The L396 and R596 real-time PCR assays could detect as few as 10 copies of plasmid DNA per reaction with amplifi cation effi ciencies of 99.6% [slope -3.33 and r 2 = 0.99] (Figure, left panels) and 99.2% [slope -3.34 and r 2 = 1.00] (Figure, right panels) , respectively. No amplifi cation was obtained by either assay with pooled total nucleic acid extracts from respiratory samples from healthy humans or from other common DNA respiratory viruses, including adenovirus, human bocavirus, or herpesviruses.