40 results about "Dna targeting" patented technology

A method for engineering and utilizing large DNA vectors to target, via homologous recombination, and modify, in any desirable fashion, endogenous genes and chromosomal loci in eukaryotic cells. These large DNA targeting vectors for eukaryotic cells, termed LTVECs, are derived from fragments of cloned genomic DNA larger than those typically used by other approaches intended to perform homologous targeting in eukaryotic cells. Also provided is a rapid and convenient method of detecting eukaryotic cells in which the LTVEC has correctly targeted and modified the desired endogenous gene(s) or chromosomal locus (loci) as well as the use of these cells to generate organisms bearing the genetic modification.

The present invention refers to methods for selectively recognizing a base pair in a DNA sequence by a polypeptide, to modified polypeptides which specifically recognize one or more base pairs in a DNA sequence and, to DNA which is modified so that it can be specifically recognized by a polypeptide and to uses of the polypeptide and DNA in specific DNA targeting as well as to methods of modulating expression of target genes in a cell.

The present invention refers to methods for selectively recognizing a base pair in a DNA sequence by a polypeptide, to modified polypeptides which specifically recognize one or more base pairs in a DNA sequence and, to DNA which is modified so that it can be specifically recognized by a polypeptide and to uses of the polypeptide and DNA in specific DNA targeting as well as to methods of modulating expression of target genes in a cell.

The invention discloses a novel gene editing system which is established based on gene cas3 of an I-B type CRISPR-Cas system in a chromosome of Virginia streptomycete IBL14, the gene editing of an I type CRISPR-Cas system to a biological cell genome is realized for the first time, and new supplement and choice are provided for the gene editing system which is established by II type commercializedCas9. In the system, a target DNA can be specifically cut by the Cas3 through crRNA guide or t-DNA location. By adopting the system, error-free, simple and rapid gene editing can be performed on prokaryotic and eukaryotic genomes. The optimized gene editing system is expected to be superior to the commercialized gene editing system which is established based on Cas9 in multiple fields due to low molecular weight and ability to be guided by DNA.

The present invention provides a Cas9 platform to facilitate single-site nuclease gene editing precision within a human genome. For example, a Cas9 nuclease/DNA-targeting unit (Cas9-DTU) fusion protein precisely delivers a Cas9/sgRNA complex to a specific target site within the genome for subsequent sgRNA-dependent cleavage of an adjacent target sequence. Alternatively, attenuating Cas9 binding using mutations to the a protospacer adjacent motif (PAM) recognition domain makes Cas9 target site recognition dependent on the associated DTU, all while retaining Cas9's sgRNA-mediated DNA cleavage fidelity. Cas9-DTU fusion proteins have improved target site binding precision, greater nuclease activity, and a broader sequence targeting range than standard Cas9 systems. Existing Cas9 or sgRNA variants (e.g., truncated sgRNAs (tru-gRNAs), nickases and FokI fusions) are compatible with these improvements to further reduce off-target cleavage. A robust, broadly applicable strategy is disclosed to impart Cas9 genome-editing systems with the single-genomic-site accuracy needed for safe, effective clinical application.

The invention discloses a preparation method of a DNA (Deoxyribonucleic Acid) targeting nano medicine-carrying molecule for a brain tumor. The preparation method comprises the steps that a DNA single strand is added to a Tris-MgCl solution and mixed, and reacts to form a DNA tetrahedron solution; the DNA tetrahedron solution and a targeting peptide solution are added to a mixed solution of a PBS (Phosphoric acid solution), a CuSO4 solution, a TCEP (Tris-(2-carboxyethyl)-phosphine) solution and a TBTA (Tert-Butyl 2,2,2-trichloroacetimidate) solution, and subjected to thermostatic reaction; a targeting DNA tetrahedron solution is obtained; a tumor medicine is added to the targeting DNA tetrahedron solution; constant temperature oscillation, centrifugation, and supernatant removal are conducted; and an obtained sediment is the DNA targeting nano medicine-carrying molecule. According to the preparation method, peptide molecules having specificity in the tumor are modified on DNA tetrahedrons via a point-and-click reaction, so that construction of a targeting DNA nano-carrier is realized; and the targeting DNA medicine-carrying molecule has extremely high specific recognition function, low cytotoxicity and good structural stability.

A series of new chemical agents that demonstrate anti-tumor activity are described. The new chemical agents combine two major mechanisms of anti-tumor action. In an embodiment, the agents are capable of both inhibiting EGFR and damaging DNA while also, upon degradation, degrading to an inhibitor of EGFR and to an agent capable of damaging DNA. Moreover, a novel series of molecules capable of releasing two moles of EGFR inhibitor and a potent bi-functional alkylating agent are also described.

The method to induce monocular DNA directed mutation by atomic force microscope in biotechnology field comprises steps shown follow: (1) preparing mica substrate modified by aminosilane; (2) labelling the end of DNA sample; (3) straightening and preparing the labelled sample; (4) inducing mutation; (5) collecting and separating the induced DNA segment; (6) amplifying monocell; (7) detecting amplification by agarose gel electrophoresis; (8) sequenching sample DNA, and screening the mutated sample. The advantages of this invention include: precise location, high resolution, high efficiency, and simple operation.

The invention discloses a primer group and a kit for nucleic acid detection of SARS-CoV-2 virus and application of the primer group and the kit. The primer group for an N gene and an ORF1ab gene of the SARS-CoV-2 virus is designed, and the kit comprises the primer group, guide DNA targeting a target gene, a molecular beacon with a fluorescent marker and PfAgo enzyme. The primer group provided by the invention can be used for simply and quickly amplifying new coronavirus nucleic acid, and has the characteristics of good repeatability, high sensitivity and strong specificity.

The present invention relates to a polypeptide comprising at least one at least one deletion selected from the group consisting of ΔHNH (Δ775-909), ARuvCIII-b (Δ1002-1074), AREC1-a (Δ510-655), AREC1-b (Δ525-587), AREC1-c (Δ662-710), AREC2 (Δ180-308), AREC2-a (Δ212-244), AREC2-b (Δ244-276), AREC2-c (Δ276-308), AREC2-d (Δ199-283), AREC2-e (Δ198-257), AREC2-f (Δ235-286), AREC2-g (Δ217-266), AREC3 (Δ498-712) and combinations thereof, wherein the position numbering is in accordance with SEQ ID NO: 1 encoding for S. pyogenes Cas9, and wherein the polypeptide has CRISPR-Cas DNA-binding activity. The polypeptide may further comprises a missense mutations selected from G12R, T13K, T13R, N14K, N497K, T657K, T657R, N767K, T770K, T770R, Q920K, Q920R, S1109R, D1135K, D1135R, S1338R and combinations thereof. Also claimed are nucleic acid molecules encoding for said polypeptides, compositions and method of site-directed engineering of a target DNA thereof.

The invention discloses a fusion protein based on CjCas9 and VPR core structure domains, a corresponding DNA targeting activation system and application of the system. The fusion protein comprises twoheterologous polypeptide structure domains, and one polypeptide structure domain comprises VPR protein with the transcription activation activity; the other polypeptide structure domain comprises theCjCas9 protein, the CjCas9 protein is in a dCjCas9 subtype or a mini-dCjCas9 subtype or a CjCas9 wild type, and the dCjCas9 subtype contains D8A and H559A single-locus amino acid mutation; the mini-dCjCas9 subtype contains D8A single-locus amino acid mutation and deficiency of most HNH structure domains. The DNA targeting activation system comprises the fusion protein and one or more kinds of guide RNA, and the guide RNA comprises a sequence with the length of 14-22 bp and a framework sequence with the length of 80 bp, wherein the sequences are designed for a target gene promoter area. The DNA targeting activation system is applied to targeting activation of a gene. The DNA targeting activation system has the advantages of being small in size, capable of achieving high specificity, a highactivation effect and easy synthesis, low in cost and the like.

Kits and a method for cleaving double-stranded DNA using Ref and RecA protein and variants thereof at a site having a DNA sequence homologous to the sequence on a single-stranded DNA targeting fragment are disclosed.

The present invention provides a variant Staphylococcus aureus Cas9 (SaCas9) protein having an altered specificity for a prototype spacer adjacent motif (PAM) sequence. The present invention also relates to CRISPR/Cas9 systems and methods for altering the genomic DNA sequence using the variant SaCas9 protein. Also disclosed are methods of producing variant Cas9 proteins with altered PAM specificity.