Fig. 1.

Positive and negative controls for HPV16 and HPV 18 with real-time PCR. a Positive and negative controls for HPV16; b Positive and negative controls for HPV18. Standard curve 1–5, 10-fold diluted HPV16 E6 or HPV18 E6 plasmid DNA ranging from 1 ng/well to 0.1 pg/well. Positive control 1, cilnical DNA sample added with 0.1 pg HPV16 E6 or HPV18 E6 DNA. Positive control 2, 50 ng Hela cell DNA. Negative control 1, pure water. Negative control 2, pure water instead of 2 × master mixture. Negative control 3, pure water instead of positive control DNA