Abstract: An objective of the present invention is to establish a technique for making it possible to immobilize an enzyme on an electrically conductive base material in a uniformly, high density, and constantly aligned orientation, for the purpose of constructing an enzyme electrode having improved electrode performance. An electrode having enzyme crystals immobilized thereon, the electrode being provided with an electrically conductive base material that can be connected to an external circuit and enzyme crystals that serve as an electrode catalyst, wherein the enzyme crystals are immobilized on the electrically conducive base material; a method for producing an electrode having enzyme crystals immobilized thereon; and a biological fuel cell and a biosensor which are provided with an electrode having enzyme crystals immobilized thereon.

Abstract: An objective of the present invention is to establish a technique for making it possible to immobilize an enzyme on an electrically conductive base material in a uniformly, high density, and constantly aligned orientation, for the purpose of constructing an enzyme electrode having improved electrode performance. An electrode having enzyme crystals immobilized thereon, the electrode being provided with an electrically conductive base material that can be connected to an external circuit and enzyme crystals that serve as an electrode catalyst, wherein the enzyme crystals are immobilized on the electrically conducive base material; a method for producing an electrode having enzyme crystals immobilized thereon; and a biological fuel cell and a biosensor which are provided with an electrode having enzyme crystals immobilized thereon.

Abstract: The invention establishes a technology that allows non-specific amplification to be inhibited during nucleic acid amplification in an isothermal amplification reaction, such that the amplification efficiency is increased. The invention is a extreme thermophile single-stranded DNA binding mutant protein, having an amino acid sequence that expresses a function that can contribute to increasing an amplification efficiency of a template nucleic acid in an isothermal amplification reaction system that uses a strand displacement polymerase, and having in its amino acid sequence a mutation site where a mutation involving at least one of deletion, substitution, addition, and insertion of one or more amino acids in amino acid sequence of extreme thermophile single-stranded DNA binding protein has occurred, and a method of use thereof.

Abstract: A heat-stable RecA mutant protein is obtained by mutation involving either deletion or substitution of at least one amino acid in an amino acid sequence composing an acid region at C-terminal end of a wild type heat-stable RecA protein, and has an improved ability, compared to the wild type heat-stable RecA protein, for contributing to an increase in an amplification specificity of a template nucleic acid in a nucleic acid amplification reaction.

Abstract: An object of the present invention is to provide a nucleic acid amplification method for amplifying a desired nucleic acid while suppressing amplification of byproducts in a PCR reaction, a reagent kit used for nucleic acid amplification, a method of detecting single nucleotide polymorphism to detect single nucleotide polymorphism by utilizing that amplification of byproducts is suppressed in a PCR reaction, and a reagent kit used for detecting single nucleotide polymorphism. The method of amplifying nucleic acids by PCR is characterized by admixing in a reaction solution, a homologous recombinant protein which contains at least one of a RecA protein derived from Thermus thermophilus, and a modified RecA protein obtained by modification of the RecA protein and having a function similar to that of the RecA protein, and carrying out PCR.

Abstract: The present invention is to provide a method which makes it possible to activate RecA, and maintain its biological function in all the PCR cycles. Also, the invention is to provide a nucleic acid amplification method, and a kit for amplifying a nucleic acid which makes it possible to suppress non-specific amplification more specifically and efficiently to amplify only the desired nucleic acid. A method of activating a RecA protein derived from an extremely thermophilic bacterium in a polymerase chain reaction carried out in the presence of the RecA protein derived from the extremely thermophilic bacterium, wherein the RecA protein is activated by carrying out the reaction with the addition of nucleotide 5?-triphosphate (provided that the nucleotide 5?-triphosphate is neither deoxynucleotide 5?-triphosphate nor nucleotide 5?-O-3-thiotriphosphate).

Abstract: An object of the present invention is to provide a nucleic acid amplification method for amplifying a desired nucleic acid while suppressing amplification of byproducts in a PCR reaction, a reagent kit used for nucleic acid amplification, a method of detecting single nucleotide polymorphism to detect single nucleotide polymorphism by utilizing that amplification of byproducts is suppressed in a PCR reaction, and a reagent kit used for detecting single nucleotide polymorphism. The method of amplifying nucleic acids by PCR is characterized by admixing in a reaction solution, a homologous recombinant protein which contains at least one of a RecA protein derived from Thermus thermophilus, and a modified RecA protein obtained by modification of the RecA protein and having a function similar to that of the RecA protein, and carrying out PCR.

Abstract: The invention establishes a technology that allows non-specific amplification to be inhibited during nucleic acid amplification in an isothermal amplification reaction, such that the amplification efficiency is increased. The invention is a extreme thermophile single-stranded DNA binding mutant protein, having an amino acid sequence that expresses a function that can contribute to increasing an amplification efficiency of a template nucleic acid in an isothermal amplification reaction system that uses a strand displacement polymerase, and having in its amino acid sequence a mutation site where a mutation involving at least one of deletion, substitution, addition, and insertion of one or more amino acids in amino acid sequence of extreme thermophile single-stranded DNA binding protein has occurred, and a method of use thereof.

Abstract: The present invention is to provide a method which makes it possible to activate RecA, and maintain its biological function in all the PCR cycles. Also, the invention is to provide a nucleic acid amplification method, and a kit for amplifying a nucleic acid which makes it possible to suppress non-specific amplification more specifically and efficiently to amplify only the desired nucleic acid. A method of activating a RecA protein derived from an extremely thermophilic bacterium in a polymerase chain reaction carried out in the presence of the RecA protein derived from the extremely thermophilic bacterium, wherein the RecA protein is activated by carrying out the reaction with the addition of nucleotide 5?-triphosphate (provided that the nucleotide 5?-triphosphate is neither deoxynucleotide 5?-triphosphate nor nucleotide 5?-O-3-thiotriphosphate).

Abstract: This invention is to provide a nucleic acid recombination method which enables to carry out precisely homologous recombination of a desired target region, a host cell which enables to carry out precisely homologous recombination of a desired target region, and an expression vector which can be used for the nucleic acid recombination method and the host cell. The nucleic acid recombination method to carry out homologous recombination of a nucleic acid in a host cell employs a host cell which enables the expression and recombination of a RecA-like protein, and enables the expression of a RecX-like protein. And, the nucleic acid recombination method comprises a recombination step of a nucleic acid to carry out homologous recombination of the nucleic acid by the RecA-like protein expressed in the host cell, and a RecA inhibition step to inhibit the activity of the RecA-like protein by expressing the RecX-like protein.

Abstract: The present invention relates to a DNA ligation method. Specifically, a DNA complex comprising a three-stranded structure in each of the ends of double-stranded DNAs, one of which has single-stranded regions at the end, and the other of which does not have single-stranded regions at the end, is formed under the presence of a homologous recombinant protein. Moreover, according to needs, the DNA complex is introduced into host cells, and said cells are cultured.

Abstract: A method of amplifying a template DNA molecule in an isothermal reaction that can reduce background noise is provided. A method of amplifying a template DNA molecule using a strand-displacing DNA polymerase capable of carrying out isothermal amplification includes a step of conducting an amplification reaction with the addition of a single-strand DNA binding protein (SSB) from an extreme thermophile.

Abstract: An object of the present invention is to provide a nucleic acid amplification method for amplifying a desired nucleic acid while suppressing amplification of byproducts in a PCR reaction, a reagent kit used for nucleic acid amplification, a method of detecting single nucleotide polymorphism to detect single nucleotide polymorphism by utilizing that amplification of byproducts is suppressed in a PCR reaction, and a reagent kit used for detecting single nucleotide polymorphism. The method of amplifying nucleic acids by PCR is characterized by admixing in a reaction solution, a homologous recombinant protein which contains at least one of a RecA protein derived from Thermus thermophilus, and a modified RecA protein obtained by modification of the RecA protein and having a function similar to that of the RecA protein, and carrying out PCR.

Abstract: A DNA amplification method of amplifying DNA by PCR comprises a process of preparing a mixed solution for PCR reaction by mixing a template DNA, a primer DNA, a RecA protein derived from Thermus thermophilus (T. th. RecA protein) and a phage T4 gene 32 protein, and a process of amplifying DNA by subjecting the prepared mixed solution for PCR reaction to PCR reaction.

Abstract: An objective of this invention is to provide a method for detecting DNA polymorphism that has high sensitivity and efficiency and does not need long DNA searching region. A homologous recombination protein RecA makes partial triple strand DNA from target double DNA and oligonucleotide probe complementary to the DNA. The triple strand DNA maintains stable triple strand DNA after RecA protein is removed. The present inventors found that the thermostability of triple strand DNA changes greatly when there is a mismatch between target DNA and oligonucleotide probe because of the existence of polymorphism in the target DNA. Utilizing this change of thermostability, efficient detection of polymorphism in labeled DNA is possible by examining whether oligonucleotide probe is released and the triple strand DNA is solved after heat treatment of triple strand DNA formed using homologous recombination protein.

Abstract: The present invention provides methods of preparing a triple-stranded DNA molecule by forming a DNA and protein complex, which DNA has a linear double-stand molecule and a single-strand molecule where the linear single-stranded DNA is complementary to a 5′ end region of one strand in the linear double stranded DNA; and the protein component is a homogeneous recombinant protein and an exonuclease; and then the protein is removed from the complex; triple-stranded DNA; and methods of using the triple-stranded DNA to detect nucleic acid sequence.

Abstract: A preparation method of labeled DNA and use thereof are disclosed. More specifically, the invention relates to a preparation method of labeled DNA by preparation of a complex triple-stranded DNA through an deoxyoligonucleotide complementary to the deoxyoligonucleotide sequence of the 3′ terminal sequence of a certain double-stranded DNA followed by replacement of the 3′ terminal region of the plus strand of said double-stranded DNA with at least one labeled dNTP, and also to said immobilization method of a DNA obtained from the preparation method of the labeled (or modified) DNAs onto a solid support. These subject matters are mainly useful for preparation of labeled DNA molecules.

Abstract: A method for specifically cleaving a double-stranded DNA. The method comprises forming a three-stranded portion comprising the double-stranded DNA portion including the position to be cleaved or its vicinity and an oligonucleotide and treating the three-stranded protion with a nuclease.

Abstract: The present invention provides methods of preparing a triple-stranded DNA molecule by forming a DNA and protein complex, which DNA has a linear double-strand molecule and a single-strand molecule where the linear single-stranded DNA is complementary to a 5′ end region of one strand in the linear double stranded DNA; and the protein component is a homogeneous recombinant protein and an exonuclease; and then the protein is removed from the complex; triple-stranded DNA; and methods of using the triple-stranded DNA to detect nucleic acid sequences.

Abstract: An objective of this invention is to provide a method for detecting DNA polymorphism that has high sensitivity and efficiency and does not need long DNA searching region.