PROBLEM TO BE SOLVED: To provide an efficient and simple method of producing nucleic acid aptamers, in particular DNA aptamers, which have a high specificity and affinity to a target.SOLUTION: A method for producing nucleic acid aptamers comprises: a complex formation step of forming a complex of a single stranded nucleic acid and a target by mixing a single stranded nucleic acid library with the target in a solution； an immobilization step of immobilizing the complex on a solid-phase carrier via a connector adsorbed to the target and/or the solid-phase carrier by mixing the solid-phase carrier with the solution after the previous step； a recovery step of recovering the complex immobilized on the solid-phase carrier from the solution； an amplification step of amplifying the single stranded nucleic acid in the complex after recovery by a nucleic acid amplification method； and a single stranded nucleic acid preparation step which forms an intramolecular conformation after making double stranded nucleic acid obtained from the amplification step single stranded. The single stranded nucleic acid obtained from the single stranded nucleic acid preparation step repeatedly undergoes each of the steps from complex formation to the single stranded nucleic acid preparation a plurality of times using a new single stranded library.SELECTED DRAWING: Figure 1【課題】標的物質との特異性及び結合性が高い核酸アプタマー、特にDNAアプタマーを効率的、かつ簡便に製造する方法の提供。【解決手段】一本鎖核酸ライブラリーと標的物質とを溶液中で混合して、一本鎖核酸と標的物質の複合体を形成させる複合体形成工程、前工程後の溶液と固相担体を混合して、標的物質及び／又は固相担体に吸着させた結合子を介して複合体を固相担体に固定化する固定化工程、固相担体に固定化された複合体を溶液から回収する回収工程、複合体中の一本鎖核酸を回収後、核酸増幅法によって増幅させる増幅工程、及び増幅工程で得られた二本鎖核酸を一本鎖化した後、分子内立体構造を形成させる一本鎖核酸調製工程を含む核酸アプタマーの製造方法。一本鎖核酸調製工程で得られた一本鎖核酸を新たな一本鎖ライブラリーを用いて複合体形から一本鎖核酸迄の諸工程を複数回繰り返して行う、製造方法。【選択図】図１
