Composition for Point-of-Care Nucleic Acid Detection Using Universal Hybridization Chain Reaction

Composition for Point-of-Care Colorimetric Nucleic Acid Detection Based on Universal Hybridization Chain Reaction for G-Quadruplex Formation

This technology is a nucleic acid detection composition consisting of a hairpin-type trigger monomer that binds to a target nucleic acid and two types of universal hairpin monomers. In the presence of a target, an enzyme-free hybridization chain reaction (uHCR) repeatedly forms G-quadruplexes, which bind with hemin to generate a colorimetric signal visible to the naked eye.

While PCR-based nucleic acid testing offers excellent specificity and sensitivity, it has been difficult to use for point-of-care testing due to the need for expensive equipment, enzymes, and complex temperature control. Existing HCR, an isothermal amplification technique, also had limitations, requiring the entire hairpin set to be redesigned whenever the target changed.

This technology simplifies design by allowing the reuse of hairpin monomers while only changing the target-binding region of the trigger monomer. It amplifies at room temperature, enabling quantitative colorimetric readout without specialized equipment. It distinguishes various targets, including tumor microRNAs and genetic mutations, even down to single-nucleotide differences, and provides accurate detection in biological fluids. Applicable to point-of-care diagnostics for infectious pathogens and cancer biomarker test kits, it reduces equipment dependency and significantly lowers analysis costs.

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Key Features:

• A hairpin-type trigger monomer comprising a first region complementary to a target nucleic acid, a second region forming a stem, and a third region forming a loop
• A nucleic acid detection composition comprising a first hairpin monomer that hybridizes with the trigger monomer and a second hairpin monomer that hybridizes with the first hairpin monomer
• The first region consists of a 10 to 50 nucleotide sequence complementary to the target nucleic acid, and the second region further includes a 6-nucleotide tail portion
• A step of adding the nucleic acid detection composition to a sample to amplify the target nucleic acid, and reacting it with hemin and a chromogenic substrate to determine the presence of the target via absorbance

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This invention was developed with support from the Ministry of Science and ICT for the development of non-viral gene therapy nano-assembly skin delivery technology.

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