Patent ID: 7851157

Claim:
An oligonucleotide derivative represented by the following General Formula (1): (where A 1 and A 2 may be the same or different and each represent a hydrogen atom, a hydroxyl group, an alkyl group, which may be substituted by a substituent; n represents an integer of 10 to 50; Y 2 represents a hydrogen atom, a hydroxyl group, an alkoxy group, or a 2-cyanoethoxy group or may be bound to the carbon atom at the 4′-position of the ribose to form a ring; B 2 represents a natural or non-natural nucleotide base; R 2 represents a substituent bound to an amino group of the nucleotide base and is a hydrogen atom, an acyl group, a thioacyl group, an alkoxycarbonyl group, an alkoxythiocarbonyl group, a carbamoyl group which may be substituted by an alkyl group, a thiocarbamoyl group which may be substituted by an alkyl group, or an alkyl group (which may be bound to an alkyl group, an alkenyl group, an alkynyl group, or a phenyl group); and B 1 represents a substituent represented by the following General Formula (2): where B represents a natural or non-natural nucleotide base; R represents a substituent bound to an amino group of the nucleotide base and is a hydrogen atom, an acyl group, a thioacyl group, an alkoxycarbonyl group, an alkoxythiocarbonyl group, a carbamoyl group which may be substituted by an alkyl group, a thiocarbamoyl group which may be substituted by an alkyl group, or an alkyl group (which may be bound to an alkyl group, an alkenyl group, an alkynyl group, or a phenyl group); X represents an oxygen ion, a sulfur ion, BH 3 , OCH 3 , or CH 3 ; and Y represents a hydrogen atom, a hydroxyl group, an alkoxy group, or a 2-cyanoethoxy group or may be bound to the carbon atom at the 4′-position of the ribose to form a ring, wherein at least one of R and R 2 is not a hydrogen atom).