Nucleic Acids Research Advance Access first published online on January 7, 2009
This version published online on February 8, 2009
Nucleic Acids Research, doi:10.1093/nar/gkn1024
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Methods Online |
Sensitive fluorescence detection of nucleic acids based on isothermal circular strand-displacement polymerization reaction
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Biomedical Engineering Center, Institute of Biological Technology, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, College of Material Science and Engineering, Hunan University, Changsha 410082, P.R. China
*To whom correspondence should be addressed. Tel/Fax: +86 731 8821566; Email: kmwang{at}hnu.cn
Received May 6, 2008. Revised December 6, 2008. Accepted December 9, 2008.
Here we have developed a sensitive DNA amplified detection method based on isothermal strand-displacement polymerization reaction. This method takes advantage of both the hybridization property of DNA and the strand-displacement property of polymerase. Importantly, we demonstrate that our method produces a circular polymerization reaction activated by the target, which essentially allows it to self-detect. Functionally, this DNA system consists of a hairpin fluorescence probe, a short primer and polymerase. Upon recognition and hybridization with the target ssDNA, the stem of the hairpin probe is opened, after which the opened probe anneals with the primer and triggers the polymerization reaction. During this process of the polymerization reaction, a complementary DNA is synthesized and the hybridized target is displaced. Finally, the displaced target recognizes and hybridizes with another probe, triggering the next round of polymerization reaction, reaching a target detection limit of 6.4 x 10–15 M.