Dengue is a mosquito-borne viral infection that is one of the leading causes of illness and death in the subtropical and tropical areas of the world. The incidence of dengue is growing rapidly, threatening more than 2.5 billion people in more than 100 countries. Symptoms of dengue virus infection can be severe with fatality rates as high as 10% in the first week if proper treatment is not administered. Because the dengue virus is a single-strand RNA, RT-PCR is the most widely used technique for identification. However, RT-PCR is expensive, time-consuming, typically takes 1-2 days for results and not suitable in remote areas.
Researchers at the Biodesign Institute of Arizona State University have developed a novel tool for rapid and cost-effective detection of dengue virus. Using a DNA tetrahedron having a single-strand DNA edge for annealing complementary target RNA, dengue virus RNA sequences could be detected with limits as low as sub-attomolar. The fluorescence signal from the DNA tetrahedron was amplified using novel tandem toehold-mediated displacement reactions (tTMDR). Each RNA target can be recycled many times during the tTMDR process to form an amplifying loop for enhancing the fluorescence signal.
This novel tool allows for extremely sensitive detection of dengue virus RNA for critical early stage diagnosis and treatment.
• Early detection of dengue virus and any other RNA virus infection
Benefits and Advantages
• As few as 6 copies of RNA per sample can be detected
• Single molecule sensitivity
o The detection limit of this method could reach sub-attomolar
• Amplified at room temperature without any additional equipment
• The tetrahedron system can be formed with high efficiency and repeatability