False positives identified by each pipeline in the negative sample of increment 2 (NIBSC negative control), when using the SIB common database. In order to compare results across the pipelines, we only show the family to which the false positive viruses identified by each pipeline belong (in red). The pictogram at the left of the family name gives an indication of the characteristics of the virus (envelope (green), DNA (blue; single or double stranded, linear or circular) or RNA (red, negative stranded if dotted line). Note that pipeline C is absent as it only returned results using its own in-house database, and not with the SIB common database.