Abstract: This invention is intended to enhance and improve the resistance of a single- or double-stranded nucleic acid fragment comprising a base sequence of a functional nucleic acid to degradation by nucleolytic enzymes in a simple and cost-effective manner. The single- or double-stranded nucleic acid fragment comprises, ligated to at least one end thereof, hairpin-shaped DNA comprising: (A) a nucleic acid region comprising 2 to 5 arbitrary nucleotides; (B) a nucleic acid region comprising a “gna” or “gnna” base sequence, wherein each “n” represents “g”, “t”, “a”, or “c”, a base analogue, or a modified base; and (C) a nucleic acid region comprising a base sequence complementary to the nucleic acid region (A), sequentially from the 5? end toward the 3? end.

Abstract: An object of the present invention is to provide a convenient and low-cost method for enhancing the stability of a DNA aptamer and/or its capacity to bind to a target molecule, and a DNA aptamer obtained by the method. The object is solved by substituting an internal hairpin structure (stem-loop structure) of the DNA aptamer with a structure called mini-hairpin structure and optionally increasing GC pairs in a stem portion of the DNA aptamer.

Abstract: The purpose of the present invention is to provide an aptamer to a cancer cell, said aptamer being superior to conventional aptamers in binding ability, specificity, and/or stability. To solve this problem, provided is a DNA aptamer binding to a cancer cell, said DNA aptamer containing an artificial base(s).

Abstract: An object of the present invention is to provide a convenient and low-cost method for enhancing the stability of a DNA aptamer and/or its capacity to bind to a target molecule, and DNA aptamer obtained by the method. The object is solved by substituting an internal hairpin structure (stem-loop structure) of the DNA aptamer with a structure called mini-hairpin structure and optionally increasing GC pairs in a stem portion of the DNA aptamer.

Abstract: The purpose of the present invention is to provide an aptamer for vWF, which is superior in a binding ability, a dissociation rate, and/or stability to the conventional nucleic acid aptamers. The present invention can solve the problem by a DNA aptamer which contains artificial nucleotides and binds to vWF.

Abstract: This invention is intended to enhance and improve the resistance of a single- or double-stranded nucleic acid fragment comprising a base sequence of a functional nucleic acid to degradation by nucleolytic enzymes in a simple and cost-effective manner. The single- or double-stranded nucleic acid fragment comprises, ligated to at least one end thereof, hairpin-shaped DNA comprising: (A) a nucleic acid region comprising 2 to 5 arbitrary nucleotides; (B) a nucleic acid region comprising a “gna” or “gnna” base sequence, wherein each “n” represents “g”, “t”, “a”, or “c”, a base analogue, or a modified base; and (C) a nucleic acid region comprising a base sequence complementary to the nucleic acid region (A), sequentially from the 5? end toward the 3? end.

Abstract: An object of the present invention is to develop and provide a method for efficiently and conveniently producing a nucleic acid aptamer, particularly, a DNA aptamer, having high specificity for and high binding activity against a target substance.

Abstract: An object of the present invention is to develop and provide a method for efficiently producing a nucleic acid aptamer, particularly, a DNA aptamer, having higher specificity and binding activity against a target substance than those of nucleic acid aptamers obtained by conventional methods. The present invention provides a transcribable or replicable nucleic acid aptamer comprising a natural nucleotide and a non-natural nucleotide having an artificial base-pairable artificial base. The present invention also provides a method for sequencing a non-natural nucleotide-containing single-stranded nucleic acid molecule selected from a single-stranded nucleic acid library.

Abstract: An object of the present invention is to develop and provide a method for efficiently producing a nucleic acid aptamer, particularly, a DNA aptamer, having higher specificity and binding activity against a target substance than those of nucleic acid aptamers obtained by conventional methods. The present invention provides a transcribable or replicable nucleic acid aptamer comprising a natural nucleotide and a non-natural nucleotide having an artificial base-pairable artificial base. The present invention also provides a method for sequencing a non-natural nucleotide-containing single-stranded nucleic acid molecule selected from a single-stranded nucleic acid library.

Abstract: An object of the present invention is to develop and provide a method for efficiently and conveniently producing a nucleic acid aptamer, particularly, a DNA aptamer, having high specificity for and high binding activity against a target substance.

Abstract: An object of the present invention is to develop and provide a method for efficiently and conveniently producing a nucleic acid aptamer, particularly, a DNA aptamer, having high specificity for and high binding activity against a target substance.

Abstract: This invention is intended to enhance and improve the resistance of a single- or double-stranded nucleic acid fragment comprising a base sequence of a functional nucleic acid to degradation by nucleolytic enzymes in a simple and cost-effective manner. The single- or double-stranded nucleic acid fragment comprises, ligated to at least one 3? end thereof, a hairpin-shaped DNA comprising: (A) a nucleic acid region consisting of 2 to 5 arbitrary nucleotides; (B) a nucleic acid region consisting of a “gna” or “gnna” base sequence, wherein each “n” represents “g”, “t”, “a”, or “c”, a base analogue, or a modified base; and (C) a nucleic acid region consisting of a base sequence complementary to the nucleic acid region (A), sequentially ligated from the 5? end toward the 3? end, wherein at least one of two 3? terminal nucleotides from at least one 3? end of the single-stranded nucleic acid fragment or the double-stranded nucleic acid fragment is modified.

Abstract: It is an object of the present invention to provide quenching or fluorescent nucleic acid base analogs and applications thereof. The quencher of the present invention has a 2-nitropyrrole structure represented by Formula I: [Formula 1] (in Formula I, R1 and R2 are groups independently selected from the group consisting of: ribose and deoxyribose; hydrogen, hydroxyl and SH groups, and halogens; substituted or unsubstituted alkyl, alkenyl, and alkynyl groups each having 2 to 10 carbon atoms; one or more five-membered heterocyclic rings, one or more six-membered heterocyclic rings, and one or more fused heterocyclic rings, these heterocylic rings containing nitrogen or sulfur, and one or more aromatic rings; sugars, sugar chains, amino acids, and peptides; and fluorescent molecules linked via linkers).

Abstract: This invention is intended to enhance and improve the resistance of a single- or double-stranded nucleic acid fragment comprising a base sequence of a functional nucleic acid to degradation by nucleolytic enzymes in a simple and cost-effective manner. The single- or double-stranded nucleic acid fragment comprises, ligated to at least one end thereof, hairpin-shaped DNA comprising: (A) a nucleic acid region comprising 2 to 5 arbitrary nucleotides; (B) a nucleic acid region comprising a “gna” or “gnna” base sequence, wherein each “n” represents “g”, “t”, “a”, or “c”, a base analogue, or a modified base; and (C) a nucleic acid region comprising a base sequence complementary to the nucleic acid region (A), sequentially from the 5? end toward the 3? end.