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In Vitro Selection of Circular DNA Aptamers for Biosensing Applications
Author(s) -
Liu Meng,
Yin Qingxin,
Chang Yangyang,
Zhang Qiang,
Brennan John D.,
Li Yingfu
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201901192
Subject(s) - aptamer , dna , computational biology , circular dna , biology , rolling circle replication , biosensor , systematic evolution of ligands by exponential enrichment , microbiology and biotechnology , genetics , biochemistry , rna , gene , dna replication , genome
We report on the first effort to select DNA aptamers from a circular DNA library, which resulted in the discovery of two high‐affinity circular DNA aptamers that recognize the glutamate dehydrogenase (GDH) from Clostridium difficile, an established antigen for diagnosing Clostridium difficile infection (CDI). One aptamer binds effectively in both the circular and linear forms, the other is functional only in the circular configuration. Interestingly, these two aptamers recognize different epitopes on GDH, demonstrating the advantage of selecting aptamers from circular DNA libraries. A sensitive diagnostic test was developed to take advantage of the high stability of circular DNA aptamers in biological samples and their compatibility with rolling circle amplification. This test is capable of identifying patients with active CDI using stool samples. This work represents a significant step forward towards demonstrating the practical utility of DNA aptamers in clinical diagnosis.