Figure 1. miRNA detection. (A) Total RNA was extended by the addition of a poly(A) tail to the 3' end using poly(A) polymerase. Hybridization of the adaptor was followed by reverse transcription to synthesize first-strand. RT-qPCR was then performed using a universal reverse primer and miRNA-specific forward primer. (B) An example of amplification curve of miR-144 in young and old tissues. (C) After amplification, the end-product was size-fractionated and visualized by ethidium bromide agarose gels.