Mature miRNAs from total RNA are modified by extending the 3' end of the mature transcript through Poly(A) addition using E. coli Poly (A) Polymerase. The modified miRNAs then undergo universal reverse transcription using Oligo (dT)-universal tag primer to synthesize the first strand cDNA for all miRNAs.

The kit contains three tubes of reagents: gDNA Remover, miRNA RT Enzyme Mix and 4× miRNA RT Buffer.

Among them, gDNA Remover mainly includes concentrated DNase and buffer. It can degrade more than 95% of residual genomic DNA only needing to react at room temperature (19 ~ 27°C) for 5 minutes, which greatly reduces the interference to the results.

The miRNA RT Enzyme Mix mainly contains E. coli Poly(A) Polymerase, reverse transcriptase, and RNase Inhibitor. E. coli Poly (A) Polymerase not only has efficient Poly (A) tailing reaction efficiency, but also specifically recognizes mature single-stranded miRNA, thereby avoiding reverse transcription reaction of miRNA precursors with double-stranded structure. The mutant M-MLV reverse transcriptase has strong anti-interference ability and amplification ability.

The 4× miRNA RT Buffer reagent contains all raw materials and primers for Poly(A) tailing reaction and reverse transcription reaction, including Oligo(dT)-universal tag primer, buffer and dNTPs, and has been carefully optimized to ensure Poly (A) tailing reaction and reverse transcription reaction efficiently.