0 L Zheng PJ Wayper AJ Gibbs M Fourment BC Rodoni MJ Gibbs. 2008 Accumulating Variation at Conserved Sites in Potyvirus Genomes is Driven by Species Discovery and Affects Degenerate Primer Design PLoS ONE <p>Unknown and foreign viruses can be detected using degenerate primers targeted at conserved sites in the known viral gene sequences. Conserved sites are found by comparing sequences and so the usefulness of a set of primers depends crucially on how well the known sequences represent the target group including unknown sequences.</p> http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001586