Small RNA sequencing, also known as small RNAseq or sRNAseq, uses high-throughput sequencing technologies to get information about small non-coding RNA molecules. Small RNAs have a length between 20 and 200 nucleotides and are usually non-coding. These small non-coding RNAs include small nuclear RNA (snRNA), small nucleolar RNA (snoRNA), small conditional RNA (scRNA), piwi-interacting RNA (piRNA), microRNA (miRNA), YRNA (components of the Ro60 ribonucleoprotein particle), tRNA-derived small RNA (tsRNA), rRNA-derived small RNA (rsRNA), and small interfering RNA (siRNA). The function of these small RNas range from RNA interference, also known as RNAi, over RNA processing and modification, to gene silencing, protein stability and transport, and epigenetic modifications.
Thus, studying small RNAs, has a wide range of applications. With small RNA sequencing, the differential expression of all small RNAs in a sample can be determined. This also includes the expression profile of miRNAs and other small RNAs. By analyzing those expression profiles using small RNA sequencing, the understanding of cell regulation and dysregulation under pathological conditions can be increased. Thus, small RNA sequencing can be used to identify biomarkers for disease diagnostics or disease classification, such as cancer. As small RNAs play a crucial role in regulations, regulatory networks can be identified to increase the knowledge about developmental mechanisms of