a specific concentration to obtain the nucleic acid release liquid, so that pathogen nucleic acid in a clinical sample can be fully dissociated, and the nucleic acid release liquid can cooperate with a probe aiming at a specific target pathogen; the solution system can be used for optimizing the recognition and combination process of DNA and RNA, the specific recognition and combination capacity between the probe and specific pathogen nucleotide is improved, and under the condition that a common nucleic acid stabilizer, namely Tween, is not contained, the solution system can further strengthen differential structural epitopes existing in a DNA / RNA complex compared with DNA and RNA, so that the specificity of the DNA / RNA complex is improved, and the specificity of the DNA / RNA complex is improved. The kit can be better recognized and combined by an anti-DNA / RNA complex antibody, and has excellent detection specificity, sensitivity and precision.

The invention relates to a protective agent, a sample collection protection card as well as a preparation method and application of the sample collection protection card. The protective agent is prepared from the following components: a buffer agent, SDS (Sodium Dodecyl Sulfate), octyl glucoside, Pluronic F-127, polysaccharide, a complexing agent, protease K, an antioxidant and an antimicrobial agent. The sample collection protection card containing the protective agent can effectively preserve trace cell samples, so that subsequent accurate and effective detection of genetic materials carried by single cells is facilitated.

The application discloses a marine organism muscle tissue DNA extraction kit and application thereof, and belongs to the technical field of biological detection. The extraction kit comprises a lysis solution, a first washing solution and a second washing solution. The lysis solution is composed of Triton x-100 45 mM, Tris-HCl 10 mM, EDTA-Na 80 mM, NaCl 80 mM and Brij-35 3 mM, and has a pH of 8.3. The first washing solution is composed of 70% ethanol solution containing 200 mM Tris-HCl. The second washing solution is composed of 80% ethanol solution. The marine organisms include oceanic fishes, Antarctic fishes, shellfishes, crabs and shrimps. The tissue is taken, cut, mixed with the lysis solution and protease K, and uniformly mixed in a water bath. The application is based on the phenol extraction method, and various mild reagents are mixed to realize rapid and accurate DNA extraction, so that the purity, quality and integrity of the DNA are ensured.

The invention discloses a method for extracting oligonucleotides from fresh animal medicines and the oligonucleotides obtained by the method. The extraction method comprises: enzymolyzing the fresh medicines with a mixed enzyme of trypsin and proteinase K to obtain enzymolyzates; then grading by ultrafiltration to collect the part with a molecular weight cutoff of 3kDa to 30kDa; finally, subjecting the ultrafiltrate to anion exchange column chromatography, washing away unbound impurities and eluting with an eluent to obtain the oligonucleotides from the fresh animal medicines. The extraction method is based on the pharmacology and medicinal components of the fresh medicines, and adopts the method of enzymolysis, ultrafiltration and ion exchange chromatography to retain and enrich the medicinal active components as much as possible, and well avoids the oligonucleotides from being degraded by nucleases.