title: Long-tail probe-mediated cycled strand displacement amplification: label-free, isothermal and sensitive detection of nucleic acids.
abstract: We design a long-tail shaped DNA probe for the label-free, isothermal and sensitive detection of nucleic acids based on cycled strand displacement amplification (Ltail-CSDA). The long-tail probe, a stem-loop structure with a long poly(T) tail at 5'-termini, integrates target-binding and amplification and signaling within one multifunctional design. The specific binding between the long-tail probe and the target triggers a polymerization reaction, during which a long dsDNA product is synthesized and the hybridized target is displaced by the strand displacement activity of polymerase. The displaced target forms another specific probe-target binding and prompts cycled polymerization reactions. The proposed Ltail-CSDA has the distinct advantages of its isothermal nature, free-label, simplicity and attomolar sensitivity compared with other existing technologies. More significantly, the dynamic range of the method is extremely large, covering nine orders of magnitude. Using total RNA samples extracted from hepatitis C virus (HCV) as targets, we further demonstrate the detection capability of the method for complex nucleic acid samples, indicating its potential applicability for clinic molecular diagnostic assays.
authors.affiliation: College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Su
authors.forename: Jiabao
authors.initials: J
authors.lastname: Long
authors.forename: Qiuping
authors.initials: Q
authors.lastname: Guo
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Meng
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Tan
authors.forename: Qingyun
authors.initials: Q
authors.lastname: Cai
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Chen
authors.forename: Xiangxian
authors.initials: X
authors.lastname: Meng
mesh_terms: D001665:Binding Sites; D004247:DNA / Q000737:chemistry*; D015342:DNA Probes / Q000138:chemical synthesis / Q000737:chemistry*; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry; D005456:Fluorescent Dyes; D016174:Hepacivirus / Q000737:chemistry; D055029:Inverted Repeat Sequences; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D009693:Nucleic Acid Hybridization; D012367:RNA, Viral / Q000032:analysis*; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence; D013696:Temperature
chemical_list: D015342:DNA Probes; D005456:Fluorescent Dyes; D012367:RNA, Viral; D004247:DNA; D004259:DNA-Directed DNA Polymerase
keywords: Cycled strand displacement amplification; Isothermal; Label-free; Long-tail probe