Safety, quality, and efficacy of biologics are the basis for approving and authorizing through state regulatory bodies. Safety is ensured among other activities by quality controls during the manufacturing process. This also includes testing for unwanted agents which pose a threat to human health. This safety control step is called Adventitious Agent Testing. Here, we specifically deal with viral contamination and name this topic Adventitious Virus Testing (AVT). This white paper provides you with required knowledge related to the involved regulatory authorities and scientific technologies and disciplines: Next Generation Sequencing (NGS), Bioinformatics and Computer System Validation (CSV). Before starting, let us take a look at the history of AVT, which was not a matter of course.