Real-time PCR: Advancing RNA Interference and MicroRNA Studies

The endogenous small RNAs known as microRNAs (miRNAs) found in the genomes of both animals and plants are highly conserved by evolution, suggesting a fundamental biological function. MicroRNAs are cleaved from larger hairpin precursors (Figure 1), and it is the mature, cleaved, approximately 22-nucleotide miRNA that currently is the focus of most research. The inherent homology between the longer pre-miRNA and the mature, active miRNA makes it difficult to preferentially detect the active molecule using traditional hybridization-based methods. This has contributed to the challenges of accurately quantifying and elucidating the role of miRNAs in different tissues, developmental stages and disease states.