4 results about "Lambda exonuclease" patented technology

A genome-wide R-loop detection method, in particular, a genome-wide R-loop detection method independent of affinity enrichment and a use. According to the genome-wide R-loop detection method, nucleases are used to perform enzyme digestion on genomic DNA fragments, and R-loop detection can be achieved by performing one-step enzyme digestion simply using a system of Nuclease P1, T5 exonuclease, and Lambda exonuclease. The whole R-loop detection process does not require affinity enrichment or labeling treatment. The method is not only simple and easy to operate, but also can avoid the loss of samples and fragments, thereby reducing the cost and risk of detection, and improving the applicability.

The application discloses a homogeneous fluorescence quantitative detection method for base deletion sites in genomic DNA sequences, and covalently labels known sequence oligonucleotide chains to the base deletion sites through a covalent connection reaction, and realizes quantitative detection of the base deletion sites in the genomic DNA sequences by using Lambda exonuclease and corresponding fluorescence probes. The application is simple in operation, high in sensitivity, small in required biological sample amount, and can conveniently, quickly, sensitively and accurately determine the content of the base deletion sites in biological samples, and has high application value in biomedical research, clinical diagnosis and drug development evaluation related to DNA damage and repair.

The application discloses a double-stranded nucleic acid detection composition based on lambda exonuclease and deoxyribozyme and application thereof, and belongs to the technical field of biological technology, and aims to efficiently and sensitively detect double-stranded nucleic acid. The double-stranded nucleic acid detection composition based on lambda exonuclease and deoxyribozyme comprises a double-stranded nucleic acid detection probe, lambda exonuclease and a reporter molecule, the double-stranded nucleic acid detection probe comprises one long single-stranded DNA named recognition chain R and n short single-stranded DNAs named Dz; the recognition chain R comprises a target binding domain and n Dz binding domains arranged in sequence from 5' to 3' in order; the 5' end of the recognition chain R is modified with a functional group; the Dz is a deoxyribozyme capable of cleaving the reporter molecule when the Dz is single-stranded, and the 5' end of the Dz is modified with sulfur. The application has high sensitivity and specificity, and the detection limit can be as low as a femtomole.

A method, which synthesizes closed circular single-stranded and double-stranded DNA molecules using in vitro enzymatic systems, is described. Circular single-stranded DNA molecules and double-stranded DNA molecules (e.g., relaxed, or supercoiled) with various sizes can be synthesized. Unwanted DNA molecules, e.g., unligated oligomers, can be removed by exonucleases, such as T5 exonuclease, T7 exonuclease, lambda exonuclease, E. coli exonuclease I and / or III. A method of converting the single-stranded circular DNA molecules into double-stranded circular DNA molecules is also described. The single-stranded and double-stranded circular DNA molecules can be used in a variety of applications.