Schematic showing stem-loop RT-PCR miRNA assays. A. Stem-loop RT followed by end-point PCR. Stem-loop RT primers bind to the 3' portion of miRNA molecules, initiating reverse transcription of the miRNA. Then, the RT product is amplified using a miRNA specific forward primer and the universal reverse primer. B. SYBR Green I assay. C. Universal ProbeLibrary (UPL) probe assay. Highlighted in yellow is the UPL probe #21 binding site.