Fig. 3.

Real time PCR for HPV viral load. DNA for HPV-16 positive oropharyngeal cancers were subjected to PCR in an iCycler BioRad Appartus with specific HPV-16 primers in a SYBR green I containing iQ Supermix (BioRad Lab, Hercules, CA, USA). The graph is the output from the apparatus; black lines are fivefold dilution of a HPV-16 plasmid from 1.94 × 10⁷ to 3.1 × 10⁴ viral copy; grey lines are negative controls without DNA. In the right panel the calculated viral load for each sample is shown