Barcoded cDNA library preparation for small RNA profiling by next-generation sequencing.

The characterization of post-transcriptional gene regulation by small regulatory (20-30 nt) RNAs, particularly miRNAs and piRNAs, has become a major focus of research in recent years. A prerequisite for characterizing small RNAs is their identification and quantification across different developmental stages, and in normal and disease tissues, as well as model cell lines. Here we present a step-by-step protocol for generating barcoded small RNA cDNA libraries compatible with Illumina HiSeq sequencing, thereby facilitating miRNA and other small RNA profiling of large sample collections.