Fig. 3

Boxplots representing the amount of A GAPDH; B PhHV-1; C HPV16; and D PsV (EGFP) DNA in the respective samples after various centrifugation steps. Results are presented as ng, arbitrary copies, and DNA copies. All 1 ml samples were spiked with the same amount of PhHV-1 DNA, HPV16 plasmid DNA and HPV16 PsV (EGFP). The samples were centrifuged at 1000×g at 4 °C for 5 min or at 3000×g at 4 °C for 1 h. Centrifugation at 1000×g was performed before both PEG precipitation protocols, resulting in two data points per ID for this arm. Significant differences between the pellet and supernatant for centrifugation conditions are presented in the figure