Preparation of Small RNA NGS Libraries from Biofluids.

Next generation sequencing (NGS) is a powerful method for transcriptome analysis. Unlike other gene expression profiling methods, such as microarrays, NGS provides additional information such as splicing variants, sequence polymorphisms, and novel transcripts. For this reason, NGS is well suited for comprehensive profiling of the wide range of extracellular RNAs (exRNAs) in biofluids. ExRNAs are of great interest because of their possible biological role in cell-to-cell communication and for their potential use as biomarkers or for therapeutic purposes. Here, we describe a modified protocol for preparation of small RNA libraries for NGS analysis. This protocol has been optimized for use with low-input exRNA-containing samples, such as plasma or serum, and has modifications designed to reduce the sequence-specific bias typically encountered with commercial small RNA library construction kits.