title: Amplified detection of nucleic acid by G-quadruplex based hybridization chain reaction.
abstract: A protein-free, isothermal, self-amplified nucleic acid sensing system which was a G-quadruplex integrated hybridization chain reaction (GQ-HCR) system was developed. The G-quadruplex was closed two-thirds in the loop and one-third in the stem of one of the GQ-HCR hairpin probes. In the absence of the target molecule, the GQ-HCR probes stayed as inactive meta-stable hairpin structures and the G-quadruplex was inert. Reversely, the GQ-HCR probes could be cross-opened to start a hybridization chain reaction and the closed G-quadruplex could be released to be free when the GQ-HCR probes came across the target molecule. The GQ-HCR nucleic acid sensing system could detect as low as 7.5 nM ssDNA or RNA by the colorimetric method and 4 nM ssDNA by the fluorometric method. Less than 10 copies of dsDNA template could also be detected when PCR was combined with the GQ-HCR system (PCR+GQ-HCR). Because of these advantages, the GQ-HCR system was also studied for application in visual chip detection to obtain a satisfactory repeatable and specific result.
authors: Natural Products Research Center, Chengdu Institution of Biology, Chinese Academy of Science, Sichuan, Chengdu 610041, PR China.
authors: Juan
authors: J
authors: Dong
authors: Xin
authors: X
authors: Cui
authors: Yun
authors: Y
authors: Deng
authors: Zhuo
authors: Z
authors: Tang
mesh_terms: D001483:Base Sequence; D003124:Colorimetry / Q000379:methods; D005470:Fluorometry / Q000379:methods; D054856:G-Quadruplexes; D008969:Molecular Sequence Data; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D009693:Nucleic Acid Hybridization / Q000379:methods*; D009696:Nucleic Acids / Q000032:analysis* / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D014439:Tyramine / Q000737:chemistry
chemical_list: D009696:Nucleic Acids; D014439:Tyramine