119 results about "DNA - Deoxyribonucleic acid" patented technology

The invention discloses applications of a CRISPR/Cpf1 system in gene editing. CrRNA in the CRISPR/Cpf1 system is modified crRNA; the modification manner is desoxyribonucleic acid modification; the desoxyribonucleic acid modification method comprises the step of increasing 1-3 desoxyribonucleic acid at the 5' terminal and/or increasing 1-3 desoxyribonucleic acid at the 3' terminal of crRNA; and the desoxyribonucleic acid is deoxythymidine acid. The experiment proves that the crRNA formed through chemical synthesis and having the modification can cause the mutation of an hAAVS1 gene and a THUMPD3-AS1 gene when used for the AsCRISPR/Cpf1 system or the FnCRISPR/Cpf1 system, namely, the modified crRNA has certain gene editing capacity when used for the AsCRISPR/Cpf1 system or the FnCRISPR/Cpf1 system, and therefore, the modified crRNA has a significant application value in gene editing utilizing the CRISPR/Cpf1 system.

The invention relates to a construction method of a human amniotic mesenchymal stem cell bank. The construction method comprises the following steps: taking a human amnion for detection, flushing and washing the human amnion with a phosphate buffered solution, then smashing the human amnion, diluting with the phosphate buffered solution, digesting with trypsin, digesting with collagenase IV and deoxyribonuclease I, and filtering to obtain a single-cell suspension; by adding human serum albumin, transferring, insulin and sodium selenite into a DMEM/F12 basal culture medium with the ratio of VDMEM to VF12 being 1 to 1, placing human amnion mesenchymal stem cells in an incubator under the serum-free condition, and then performing liquid exchange and culture transfer; subjecting the mesenchymal stem cells obtained through in vitro culture and proliferation to liquid nitrogen refrigeration, and preserving the cells according to the gender of newborn infants, the ABO/Rh type and the HLA type; establishing cell information files, so that the human amniotic mesenchymal stem cell bank is constructed. The method has the characteristics of no other animal derivation, wide source range and no ethic limitation. With adoption of the method, the human amniotic mesenchymal stem cells can be provided for cell therapy and other application.

The invention discloses an electrochemical sensor for detecting lead and a preparation method and application of the electrochemical sensor. The electrochemical sensor comprises a glassy carbon electrode, a signal amplifying device, a response probe and a target probe, wherein the surface of the detecting end of the glassy carbon electrode ismodified by ordered mesoporous carbon, and gold nanoparticles are deposited on the ordered mesoporous carbon; a hydrosulfuryl-modified capture probe is adsorbed on gold nanoparticles; the signal amplifying device includes the ordered mesoporous carbon with gold nanoparticles being deposited; methylene blue is adsorbed on the ordered mesoporous carbon with gold nanoparticles being deposited; the response probe is adsorbed on the gold nanoparticles of the signal amplifying device through hydrosulfuryl; the nucleotide sequence of the response probe is nucleotide sequence of chimera of deoxyribonucleic acid and nucleotide adenosine. The preparation method of the electrochemical sensor includes the steps of modifying the glassy carbon electrode, preparing the glassy carbon electrode and preparing the response probe and target probe solution. The electrochemical sensor provided by the invention can be used for detecting the lead ions in water, and has the advantages that the operation is simplified, the response is quick, and the sensitivity, the detection accuracy and the anti-jamming property are high.

The invention belongs to the biomedical field, discloses a double-stranded asymmetric small nucleic-acid-interference-molecule asiRNA inhibiting a tumour apoptosis suppressor specifically and an application thereof. The asiRNA is designed by a following method and obtained by chemical synthesis, starting from a Bcl 2 gene symmetry small nucleic-acid-interference-molecule siRNA, by cutting 1-5 nt base off a 5 ' end or a 3 ' end of an siRNA sense strand or an siRNA antisense strand, and forming the double-stranded asymmetric small nucleic-acid-interference-molecule asiRNA wherein base lengths are different and the 3' end of each strand is equipped with two deoxyribonucleic acids dTdT in a single strand suspension and RNA interference can be induced, by using two nucleotides with abutting deoxyribonucleic acid dTdT on the 3' end of each strand. The asiRNA of the invention is more stable than the routine siRNA, activity to inhibit expression of Bcl 2 is stronger, and can be applied in antitumor drug preparation.

The invention belongs to a cell DNA detection technology and in particular relates to a method for detecting 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 2'-deoxyguanosin (dG) in cell DNA. The method can be used for quantitatively detecting the change of the content of 8-OHdG and dG in cell DNA, caused by exposure of harmful ingredients in cigarette smoke, so that the purpose of evaluating DNA oxidation damage caused by induction of the harmful ingredients can be achieved. According to the method, deoxyribonuclease I and alkaline phosphatase are used for hydrolyzing DNA in a cell, and deferoxamine mesylate is added into enzymatic hydrolysate, so that the oxidation of dG in the enzymolysis process is avoided; enzymatic hydrolysate is detected by HPLC-MS/MS; the cell DNA oxidation damage degree is evaluated according to the value of 8-OHdG/10<6>dG. By virtue of the method, the interference of high-concentration metal ions and artificial dG oxidation is removed, and thus the result is relatively accurate; the method is low in detection limit, high in sensitivity, good in repeatability and high in recovery rate.

The invention relates to a culture and cryopreservation method of amniotic mesenchymal stem cells. The culture method comprises amniotic tissue separation, amniotic mesenchymal stem cell separation, P0 generation amniotic mesenchymal stem cell culture and amplification culture. According to the culture method of the amniotic mesenchymal stem cells, at a separating stage of the amniotic mesenchymalstem cells, a special mixed enzyme digestive juice system (the final concentrations of components in the digestive juice are as follows: 1.5-2U/mL of neutral protease, 0.5mg/mL of deoxyribonuclease Iand 1mg/mL of collagenase IV) is adopted for digestion, so that the amniotic mesenchymal stem cells can be more effectively separated from amniotic tissues, and then the yield of P0 generation cellsis obviously improved. Compared with conventional two-step digestion, the culture method provided by the invention has the advantages that a one-step digestion method is adopted, operation is more convenient, and the cultured amniotic mesenchymal stem cells have good activity, high yield, high purity and good repeatability.

The invention relates to a preparation method of levodopa nanoparticles and biosensing application of the levodopa nanoparticles, and belongs to the technical field of nano biosensing. Levodopa (L-DA)is used as a unique precursor to synthesize levodopa nanoparticles (LNDS) at room temperature, and the formed LNDS can quickly and effectively quench a dye-labeled oligonucleotide fluorescent probe (FAM-DNA) through electrostatic interaction. Complementary deoxyribonucleic acid (cDNA) or adenosine triphosphate (ATP) is competitively combined with a fluorescent probe, so that fluorescence is recovered, and an effective sensing platform for detecting biomolecules is constructed. In addition, the sensing platform can also perform high-sensitivity and selective detection on adenosine triphosphatein a complex system (human serum). The synthetic process of the levodopa nanoparticles is simple and environmentally friendly, the toxic and side effects on cells and organisms are low, the levodopananoparticles have a very strong quenching effect on dye-labeled oligonucleotides, the background fluorescence is greatly reduced, and the signal-to-noise ratio is increased.

The present invention discloses a deoxyribonucleic acid extraction device during a nucleic acid detection process. The deoxyribonucleic acid extraction device comprises a base seat, a stirring assembly is arranged at a top part of the base seat, the stirring assembly comprises a measuring cylinder, a rubber sleeve, a plastic cylinder, a glass rod, a circular plate, a rubber tube, curved rods, first supports, compression springs, curved plates, supporting rods, first pin shafts, first handles and hooks. The deoxyribonucleic acid extraction device during the nucleic acid detection process is simple in whole operation flow and high in work efficiency. Beneficial effects are as follows: through cooperation between the glass rod, the circular plate, a servo motor, the curved plates, the compression springs, the curved rods and a clamping rod, the deoxyribonucleic acid extraction device can realize automatic stirring at a uniform speed for a long time of cell sap, greatly reduces labor amount of operating personnel, guarantees that cell walls in the cell sap can be damaged completely, releases whole deoxyribonucleic acid, can avoid problems of glass rod rupture and measuring cylinder toppling while improving operating efficiency, and guarantees normal extraction work.

In order to simply obtain a methylated DNA sample, a method including bringing a sample which may include methylated DNA into contact with a protein capable of binding to methylated DNA to bind the methylated DNA in the sample to the protein, bringing the sample obtained into contact with at least one deoxyribonuclease to degrade DNA in the sample; and detecting methylated DNA which is not degraded by the deoxyribonuclease by the binding of the sample obtained to the protein is used. In the method, at least one type of deoxyribonucleases is a deoxyribonuclease different from a methylation-sensitive restriction enzyme capable of degradating a single stranded DNA.