1. In Vitro Selection of a DNA Aptamer Targeting Degraded Protein Fragments for Biosensing.
- Author
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Liu, Meng, Wang, Jiayi, Chang, Yangyang, Zhang, Qiang, Chang, Dingran, Hui, Christy Y., Brennan, John D., and Li, Yingfu
- Subjects
APTAMERS ,DEOXYRIBOZYMES ,CLOSTRIDIOIDES difficile ,DNA ,PROTEINS ,BIODEGRADATION - Abstract
Protein biomarkers often exist as degradation fragments in biological samples, and affinity agents derived using a purified protein may not recognize them, limiting their value for clinical diagnosis. Herein, we present a method to overcome this issue, by selecting aptamers against a degraded form of the toxin B protein, which is a marker for diagnosing toxigenic Clostridium difficile infections. This approach has led to isolation of a DNA aptamer that recognizes degraded toxin B, fresh toxin B, and toxin B spiked into human stool samples. DNA aptamers selected using intact recombinant toxin B failed to recognize degraded toxin B, which is the form present in stored stool samples. Using this new aptamer, we produced a simple paper‐based analytical device for colorimetric detection of toxin B in stool samples, or in the NAP1 strain of Clostridium difficile. The combined aptamer‐selection and paper‐sensing strategy can expand the practical utility of DNA aptamers in clinical diagnosis. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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