Detection methods targeting the positive‐ and negative‐sense RNA transcripts from plus‐stranded RNA viruses

The largest group of viruses in the Baltimore classification system comprises viruses with a positive‐sense, single‐stranded RNA genome. Once the viral genome is released into the cytoplasm of a specific host cell following virus entry, it functions directly as an mRNA, and the virus‐encoded proteins that are essential for genome replication are produced by the translation apparatus of the host cell. The positive‐sense genome is replicated in two stages, initially the positive strand is copied to make a negative‐sense RNA, which then functions as the template for transcription of many new positive‐sense genomes. Virus infections can be detected at different stages throughout the infection cycle for diagnostic and scientific purposes. Here, the advantages and disadvantages of some of the relevant methods for genome detection will be briefly reviewed with special emphasis on techniques allowing strand‐specific RNA detection. Furthermore, tools of the future are considered.