Here, we present a highly specific, sensitive and cost-effective system to quantify microRNA (miRNA) expression based on two-step RT-qPCR with EvaGreen detection chemistry, called linear-hairpin variable primer RT-qPCR. It takes advantage of the novel designed variable primer, which is initially designed to be linear, extending to form a hairpin structure and replacing the target miRNA for cyclic RT. Then the RT product is quantified by conventional EvaGreen based qPCR. The results show that this method has a dynamic range of 8 logs and the sensitivity is sufficient to directly detect down to 4 target miRNA molecules with a total analysis time of less than 2 hours. It is capable of discriminating between similar miRNAs, leading to an accurate representation of the mature miRNA content in a sample. The RT step can be multiplexed and the 8 miRNA profiles measured in 7 mouse tissues by this method show an excellent correlation with the commercial standard TaqMan RT-qPCR assays (r² = 0.9881).

DNA amplification is one of the most valuable tools for the clinical diagnosis of nucleic acid-related diseases, but current techniques for DNA amplification are based on intermolecular polymerization reactions, resulting in the risk of errors in the intermolecular reaction pattern.

A novel self-assembled DNA nanostructure was designed as a FRET nanoflare for ATP imaging in live cells.