Detection of EBV DNA by real-time quantitative PCR for the BamHI-W region. A amplification plot of fluorescence intensity against the PCR cycle. Each plot corresponds to a particular input target quantity marked by a corresponding symbol. The X axis denotes the cycle number of a quantitative PCR reaction. The Y axis denotes the ΔRn, which is the fluorescence intensity over the background
. B plot of the threshold cycle (CT) against the input target quantity (common log scale). The input target quantity was expressed as copies of EBV DNA. The correlation coefficient is 0.994.
Comparison of plasma cell-free EBV DNA in NPC and control subjects. The categories (NPC and control subjects) are plotted on the X axis. Results from NPC and control subjects are indicated by ○ and ⋄, respectively. The Y axis denotes the concentration of cell-free EBV DNA (copies of EBV DNA/ml of plasma) detected by the BamHI-W region PCR system.
Plasma cell-free EBV DNA in NPC subjects before and after radiotherapy. The X axis marks each of the 15 subjects studied. The Y axis denotes the amount of cell-free EBV DNA (expressed as copies of EBV DNA/ml of plasma) detected by the BamHI-W region PCR system. Data before and after radiotherapy are plotted as ▪ and ▨, respectively. For visual clarity, the seven cases with no detectable EBV DNA after radiotherapy are grouped together on the left of the graph. These cases are followed by the eight cases with detectable levels of EBV DNA after radiotherapy.