The invention discloses a
nucleic acid aptamer capable of recognizing and combining different epitopes of a
thyroid stimulating
hormone receptor as well as a
screening method and application of the
nucleic acid aptamer. The invention provides a
nucleic acid aptamer capable of identifying and combining a
thyroid stimulating
hormone receptor, which is a single-chain
DNA molecule as shown in SEQ ID No.1, 3, 4 or 5. The invention also provides a complete set of nucleic acid aptamer consisting of the nucleic acid aptamer and a nucleic acid aptamer as shown in SEQ ID No.2 or 6. In addition, the invention also provides a method for screening different
epitope aptamers, which comprises the following steps of: occupying corresponding epitopes on a
target protein by using the screened aptamers, and then carrying out subsequent screening, so that the screened aptamers bound to target other different epitopes on the
target protein. Based on the principle, the invention has important research significance on screening of a certain
target protein to obtain nucleic acid aptamers for identifying different sites, development of
protein detection reagents and bivalent nucleic acid aptamers for enhancing affinity between the nucleic acid aptamers and targets and the like.