Fig. 2

Nuclease treatment significantly enriches for virus reads. To test nuclease treatment in metagenomic sequencing, plasma samples were spiked with four different viruses (adenovirus, HHV-5, influenzavirus, poliovirus) and processed with and without incubation at 37 °C (I +/−), nuclease treatment (N +/−) and freeze-thaw cycles (FT +/−), respectively. The experiment was performed in duplicates. a Fraction of sequencing reads that passed quality filtering. b Distribution of sequencing reads into the different taxonomic categories viral, human, bacterial, and unknown origin. c Number of reads (upper panels) and fraction of all quality passing reads (lower panels) obtained for each individual virus