miRNA 1st strand cDNA Synthesis Kit (by tailing A) is a kit for microRNA (miRNA) reverse transcription (RT) by tailing A. Poly A polymerase (PAP) adds a Poly(A) tail to the 3' end of miRNA or total RNA, and then universal reverse transcription primers initiate RT reaction with reverse transcriptase. HiScript miRNA Enzyme Mix contains bioengineered reverse transcriptase and PAP. Combined with the optimized buffer, the reverse transcription of non-miRNAs is effectively inhibited, achieving highly specific qPCR results. 2 × miRNA RT Mix and HiScript miRNA Enzyme Mix contains all components required for miRNA tailing and reverse transcription. Two reactions can be performed simultaneously in one tube.