Abstract
Small interfering RNAs (siRNAs) are small (typically 18-24 nucleotides) RNA molecules capable of silencing gene expression post-transcriptionally and as such, they provide a simple method by which the role of individual genes in complex cellular systems can be easily assessed. As siRNAs are easy to use experimentally, and can be designed to target any gene (including pathogens), their use is perfectly suited to and easily adapted to high-throughput genome-wide screening methodologies and a range of phenotypic assays. Here we describe the use of a large siRNA library (>8,000 genes targeted individually) to screen for and identify host factors functionally involved in the replication of a human herpesvirus (Herpes simplex virus type 1; HSV-1) (Griffiths et al., 2013; Griffiths, 2013).