Provided is a nucleoside derivative which has a high affinity for RNA. Use is made of a nucleoside derivative represented by either formula (1) or formula (2). (In formulae (1) and (2), Z represents a carbon atom or a nitrogen atom; R
1
represents a hydrogen atom or a hydroxyl-protecting group; and R
2
represents a hydrogen atom or a phosphodiester group).
提供了一种对RNA具有高亲和力的核苷衍
生物。使用的是由公式(1)或公式(2)所表示的核苷衍
生物。(在公式(1)和(2)中,Z代表碳原子或氮原子;R1代表氢原子或羟基保护基;R2代表氢原子或
磷酸二酯基团)。