279 results about "Molecular cloning" patented technology

The present invention provides compositions, methods, and kits for covalently linking nucleic acid molecules. The methods include a strand invasion step, and the compositions and kits are useful for performing such methods. For example, a method of covalently linking double stranded (ds) nucleic acid molecules can include contacting a first ds nucleic acid molecule, which has a topoisomerase linked to a 3′ terminus of one end and has a single stranded 5′ overhang at the same end, with a second ds nucleic acid molecule having a blunt end, such that the 5′ overhang can hybridize to a complementary sequence of the blunt end of the second nucleic acid molecule, and the topoisomerase can covalently link the ds nucleic acid molecules. The methods are simpler and more efficient than previous methods for covalently linking nucleic acid sequences, and the compositions and kits facilitate practicing the methods, including methods of directionally linking two or more ds nucleic acid molecules.

Methods and compositions for cloning a donor DNA molecule into an acceptor vector at a predetermined location are described. The methods are based on homologous recombination mediated by in vitro treatment of the donor DNA and the acceptor vector with an enzyme cocktail containing an exonuclease and a single-stranded DNA binding protein.

The invention relates to the molecular cloning and expression of a gibberellin (GA) 20-oxidase gene and its use, for example in transgenic plants. Aspects of the invention include recombinant DNA which encodes a polypeptide exhibiting GA 20-oxidase activity, a recombinant polypeptide exhibiting GA 20-oxidase activity, and transgenic plants which express a GA 20-oxidase gene or reverse GA 20-oxidase sequences.

The invention relates to the molecular cloning and expression of a gibberellin (GA) 20-oxidase gene and its use, for example in transgenic plants. Aspects of the invention include recombinant DNA which encodes a polypeptide exhibiting GA 20-oxidase activity, a recombinant polypeptide exhibiting GA 20-oxidase activity, and transgenic plants which express a GA 20-oxidase gene or reverse GA 20-oxidase sequences.

The invention discloses an application of a growth factor series mediated by an active factor Tat protein transcribed by an immunodeficiency virus (HIV-1) in the transdermal transfer, in particular to an application in the fields of transdermal administration and cosmetics. The application is achieved by the following steps of: constructing a fusion protein recombinant expression vector of Tat and a series of active proteins in the growth factor family by the general molecule clone method, purifying with different chromatographic columns to obtain a fusion protein, or linking the Tat to a natural or synthetic phosphatide by the chemical and (or) physical method to prepare a liposome coating the growth factor, forming a transdermal transfer system for the Tat-mediated liposome, matching with proper pharmaceutical or cosmetic auxiliary materials to prepare finished products used for a transdermal administration system or a cosmetics system. The invention can effectively transfer the active proteins of the growth factor with macromolecules through the skin by the Tat mediation and fully exert the effect. The invention provides a novel platform to the application of Tat.

The invention provides a method for preparing a molecular cloning chip by cloning high flux nucleic acid molecule. The method comprises the following steps: a. a cloning nucleic acid molecule template is mixed with a nucleic acid amplification reaction system reagent to obtain an amplification mixture solution; b. the amplification mixture solution is added with a high molecular compound; c. the solution is added with oil phase, of which the volume is two times of the volume of the solution for emulsification to obtain water-in-oil emulsion; d. the emulsion is placed in a PCR meter or a thermostat to undergo a nucleic acid amplification reaction; e. after the nucleic acid amplification reaction, the emulsion is cooled down to form nucleic acid molecule cloning grains; f. the nucleic acid molecule cloning grains are separated; and g. the nucleic acid molecule cloning grains are randomly dispersed on a solid phase carrier to fix the nucleic acid amplification products in the solution onthe solid phase carrier and form a nucleic acid molecule cloning array on the surface of the solid phase carrier and thus the cloning chip is obtained. The method has the advantages of improving preparation sequencing template, ensuring high flux of sequencing and lowering sequencing cost.

Objective of the present invention is to provide a method for keeping of directional information in double-stranded DNA. We suggest to convert polynucleotide into a hybrid double-stranded DNA. One particular strand of this hybrid double-stranded DNA should be synthesized using at least one modified nucleotide. Thus, this particular strand would contain modified nucleotides along the whole length. Density of directional markers would not depend on the length of polynucleotides. Any internal fragments of the hybrid double-stranded DNA would have directional information. When it is necessary the modified strand may be easily degraded or separated from the other strand. It was found that such hybrid double-stranded DNA may be easily generated in a number of molecular biology tasks and may be used for molecular cloning, library preparation and strand separation.

The invention provides a nucleic acid molecular cloning method based on homologous recombination. According to the method provided by the invention, a target DNA is cloned to a vector by the homologous recombination through providing a linearizing vector with two ends respectively added with sequences(namely specific homologous arm of the target DNA) homologous with sequences at the two ends of the target DNA or the flanking sequence of the target DNA or utilizing a connecting section containing the specific homologous arm of the target DNA as well as the specific homologous arm of the vector (sequence homologous with the specific region of the vector). The nucleic acid molecular cloning method provided by the invention is especially suitable for the clone of large DNA section and polymorphism researches of mononucleotide. The invention further provides a related kit.

A substituted Norovirus capsid protein monomer, having only the P-domain and called an antigen-Norovirus P-domain monomer, includes a foreign antigen inserted into one or more of three surface loops present on each P-domain monomer by molecular cloning. The antigen-P-domain monomer can assemble spontaneously into an octahedral form, called an antigen-Norovirus P-particle, that is composed of 24 copies of the antigen-P-domain monomer. Each substituted P-domain monomer will contain one to three copies of the foreign antigen, for a total of 24-72 antigen copies on each antigen-P-particle. The antigen-P-particle is useful in methods for diagnosing, immunizing and treating individuals infected with a foreign virus, for example Rotavirus, and can serve as a carrier for presentation of foreign antigens for development of novel vaccines against many infectious and non-infectious diseases. The substituted Norovirus P-particles can be readily produced in E. coli and yeast, are highly stable and tolerate a wide range of physio-chemical conditions. A modified Norovirus P-domain monomer includes one or more restriction recognition sites inserted within one or more of the three loops of the P-domain monomers, to provide user-friendly cloning cassettes for conveniently inserting candidate foreign antigens into the surface loops. The P-particle-VP8 chimeras may also serve as a dual vaccine against both rotavirus and norovirus.