nucleic acid sequencing method rna-seq method RNA-Seq is an approach for transcriptome profiling which uses deep-sequencing technologies. RNA-Seq, also called "Whole Transcriptome Shotgun Sequencing" ("WTSS") and dubbed "a revolutionary tool for transcriptomics", refers to the use of High-throughput sequencing technologies to sequence cDNA in order to get information about a sample's RNA content, a technique that is quickly becoming invaluable in the study of diseases like cancer. Thanks to the deep coverage and base level resolution provided by next-generation sequencing instruments, RNA-Seq provides researchers with efficient ways to measure transcriptome data experimentally, allowing them to get information such as how different alleles of a gene are expressed, detect post-transcriptional mutations or identifying gene fusions.