Small RNA Profiling by Next-Generation Sequencing Using High-Definition Adapters

Abstract

Next-generation sequencing (NGS) of small RNA (sRNA) cDNA libraries permits the identification and characterization of sRNA species de novo. However, the method through which these libraries are constructed can often introduce artifacts such as over- or underrepresentation of specific sequences or adapter oligonucleotides due to sequence biases held by the enzymes used. In this chapter we describe a protocol for sRNA library construction making use of high-definition (HD) adapters for the Illumina sequencing platform, which reduce ligation bias. This protocol leads to drastically reduced direct 5'/3' adapter ligation products and can be used for the synthesis of sRNA libraries from total RNA or sRNA of various plant, animal, and fungal samples. This protocol also includes a method for total RNA extraction from plant leaf and cultured cells or body fluids.