RT-Hpro-PCR: A MicroRNA Detection System Using a Primer with a DNA Tag

MicroRNAs (miRNAs) are short RNAs that regulate the expression of complementary messenger RNAs and are involved in numerous human diseases. However, current detection techniques lack the sensitivity to detect miRNAs of low abundance. Moreover, at a length of 20–25 bases, miRNAs are too short for the reverse transcription (RT) polymerase chain reaction (PCR). Here we have developed a new, rapid, and simple miRNA detection system utilizing an RT primer containing a DNA tag at the 5′-end to increase the length of the cDNA. This strategy increases the length of the hybridized tagged primer and the complementary template DNA, as well as the melting temperature of the primer ⋅ template DNA duplex. PCR efficiency is thus increased, thereby enhancing miRNA detection sensitivity.